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  • Pig trade networks through live pig markets in Guangdong Province, China
    Transbound. Emerg. Dis. (IF 3.554) Pub Date : 2020-01-13
    Yin Li; Baoxu Huang; Chaojian Shen; Chang Cai; Youming Wang; John Edwards; Guihong Zhang; Ian D. Robertson

    This study used social network analysis to investigate the indirect contact network between counties through the movement of live pigs through four wholesale live pig markets in Guangdong Province, China. All 14,118 trade records for January and June 2016 were collected from the markets and the patterns of pig trade in these markets analysed. Maps were developed to show the movement pathways. Evaluating the network between source counties was the primary objective of this study. A 1‐mode network was developed. Characteristics of the trading network were explored, and the degree, betweenness and closeness were calculated for each source county. Models were developed to compare the impacts of different disease control strategies on the potential magnitude of an epidemic spreading through this network. The results show that pigs from 151 counties were delivered to the four wholesale live pig markets in January and/or June 2016. More batches (truckloads of pigs sourced from one or more piggeries) were traded in these markets in January (8,001) than in June 2016 (6,117). The pigs were predominantly sourced from counties inside Guangdong Province (90%), along with counties in Hunan, Guangxi, Jiangxi, Fujian and Henan provinces. The major source counties (46 in total) contributed 94% of the total batches during the two‐month study period. Pigs were sourced from piggeries located 10 to 1,417 km from the markets. The distribution of the nodes' degrees in both January and June indicates a free‐scale network property, and the network in January had a higher clustering coefficient (0.54 vs. 0.39) and a shorter average pathway length (1.91 vs. 2.06) than that in June. The most connected counties of the network were in the central, northern and western regions of Guangdong Province. Compared with randomly removing counties from the network, eliminating counties with higher betweenness, degree or closeness resulted in a greater reduction of the magnitude of a potential epidemic. The findings of this study can be used to inform targeted control interventions for disease spread through this live pig market trade network in south China.

    更新日期:2020-01-14
  • CMTV‐like ranavirus infection associated with high mortality in captive catfish‐like loach, Triplophysa siluorides, in China
    Transbound. Emerg. Dis. (IF 3.554) Pub Date : 2020-01-13
    Lishuang Deng; Yi Geng; Ruoxuan Zhao; Matthew J. Gray; Kaiyu Wang; Ping Ouyang; Defang Chen; Xiaoli Huang; Zhengli Chen; Chao Huang; Zhijun Zhong; Hongrui Guo; Jing Fang

    Ranaviruses are important emerging pathogens of ectothermic vertebrates that threaten aquaculture and wildlife worldwide. A mortality event occurred in a cultured population of catfish‐like loach (Triplophysa siluorides) in Sichuan Province, China. Gross clinical signs of the affected fish included skin lesions and haemorrhagic ulcers, which are often associated with ranaviruses. Inoculation of liver, kidney and spleen tissue homogenates in epithelioma papulosum cyprini (EPC) cells at 25°C resulted in cytopathic effect within 24 hr. Transmission electron microscopy of infected EPC cells revealed hexagonal viral arrays in the cytoplasm and icosahedral geometry of the virions. Following exposure of T. siluroides to the isolated virus, similar clinical signs were observed and the fish experienced 40% and 90% mortality after 21 days at 103.58 and 107.8 TCID50/0.1 ml doses, respectively, providing evidence the isolated virus was the main causative agent of the mortality event. Diagnostic PCR of the major capsid protein gene of ranavirus showed that all samples of diseased fish and isolated virus were positive. Phylogenetic analysis revealed that the isolated virus, designated as FYLl40220, was associated with the Common Midwife Toad Virus (CMTV)‐like ranavirus clade. To our knowledge, this case represents the first report of CMTV‐associated mortality in a fish species. Collectively, these results suggest that the host range of CMTV‐like ranaviruses is greater than previously thought, and this clade of ranaviruses could have significant economic and biodiversity impacts.

    更新日期:2020-01-14
  • Wild griffon vultures (Gyps fulvus) fed at supplementary feeding stations: Potential carriers of pig pathogens and pig‐derived antimicrobial resistance?
    Transbound. Emerg. Dis. (IF 3.554) Pub Date : 2020-01-13
    Eloísa Sevilla; Clara Marín; José F. Delgado‐Blas; Bruno González‐Zorn; Santiago Vega; Ed Kuijper; Rosa Bolea; Raúl C. Mainar‐Jaime

    The carriage of two important pathogens of pigs, that is enterotoxigenic Escherichia coli (ETEC) and Clostridioides difficile, was investigated in 104 cloacal samples from wild griffon vultures (Gyps fulvus) fed on pig carcasses at supplementary feeding stations (SFS), along with their level of antimicrobial resistance (AMR). E. coli was isolated from 90 (86.5%) samples, but no ETEC was detected, likely because ETEC fimbriae confer the species specificity of the pathogen. Resistance to at least one antimicrobial agent was detected in 89.9% of E. coli isolates, with AMR levels being extremely high (>70%) for tetracycline and streptomycin and very high (>50%) for ampicillin and sulfamethoxazole–trimethoprim. Resistance to other critically important antimicrobials such as colistin and extended‐spectrum cephalosporins was 2.2% and 1.1%, respectively, and was encoded by the mcr‐1 and blaSHV‐12 genes. Multidrug resistance was displayed by 80% of the resistant E. coli, and blaSHV‐12 gene shared plasmid with other AMR genes. In general, resistance patterns in E. coli from vultures mirrored those found in pigs. Clostridioides difficile was detected in three samples (2.9%); two of them belonged to PCR ribotype 078 and one to PCR ribotype 126, both commonly found in pigs. All C. difficile isolates were characterized by a moderate‐to‐high level of resistance to fluoroquinolones and macrolides but susceptible to metronidazole or vancomycin, similar to what is usually found in C. difficile isolates from pigs. Thus, vultures may contribute somewhat to the environmental dissemination of some pig pathogens through their acquisition from pig carcasses and, more importantly, of AMR for antibiotics of critical importance for humans. However, the role of vultures would likely be much lesser than that of disposing pig carcasses at the SFS. The monitoring of AMR, and particularly of colistin‐resistant and ESBL‐producing E. coli, should be considered in pig farms used as sources of carcasses for SFS.

    更新日期:2020-01-14
  • Fatal canine parvovirus‐2 (CPV‐2) infection in a rescued free‐ranging Taiwanese pangolin (Manis pentadactyla pentadactyla)
    Transbound. Emerg. Dis. (IF 3.554) Pub Date : 2020-01-11
    Sin‐Ling Wang; Yang‐Chang Tu; Ming‐Shiuh Lee; Li‐Hsin Wu; Ting‐Yu Chen; Chieh‐Hao Wu; Eric Hsien‐Shao Tsao; Shih‐Chien Chin; Wen‐Ta Li

    Carnivore protoparvovirus 1 includes feline parvovirus (FPV), variants of canine parvovirus‐2 (CPV‐2), mink enteritis virus, and raccoon parvovirus, important pathogens affecting both wild and domestic carnivores. In this report, we described a fatal CPV‐2 infection in a rescued Taiwanese pangolin, which provides the first evidence of CPV‐2 infection in a non‐carnivore. Post‐rescue, the Taiwanese pangolin died from complications resulting from a severe panleucocytopenia and bloody diarrhoea. A full autopsy was performed and microscopic examination of the tissues revealed ulcerative, necrotizing, and haemorrhagic glossitis, esophagitis and enteritis. The results of transmission electronic microscopy, polymerase chain reaction and in situ hybridization provided confirmatory evidence that the lesions in the tongue, oesophagus and intestine were associated with a protoparvovirus. Phylogenetic comparison of the whole VP2 gene from the current pangolin protoparvovirus strain showed close clustering with the CPV‐2c strains from domestic dogs in Taiwan, China and Singapore. The amino acid sequence of the pangolin protoparvovirus showed 100% identity to the CPV‐2c strains from domestic dogs in China, Italy, and Singapore. The current findings highlight that pangolins are susceptible to protoparvoviruses. The potential of cross‐species transmission of protoparvoviruses between Carnivora and Pholidota should be considered when housing pangolins in close proximity to carnivores and adopting strict biosecurity measures to avoid cross‐species transmission in rescue facilities and zoos.

    更新日期:2020-01-13
  • Immunohistochemical identification of antigens of canine distemper virus in neotropical felids from Southern Brazil
    Transbound. Emerg. Dis. (IF 3.554) Pub Date : 2020-01-09
    Nayara Emily Viana; Mariana de Mello Zanim Michelazzo; Thalita Evani Silva Oliveira; Zalmir Silvino Cubas; Wanderlei de Moraes; Selwyn Arlington Headley

    The pathologic and immunohistochemical findings associated with infections due to canine distemper virus (CDV) are described in the cougar (Puma concolor), margay (Leopardus wiedii) and jaguarundi (Herpailurus yagouaroundi) from Southern Brazil. Tissue sections of the neotropical felids (n = 3) that died at the Bela Vista Sanctuary, Paraná, Southern Brazil were routinely processed for histopathology to identify possible histopathologic patterns associated with infections due to CDV. Selected formalin‐fixed paraffin embedded tissue sections of the lungs and urinary bladder were used in immunohistochemical assays designed to identify the antigens of CDV. The main histopathologic patterns identified were interstitial pneumonia in the margay and jaguarundi, while ballooning degeneration of the transitional epithelium of the urinary bladder was observed in the cougar. Positive immunoreactivity to antigens of CDV was identified within intralesional sections of the lungs of the two wild felids with interstitial pneumonia and in the degenerated urothelium of the cougar. These findings indicate that these neotropical cats were infected by a viral infectious disease pathogen common to the domestic dog and add to the few documented descriptions of CDV‐induced infections in wildlife from Brazil.

    更新日期:2020-01-09
  • Multilayer network analysis unravels haulage vehicles as a hidden threat to the British swine industry
    Transbound. Emerg. Dis. (IF 3.554) Pub Date : 2020-01-08
    Thibaud Porphyre; Barend M. de C. Bronsvoort; George J. Gunn; Carla Correia‐Gomes

    When assessing the role of live animal trade networks in the spread of infectious diseases in livestock, attention has focused mainly on direct movements of animals between premises, whereas the role of haulage vehicles used during transport, an indirect route for disease transmission, has largely been ignored. Here, we have assessed the impact of sharing haulage vehicles from livestock transport service providers on the connectivity between farms as well as on the spread of swine infectious diseases in Great Britain (GB). Using all pig movement records between April 2012 and March 2014 in GB, we built a series of directed and weighted static multiplex networks consisting of two layers of identical nodes, where nodes (farms) are linked either by (a) the direct movement of pigs and (b) the shared use of haulage vehicles. The haulage contact definition integrates the date of the move and the duration that lorries are left contaminated by pathogens, hence accounting for the temporal aspect of contact events. For increasing , descriptive network analyses were performed to assess the role of haulage on network connectivity. We then explored how viruses may spread throughout the GB pig sector by computing the reproduction number Our results showed that sharing haulage vehicles increases the number of contacts between farms by >50% and represents an important driver of disease transmission. In particular, sharing haulage vehicles, even if  < 1 day, will limit the benefit of the standstill regulation, increase the number of premises that could be infected in an outbreak, and more easily raise above 1. This work confirms that sharing haulage vehicles has significant potential for spreading infectious diseases within the pig sector. The cleansing and disinfection process of haulage vehicles is therefore a critical control point for disease transmission risk mitigation.

    更新日期:2020-01-09
  • Phylogenetic profiling for zoonotic Ehrlichia spp. from ixodid ticks in the Eastern Cape, South Africa
    Transbound. Emerg. Dis. (IF 3.554) Pub Date : 2020-01-08
    Olusesan Adeyemi Adelabu; Benson Chuks Iweriebor; Anthony Ifeanyi Okoh; Larry Chikwelu Obi

    Ticks are obligate hematophagous parasite of vertebrate that transmit a range of pathogenic microorganisms that can cause diseases in livestock and humans. The range of tick‐borne disease causative agents infecting domestic animals and humans has recently increased. Several significant zoonotic tick‐borne diseases such as ehrlichiosis among others are on the increase worldwide. This study was designed to investigate the occurrence of zoonotic Ehrlichia spp. from samples collected from livestock in selected communities in the Eastern Cape Province, South Africa. Tick samples were manually collected from domesticated animals in selected homesteads. The ticks were morphologically identified to species and tested for Ehrlichia infection via polymerase chain reaction (PCR), using genus‐specific disulphide bond formation protein (dsbA) gene primers. This was followed by sequence analysis of amplicons and phylogeny. Of the 1,200 ticks collected, Amblyomma hebraeum was most prevalent (n = 335; 27.9%), followed by Rhipicephalus appendiculatus (n = 274; 22.8%), Rhipicephalus decoloratus; (n = 224; 18.7%) and Rhipicephalus eversti eversti (n = 200, 16.7%). Ehrlichia DNA was detected in 19/1,200 (1.6%) of the screened DNA samples. A homology search of the generated sequences revealed a high percentage of identity between 95% and 98% with other homologous dsbA gene sequences of other Ehrlichia species in GenBank. Phylogenetic analysis showed that the obtained sequences clustered unambiguously with other Ehrlichia sequences from different geographical regions of the world. We concluded that Ehrlichial pathogens are vectored by the ticks collected from domesticated animals in the study areas, thus suggesting concern for public health, as some of the recovered pathogens are zoonotic in nature and could pose serious public health risk through human exposure to tick bites.

    更新日期:2020-01-09
  • Leishmania sp. detection and blood‐feeding behaviour of Sergentomyia minuta collected in the human leishmaniasis focus of southwestern Madrid, Spain (2012–2017)
    Transbound. Emerg. Dis. (IF 3.554) Pub Date : 2020-01-08
    Estela González; Ricardo Molina; Irene Aldea; Andrés Iriso; Ana Tello; Maribel Jiménez

    Phlebotomine sand flies are the only known vectors of Leishmania spp. protozoan which causes leishmaniasis in 98 countries. In Spain, 11 sand fly species are described, but only Phlebotomus perniciosus and Phlebotomus ariasi are proven vectors of the disease. On the other hand, Sergentomyia minuta is one of the most abundant and ubiquitous sand flies in this territory, although scarce information is available about this species. Sand flies from this genus are known for their preference to feed on cold‐blooded animals and are traditionally involved in the transmission of reptile Leishmania. However, studies have suggested that Sergentomyia spp. could be implicated in the transmission of human pathogenic Leishmania. This study analyses blood meal preferences and Leishmania sp. infection of S. minuta sand flies from the largest human leishmaniasis outbreak in Europe. Sand flies were collected during entomological surveillance carries out from 2012 to 2017 in the active season of these dipterans, from May to October. Molecular detection of Leishmania spp. showed 68 positive specimens of S. minuta out of 377 (18%). The analysis of blood meal preferences by amplification of 359 bp fragment of cytochrome b gene revealed that blood preference of S. minuta is not only limited to reptiles, but they also feed on mammals, including humans. Results suggest the presence of a Leishmania sp., related to Leishmania tarentolae, cycle in S. minuta from the studied area. Although there is no evidence about its incrimination in the L. infantum transmission more investigation is needed to elucidate the intravectorial cycle of Leishmania spp. in S. minuta sand flies, their feeding behaviour and their potential contribution in Leishmania spp. epidemiology in the country.

    更新日期:2020-01-09
  • Clinical cases of Bluetongue serotype 8 in calves in France in the 2018–2019 winter
    Transbound. Emerg. Dis. (IF 3.554) Pub Date : 2020-01-08
    Chloé Vinomack; Julie Rivière; Emmanuel Bréard; Cyril Viarouge; Lydie Postic; Stéphan Zientara; Damien Vitour; Guillaume Belbis; Vincent Spony; Caroline Pagneux; Corinne Sailleau; Gina Zanella

    Bluetongue virus serotype 8 (BTV‐8) caused an epizootic in Europe in 2006/09. Transplacental transmission of BTV‐8 was demonstrated leading to abortions, congenital malformations or nervous clinical signs in newborn calves. BTV‐8 re‐emerged in France in 2015. Although the re‐emergent strain is nearly genetically identical to the one that had circulated in 2006/2009, it has caused very few clinical cases. However, from mid‐December 2018 to April 2019, cases of calves with congenital malformations or displaying nervous clinical signs occurred in some departments (French administrative unit) in mainland France. Blood samples from these animals were sent to local laboratories, and the positive ones were confirmed at the French Bluetongue reference laboratory (BT‐NRL). Out of 580 samples found positive at the local laboratories, 544 were confirmed as RT‐PCR BTV‐8 positive. The 36 samples found positive in the local laboratories and negative in the BT‐NRL were all at the limit of RT‐PCR detection. Hundred eighty‐eight of the confirmed samples were also tested for the presence of Schmallenberg virus (SBV) and bovine virus diarrhoea virus (BVDV) infection: 4 were found positive for BVDV and none for SBV. The main clinical signs recorded for 244 calves, for which a reporting form was completed by veterinarians, included nervous clinical signs (81%), amaurosis (72%) and decrease/ no suckling reflex (40%). Hydranencephaly and microphthalmia were reported in 19 calves out of 27 in which a necropsy was practiced after death or euthanasia. These results indicate that the re‐emergent strain of BTV‐8 can cross the transplacental barrier and cause congenital malformations or nervous clinical signs in calves.

    更新日期:2020-01-09
  • Characterization of transboundary foot‐and‐mouth disease viruses in Nigeria and Cameroon during 2016
    Transbound. Emerg. Dis. (IF 3.554) Pub Date : 2020-01-07
    David Odion Ehizibolo; Ian H. Fish; Barbara Brito; Miranda R. Bertram; Abdullahi Ardo; Hussaini G. Ularamu; David D. Lazarus; Yiltawe S. Wungak; Chika I. Nwosuh; George R. Smoliga; Ethan J. Hartwig; Steven James Pauszek; Simon Dickmu; Souley Abdoulkadiri; Jonathan Arzt

    Continuous surveillance for foot‐and‐mouth disease (FMD) in endemic settings such as West Africa is imperative to support improved local and regional control plans, with the long‐term goal of regional eradication. This paper describes the genetic characterization of FMD viruses (FMDV) obtained from outbreaks in Nigeria (n = 45) and Cameroon (n = 15) during 2016 and from archival samples (n = 3) retrieved from a 2014 outbreak in Nigeria. These viruses were analysed in the context of previously published FMDV sequences from the region. Four FMDV serotypes: O, A, SAT1 and SAT2, were detected. Phylogenetic analyses of the VP1 coding sequences indicate the continuity of FMDV serotype O East Africa‐3 (O/EA‐3), serotype A AFRICA genotype G‐IV (A/AFRICA/G‐IV) and serotype South African Territories (SAT) 2 lineage VII (SAT2/VII). The FMDV SAT1 topotype X (SAT1/X), which emerged in Nigeria in 2015, continued to be associated with outbreaks in the region during 2016, and SAT1 is reported for the first time from Cameroon. Additionally, a re‐emergence or re‐introduction of the serotype O West Africa (O/WA) topotype in Nigeria is described herein. Our findings indicate a consistent, pan‐serotypic relationship between FMDV strains detected in Cameroon and Nigeria. Additionally, FMDV strains from West Africa obtained in this study were genetically related to those occurring in East and North Africa. These phylogenetic relationships suggest that animal movements (pastoralism and/or trade) are important factors for virus spread across the African continent. These data provide critical baselines which are a necessary component of Stages 0 and 1 of the Progressive Control Pathway of FMD (PCP‐FMD). Specifically, characterizing the existing virus strains (risk) provides the basis for the comprehensive risk‐based control plan which is the requisite criteria for Nigeria's transition to Stage 2 of PCP‐FMD, and for coordinated regional control of FMD.

    更新日期:2020-01-07
  • Detection and genetic characterization of porcine circovirus 3 (PCV3) in pigs in India
    Transbound. Emerg. Dis. (IF 3.554) Pub Date : 2020-01-07
    Bidhan Chandra Bera; Mamta Choudhary; Taruna Anand; Nitin Virmani; Karthik Sundaram; Binod Choudhary; Bhupendra Nath Tripathi

    Porcine circovirus type 3 (PCV3), a novel circovirus, has been reported recently from major swine growing countries globally, and the virus is associated with diseases like porcine dermatitis, nephropathy syndrome and reproductive failure. This report describes the identification of PCV3 associated with reproductive failure in sows and piglet mortality and circulation of the virus in healthy pigs in India. The pathological changes in various tissues from stillborn piglet and characterization of the virus genomes were reported. The genome sequences of Indian PCV3 strains showed 91.4%–99.8% nucleotide identity with other sequences of PCV3 strains circulating worldwide. The phylogenetic analysis showed clustering of Indian strains into a separate group with the isolate from USA (MN/2016) under PCV3a genotype. The results confirmed the circulation of PCV3 in Indian pigs and its association with clinical cases. This study speculates emergence of PCV3 as an important pig pathogen in the country, which warrants the thorough investigation on PCV3 epidemiology, pathogenesis and to implement the control measures.

    更新日期:2020-01-07
  • Seasonal and spatial variation in Culicoides community structure and their potential role in transmitting Simbu serogroup viruses in Israel
    Transbound. Emerg. Dis. (IF 3.554) Pub Date : 2020-01-03
    Adi Behar; Asael Rot; Yaniv Lavon; Omer Izhaki; Nadav Gur; Jacob Brenner

    Culicoides biting midges (Diptera: Ceratopogonidae) are a successful group of small (1–3 mm) haematophagous flies, some species of which are biological vectors of veterinary arboviruses, such as bluetongue virus, epizootic haemorrhagic disease virus, African horse sickness virus and Simbu serogroup viruses. In this study, we examine seasonal and spatial effects on the presence and distribution of Culicoides communities associated with ruminant and equine farms in Israel, and their infection with Simbu serogroup viruses. Our results demonstrate that both the vectors and the viruses are widely spread in Israel, including regions that were previously considered Culicoides‐free. Moreover, our results show that although seasonality affects infection with Simbu serogroup viruses, both viruses and potential vectors can be found year round, suggesting continuous circulation of Simbu serogroup viruses in Israeli livestock farms. Finally, this study provides novel and basic information on Simbu serogroup‐infected Culicoides in Israel: it demonstrates that Sathuperi, Shuni and Peaton viruses were circulating in Israel in 2015–2017 as they were found in C. imicola and C. oxystoma, both potential vectors of these viruses, and supplies the first‐ever genomic detection of Sathuperi in Israel. Consequently, the data emerging from this study are of importance in understanding the epidemiology of arboviruses in Israel and are of relevance to the potential spread and possible future outbreaks of different Simbu serogroup viruses within the Mediterranean region and Europe.

    更新日期:2020-01-04
  • Molecular characteristics of the re‐emerged avian leukosis virus in China, 2018–2019
    Transbound. Emerg. Dis. (IF 3.554) Pub Date : 2020-01-03
    Yawen Zhang; Qi Su; Zhihui Zhang; Zhizhong Cui; Shuang Chang; Peng Zhao

    Since early 2018, avian leukosis virus (ALV) has re‐emerged throughout six provinces in Northeast and East of China and caused huge economic losses. In different farms, there are significant differences in clinical symptoms, including morbidity, mortality and location of tumours, on affected animals, which implies that the present strains may have different origins and molecular characteristics. In this study, a systematic epidemiological investigation was conducted in 21 farms in six provinces. Results showed that the virus strains present in this outbreak are highly consistent but carry different mutations. All the strains shared 97.0%–99.0% identity with each other and were highly similar to the GD14J2 strain isolated previously, while different insertion fragments can be found in the env gene of different strains, suggesting that the strains of ALV in this outbreak may have the same ancestors but have gone through different evolutionary trajectories. This study demonstrated that these viruses may point to multiple sources of infection, and all should be identified and taken seriously in the formulation of control plans.

    更新日期:2020-01-04
  • Assessing the health risks of reintroduction: The example of the Amur leopard, Panthera pardus orientalis
    Transbound. Emerg. Dis. (IF 3.554) Pub Date : 2019-12-29
    John Lewis; Alex Tomlinson; Martin Gilbert; Mikhail Alshinetski; Tanya Arzhanova; Mikhail Goncharuk; John Goodrich; Linda Kerley; Irina Korotkova; Dale Miquelle; Sergey Naidenko; Nadezhda Sulikhan; Olga Uphyrkina

    Translocation of wildlife as a means of reintroducing or reinforcing threatened populations is an important conservation tool but carries health risks for the translocated animals and their progeny, as well as wildlife, domestic animals and humans in the release area. Disease risk analyses (DRA) are used to identify, prioritize and design mitigation strategies to address these threats. Here, we use a DRA undertaken for Amur leopards (Panthera pardus orientalis) to illustrate how specific methodology can optimize mitigation strategy design. A literature review identified a total of 98 infectious hazards and 28 non‐infectious hazards. Separate analyses were undertaken for disease risks in leopards from hazards of source origin (captive zoo collections and the transit pathway to the Russian Far East), or of destination origin (in breeding enclosures and wider release areas); and for disease risks in other wildlife, domesticated species or humans, similarly from hazards of source or destination origin. Hazards were assessed and ranked as priority 1, priority 2, priority 3 or low priority in each of the defined scenarios. In addition, we undertook a generic assessment of stress on individual leopards. We use three examples to illustrate the process: Chlamydophila felis, canine distemper virus (CDV) and feline immunodeficiency virus (FIV). We found that many potentially expensive screening procedures could be performed prior to export of leopards, putting the onus of responsibility onto the zoo sector, for which access to diagnostic testing facilities is likely to be optimal. We discuss how our methods highlighted significant data gaps relating to pathogen prevalence in the Russian Far East and likely future unpredictability, in particular with respect to CDV. There was emphasis at all stages on record keeping, meticulous planning, design, staff training and enclosure management, which are relatively financially inexpensive. Actions to minimize stress featured at all time points in the strategy and also focussed on planning, design and management.

    更新日期:2019-12-30
  • Analysis of Theileria equi diversity in The Gambia using a novel genotyping method
    Transbound. Emerg. Dis. (IF 3.554) Pub Date : 2019-12-29
    Robert M. Coultous; Michael McDonald; Alexandra G. Raftery; Brian R. Shiels; David G. M. Sutton; William Weir

    Theileria equi, one of the primary pathogens causing equine piroplasmosis, has previously been sub‐classified into a number of clades on the basis of 18S SSU rRNA gene sequence diversity. This partitioning of the parasite population has potential implications for host immunity, treatment and vaccine development. To detect and identify different clade genotypes among and within individual equine blood samples, a novel PCR‐based technique was designed and optimized. Theileria equi has only recently been described in The Gambia, and the developed genotyping technique was used to analyse blood samples taken from 42 piroplasmosis‐positive horses and donkeys within the country. Three different T. equi genotypes were detected within the population, including the same genotype as the recently described Theileria haneyi, with 61.9% of individuals found to be infected with more than one genotype. Overall, there was a trend that males were more likely to have a multiple genotype infection. Thus, the novel genotyping technique has been shown to be effective in analysis of field populations and offers researchers a rapid method of identifying multiple T. equi genotypes both within individuals and equine populations in epidemiological studies.

    更新日期:2019-12-29
  • Origin and global spreading of an ancestral lineage of the infectious bursal disease virus
    Transbound. Emerg. Dis. (IF 3.554) Pub Date : 2019-12-27
    Gonzalo Tomás; Ana Marandino; Claudia Techera; Valeria Olivera; Paula Perbolianachis; Eddie Fuques; Sofía Grecco; Martín Hernández; Diego Hernández; Lucía Calleros; María Isabel Craig; Yanina Panzera; Ariel Vagnozzi; Ruben Pérez

    Infectious bursal disease virus (IBDV) is an economically relevant and widespread pathogen that produces immunosuppression in young chickens. IBDV is genetically classified into seven genogroups (G1–G7), where the traditional classic, variant and very virulent strains correspond to G1, G2 and G3, respectively. The G4 strains, also known as ‘distinct’ (dIBDV), have recently acquired increased relevance because of their prevalence and notorious impair to the poultry industry in South America. Here, worldwide dIBDV strains were studied using phylogenetic and phylodynamic approaches. The phylogenetic analyses performed using partial and complete sequences of both viral segments (A and B) consistently clustered the dIBDV strains in a monophyletic group. The analyses of the VP5, polyprotein and VP1 coding regions identified amino acid residues that act as markers for the identification of the entire dIBDV group or different sub‐populations. The phylodynamic analyses performed using the hypervariable region of VP2 indicated that the dIBDV strains emerged in the early 1930s in Eastern Europe, shortly after the emergence of classic strains (1927) and before variant (1949) and very virulent strains (1967). The analysis of the migration routes indicated that after its emergence, the dIBDV strains spread to Eastern Asia around 1959, to Brazil around 1963, and to Argentina around 1990. These inter‐continental migrations resulted in three sub‐populations that are currently represented by strains from (a) Brazil, (b) Eastern Asia and Canada, and (c) Eastern Europe, Argentina and Uruguay. Taken together, our results highlight the complex evolutionary history of IBDV and the importance of new phylodynamic data to unravel and nearly follow the different evolutionary pathways taken by this important poultry pathogen.

    更新日期:2019-12-29
  • Molecular epidemiology of peste des petits ruminants in Niger: An update
    Transbound. Emerg. Dis. (IF 3.554) Pub Date : 2019-12-27
    Maman Moutari Souley; Abdoulkarim Issa Ibrahim; Djibo Sidikou; William G. Dundon; Giovanni Cattoli; Alassane Abdou; Fati Soumana; Bachir Yaou

    Like many West African countries, outbreaks of peste des petits ruminants (PPR), an economically important disease of goats and sheep, are regularly reported in Niger. The causative virus, peste des petits ruminants virus (PPRV), can be differentiated into four genetically distinct lineages. A publication in 2018 identified three PPRV lineages circulating in the country in 2001 (lineages I and II) and 2013 (lineage IV), respectively. In this present study, more recent samples were collected from goats and sheep in locations throughout Niger between 2011 and 2017. Twelve PPRV‐positive samples were characterized by sequencing of a segment of the nucleocapsid protein (N) gene. Phylogenetic analysis of the sequences identified viruses from lineages II and IV only. The analysis also indicated a shared origin of the viruses from Niger with PPRVs from neighbouring countries suggesting transboundary movement.

    更新日期:2019-12-29
  • In silico identification of immunotherapeutic and diagnostic targets in the glycosylphosphatidylinositol metabolism of the coccidian Sarcocystis aucheniae
    Transbound. Emerg. Dis. (IF 3.554) Pub Date : 2019-12-27
    Cecilia Decker Franco; Sarah N. Wieser; Marcelo Soria; Paloma de Alba; Mónica Florin‐Christensen; Leonhard Schnittger

    Meat of the South American camelids (SACs) llama and alpaca is an important source of animal protein and income for rural families in the Andes, and a product with significant growth potential for local and international markets. However, infestation with macroscopic cysts of the coccidian protozoon Sarcocystis aucheniae, a parasitosis known as SAC sarcocystosis, significantly hampers its commercialization. There are no validated methods to diagnose the presence of S. aucheniae cysts other than carcass examination. Moreover, there are no available drugs or vaccines to cure or prevent SAC sarcocystosis. Identification of relevant molecules that act at the host–pathogen interface can significantly contribute to the control of this disease. It has been shown for other pathogenic protozoa that glycosylphosphatidylinositol (GPI) is a critical molecule implicated in parasite survival and pathogenicity. This study focused on the identification of the enzymes that participate in the S. aucheniae GPI biosynthetic pathway and the repertoire of the parasite GPI‐anchored proteins (GPI‐APs). To this aim, RNA was extracted from parasite cysts and the transcriptome was sequenced and translated into amino acid sequences. The generated database was mined using sequences of well‐characterized GPI biosynthetic enzymes of Saccharomyces cerevisiae and Toxoplasma gondii. Eleven enzymes predicted to participate in the S. aucheniae GPI biosynthetic pathway were identified. On the other hand, the database was searched for proteins carrying an N‐terminal signal peptide and a single C‐terminal transmembrane region containing a GPI anchor signal. Twenty‐four GPI‐anchored peptides were identified, of which nine are likely S. aucheniae‐specific, and 15 are homologous to membrane proteins of other coccidians. Among the latter, 13 belong to the SRS domain superfamily, an extensive group of coccidian GPI‐anchored proteins that mediate parasite interaction with their host. Phylogenetic analysis showed a great degree of intra‐ and inter‐specific divergence among SRS family proteins. In vitro and in vivo experiments are needed to validate S. aucheniae GPI biosynthetic enzymes and GPI‐APs as drug targets and/or as vaccine or diagnostic antigens.

    更新日期:2019-12-27
  • Highly sensitive nested PCR and rapid immunochromatographic detection of Babesia bovis and Babesia bigemina infection in a cattle herd with acute clinical and fatal cases in Argentina
    Transbound. Emerg. Dis. (IF 3.554) Pub Date : 2019-12-27
    Sabrina Ganzinelli; Daniel Benitez; Sambuu Gantuya; Azirwan Guswanto; Monica Florin‐Christensen; Leonhard Schnittger; Ikuo Igarashi

    Bovine babesiosis is a tick‐transmitted haemoparasitic disease caused by Babesia bovis and B. bigemina affecting cattle of tropical and subtropical regions around the world. Pathogens are transmitted by the tick vector Rhipicephalus microplus displaying a widespread distribution in northeastern Argentina. The disease is characterized by significant animal morbidity and mortality resulting in considerable economic loss. In this study, B. bovis and B. bigemina infection was investigated in a cattle herd of 150 adult bovines of pure Braford breed raised in a tick‐hyperendemic field using molecular and serum antibody tests. A highly sensitive nested polymerase chain reaction (nPCR) assay targeting a species‐specific region of the apocytochrome b gene resulted in direct B. bovis and B. bigemina detection in 27.3% and 54.7% of bovines, respectively. A recently developed immunochromatographic strip test (ICT) based on recombinant forms of spherical body protein 4 and the C‐terminal region of rhoptry‐associated protein 1 showed that 71.3% and 89.3% of bovines were seropositive for B. bovis and B. bigemina, respectively. The mixed infection rate as observed by direct (19.3%) and indirect detection (65.3%) coincided with those expected, respectively. Importantly, four months after sampling, nine bovines of the studied herd showed clinical signs of bovine babesiosis of which six animals eventually died. Microscopic detection of infected erythrocytes in Giemsa‐stained blood smears confirmed B. bovis infection. Our study demonstrates that although animals showed a relatively high and very high rate of immunity against infection with B. bovis (71.3%) and B. bigemina (89.3%) parasites, respectively, clinical cases and fatalities due to the infection with B. bovis were observed. It is proposed that the most adequate control measure in the studied epidemiological situation is to vaccinate animals to prevent losses and/or an outbreak of bovine babesiosis.

    更新日期:2019-12-27
  • Hantavirus antibodies among phyllostomid bats from the arc of deforestation in Southern Amazonia, Brazil
    Transbound. Emerg. Dis. (IF 3.554) Pub Date : 2019-12-27
    Gilberto Sabino‐Santos; Francimeire Fernandes Ferreira; David José Ferreira da Silva; Danilo Melo Machado; Sergio Gomes da Silva; Christine Steiner São Bernardo; Manoel dos Santos Filho; Taal Levi; Luiz Tadeu Moraes Figueiredo; Carlos A. Peres; Roberta Vieira de Morais Bronzoni; Gustavo Rodrigues Canale

    In order to determine whether southern Amazonian bats could harbour hantaviruses we, serologically and molecularly, screened blood, saliva, excreta and organ tissues of 47 bats captured from September to December 2015. We found that only phyllostomid bats presented antibodies against hantavirus. The seropositive bats belonged to two species of Phyllostomid bats: the greater spear‐nosed bat Phyllostomus hastatus (omnivorous) and the gnome fruit‐eating bat Dermanura gnoma. The overall seroprevalence was of 4.2%. Therefore, we show here that hantaviruses are circulating among phyllostomid bats in the Amazonian arc of deforestation.

    更新日期:2019-12-27
  • Identification and molecular characterization of Staphylococcus aureus and multi‐drug resistant MRSA from monkey faeces in China
    Transbound. Emerg. Dis. (IF 3.554) Pub Date : 2019-12-26
    Yang Li; Yuanyue Tang; Jingwei Ren; Jinlin Huang; Qiuchun Li; Hanne Ingmer; Xinan Jiao

    Staphylococcus aureus is a commensal bacterium and an important opportunistic pathogen in humans and animals. The increase in multi‐drug resistant (MDR) strains of S. aureus is a growing concern due to their impact on animal health and potential for zoonotic transmission. Increasing evidence has shown that MRSA could be transmitted by faeces. The present study determined the prevalence, antibiotic resistance profile and genotypic characteristics of S. aureus isolated from monkey faecal samples in China. Thirty‐eight out of 145 (26.21%) macaque faecal samples were S. aureus positive, which eight (5.5%) isolates were identified as MRSA. Antimicrobial susceptibility tests showed that most of the S. aureus isolates were resistant to tetracycline (TE, 44.74%), followed by penicillin (P, 21.05%), cefoxitin (FOX, 21.05%) and ciprofloxacin (CIP, 18.42%). The predominant spa types were t13638 (44.74%) and t189 (13.16%), which are reported to be closely associated with human infections in China. All MRSA isolates belonged to the SCCmecV type, which six of MRSA isolates were ST3268, while the other two isolates belonged to ST4981. This study for the first time describes the prevalence of S. aureus and MRSA in monkey faeces in China, indicating that faeces could be a potential factor of transmitting S. aureus between humans and monkeys.

    更新日期:2019-12-27
  • Novel circovirus species identified in farmed pigs designated as Porcine circovirus 4, Hunan province, China
    Transbound. Emerg. Dis. (IF 3.554) Pub Date : 2019-12-24
    Hui‐Hui Zhang; Wen‐Qin Hu; Jie‐Yu Li; Tian‐Ning Liu; Ji‐Yong Zhou; Tanja Opriessnig; Chao‐Ting Xiao

    In pigs, three circovirus species within the genus Circovirus have been identified so far, including the non‐pathogenic Porcine circovirus 1 (PCV1), the pathogenic Porcine circovirus 2 (PCV2) and the recently identified Porcine circovirus 3 (PCV3). In April 2019, a new circovirus with a distinct relationship to other circoviruses was identified in several pigs with severe clinical disease in Hunan province, China. The size of the viral genome, tentatively designated as porcine circovirus type 4 (PCV4), is 1,770 nucleotides (nt). PCV4 shows the highest genomic identity to mink circovirus (66.9%) and has identities of 43.2%–51.5% to the other PCV genomes. Two major genes, a replicase (Rep) gene spanning 891 nt and a capsid (Cap) gene spanning 687 nt, were predicted. Furthermore, a TaqMan® real‐time polymerase chain reaction (PCR) targeting the replicase gene was developed to investigate the prevalence of PCV4 in 187 clinical samples from Hunan province, China. The results revealed an overall PCV4 prevalence of 12.8%, with the highest positive rates in nasal swabs (28.5%, 6/21) followed by serum samples (13.4%, 11/82). The clinical significance and pathogenesis of this virus needs further investigation.

    更新日期:2019-12-25
  • Emergence of West Nile virus lineage 2 in Europe: Characteristics of the first seven cases of West Nile neuroinvasive disease in horses in Austria
    Transbound. Emerg. Dis. (IF 3.554) Pub Date : 2019-12-24
    Phebe de Heus; Jolanta Kolodziejek; Jeremy V. Camp; Katharina Dimmel; Zoltán Bagó; Zdenek Hubálek; René van den Hoven; Jessika‐M. V. Cavalleri; Norbert Nowotny

    We report details of the first seven equine cases of confirmed West Nile neuroinvasive disease in Austria. The cases presented during summer and autumn of 2016 (n = 2), 2017 (n = 3) and 2018 (n = 2). All horses showed gait abnormalities and 6 of 7 horses exhibited fasciculations and/or tremors, and we provide video recordings of these. Three horses also showed cranial nerve involvement. Following rapid improvement, three horses were discharged. Four horses were euthanized due to the severity of clinical signs and subjected to neuropathological examination. West Nile virus (WNV) lineage 2 nucleic acid was detected in 5 of 7 horses, and WNV‐specific neutralizing antibodies in all 7 horses. In addition, serologic evidence of WNV infection was found in two out of fourteen in‐contact horses. Horses may be considered a sentinel species for human WNV infections, integrating human and veterinary medicine and thus contributing to the one health concept.

    更新日期:2019-12-25
  • Evidence for multiple recombination events within foot‐and‐mouth disease viruses circulating in West Eurasia
    Transbound. Emerg. Dis. (IF 3.554) Pub Date : 2019-12-23
    Syed M. Jamal; Mohamad Hossein Nazem Shirazi; Fuat Ozyoruk; Unal Parlak; Preben Normann; Graham J. Belsham

    Phylogenetic studies on foot‐and‐mouth disease viruses (FMDVs) circulating in the West Eurasian region have largely focused on the genomic sequences encoding the structural proteins that determine the serotype. The present study has compared near‐complete genome sequences of FMDVs representative of the viruses that circulate in this region. The near‐complete genome sequences (ca. 7,600 nt) were generated from multiple overlapping RT‐PCR products. These amplicons were from FMDVs belonging to serotypes O, A and Asia‐1, including members of the O‐PanAsia‐II and the A‐Iran05 lineages, and of Group‐II and Group‐VII (Sindh‐08) within serotype Asia‐1, which are currently predominant and widespread in West Eurasia. These new sequences were analysed together with other sequences obtained from GenBank. Comparison of different regions of the FMDVs genomes revealed evidence for multiple, inter‐serotypic, recombination events between FMDVs belonging to the serotypes O, A and Asia‐1. It is concluded from the present study that dramatic changes in virus sequences can occur in the field through recombination between different FMDV genomes. These analyses provide information about the ancestry of the serotype O, A and Asia‐1 FMDVs that are currently circulating within the West Eurasian region.

    更新日期:2019-12-23
  • Outbreaks of Clade 2.3.4.4 H5N8 highly pathogenic avian influenza in 2018 in the northern regions of South Africa were unrelated to those of 2017
    Transbound. Emerg. Dis. (IF 3.554) Pub Date : 2019-12-23
    Celia Abolnik

    Asian‐origin H5N8 highly pathogenic avian influenza (HPAI) viruses of the H5 Goose/Guangdong/96 lineage, clade 2.3.4.4 group B, reached South Africa by June 2017. By the end of that year, 5.4 million layers and broiler chickens died or were culled, with total losses in the poultry industry estimated at US$ 140 million, and thousands of exotic birds in zoological collections, endangered endemic species and backyard poultry and pet birds also perished. The 2017 H5N8 HPAI outbreaks were characterized by two distinct spatial clusters, each associated with specific reassortant viral genotypes. Genotypes 1, 2, 3 and 5 were restricted to the northern regions, spanning the provinces of Limpopo, Gauteng, North West, Mpumalanga, KwaZulu‐Natal and Free State. The second, much larger cluster of outbreaks was in the south, in the Western and Eastern Cape provinces, wherein 2017 and 2018 outbreaks were caused solely by genotype 4. The last confirmed case of H5N8 HPAI in the northern region in 2017 was in early October, and the viruses seemed to disappear over the summer. However, starting in mid‐February 2018, H5N8 HPAI outbreaks resurged in the north. Viruses from two of the eight outbreaks were sequenced, one from an outbreak in quails (Coturnix japonica) in the North West Province, and another from commercial pullets in the Gauteng province. Phylogenetic analysis identified the viruses as a distinct sixth genotype that was most likely a new introduction to South Africa in early 2018.

    更新日期:2019-12-23
  • Assessment of the impact of forestry and leisure activities on wild boar spatial disturbance with a potential application to ASF risk of spread
    Transbound. Emerg. Dis. (IF 3.554) Pub Date : 2019-12-21
    Karine Petit; Charlotte Dunoyer; Claude Fischer; Jean Hars; Eric Baubet; Jorge Ramón López‐Olvera; Sophie Rossi; Eric Collin; Marie‐Frédérique Le Potier; Catherine Belloc; Carole Peroz; Nicolas Rose; Jean‐Pierre Vaillancourt; Claude Saegerman

    In Europe, African swine fever virus (ASFV) is one of the most threatening infectious transboundary diseases of domestic pigs and wild boar. In September 2018, ASF was detected in wild boar in the South of Belgium. France, as a bordering country, is extremely concerned about the ASF situation in Belgium, and an active preparedness is ongoing in the country. One of the questions raised by this situation relates to disturbing activities that may affect wild boar movements and their possible impact on the spread of ASFV. Despite evidence of disturbance related to hunting practices, there is a paucity of information on the impact of forestry and human leisure activities. To assess this impact on wild boar movements, a systematic review was first conducted but very few useful data were obtained. For this reason, an expert elicitation was carried out by the French Agency for Food, Environmental and Occupational Health & Safety in order to deal with this knowledge gap. A total of 30 experts originating from France and adjacent neighbouring countries (Spain, Belgium and Switzerland) were elicited about the relative importance of six factors of spatial disturbance of wild boar (noise, smell, invasion of space, modification of the environment, duration and frequency of the activity). Then, for each factor of disturbance, they were asked about the impact of 16 different commercial forestry and human leisure activities. A global weighted score was estimated in order to capture the variability of a wide range of territorial conditions and the uncertainty of expert elicitation. This estimate permitted ranking all 16 activities and aggregating them in three groups according to their potential for disturbance of wild boar, using a regression tree analysis. The results of this expert elicitation provide a methodological approach that may be useful for French and other European decision makers and stakeholders involved in the crisis management of ASF.

    更新日期:2019-12-21
  • Network analysis of pig movements in Argentina: Identification of key farms in the spread of infectious diseases and their biosecurity levels
    Transbound. Emerg. Dis. (IF 3.554) Pub Date : 2019-12-20
    Laura V. Alarcón; Pablo A. Cipriotti; Mariela Monterubbianessi; Carlos Perfumo; Enric Mateu; Alberto Allepuz

    This study uses network analysis to evaluate how swine movements in Argentina could contribute to disease spread. Movement data for the 2014–2017 period were obtained from Argentina's online livestock traceability registry and categorized as follows: animals of high genetic value sent to other farms, animals to or from markets, animals sent to finisher operations and slaughterhouse. A network analysis was carried out considering the first three movement types. First, descriptive, centrality and cohesion measures were calculated for each movement type and year. Next, to determine whether networks had a small‐world topology, these were compared with the results from random Erdös–Rényi network simulations. Then, the basic reproductive number (R0) of the genetic network, the group of farms with higher potential for disease spread standing at the top of the production chain, was calculated to identify farms acting as super‐spreaders. Finally, their external biosecurity scores were evaluated. The genetic network in Argentina presented a scale‐free and small‐world topology. Thus, we estimate that disease spread would be fast, preferably to highly connected nodes and with little chances of being contained. Throughout the study, 31 farms were identified as super‐spreaders in the genetic network for all years, while other 55 were super‐spreaders at least once, from an average of 1,613 farms per year. Interestingly, removal of less than 5% of higher degree and betweenness farms resulted in a >90% reduction of R0 indicating that few farms have a key role in disease spread. When biosecurity scores of the most relevant super‐spreaders were examined, it was evident that many were at risk of introducing and disseminating new pathogens across the whole of Argentina's pig production network. These results highlight the usefulness of establishing targeted surveillance and intervention programmes, emphasizing the need for better biosecurity scores in Argentinean swine production units, especially in super‐spreader farms.

    更新日期:2019-12-20
  • Vertical transmission may play a greater role in the spread of Leishmania infantum in synanthropic Mus musculus rodents than previously believed
    Transbound. Emerg. Dis. (IF 3.554) Pub Date : 2019-12-17
    Joaquina Martín‐Sánchez; Nieves Torres‐Medina; Victoriano Corpas‐López; Francisco Morillas‐Márquez; Victoriano Díaz‐Sáez

    Vertical transmission of Leishmania infantum was demonstrated in domestic mice captured close to the home of a patient with leishmaniasis. Leishmania infantum DNA was detected in 88.9% of synanthropic Mus musculus adult rodents and 29.2% of their unborn foetuses. Mother‐to‐infant transmission was observed in all females whose gestational stage was sufficiently advanced to allow foetal analysis (foetal length 2–2.5 cm). The infection rate in foetal samples ranged from 11.1% to 50.0%, with parasite loads of up to 6,481 parasites/5 mg tissue. A low density of Phlebotomus perniciosus was also found (0.2 specimen/CDC trap). Six infected mice captured in March were only 1.5 months old and could thus not have had contact with the vector. Vertical transmission thus appears to play a greater role in the spread of leishmaniasis than previously thought, particularly since rodents are natural hosts for the parasite and are prolific in nature.

    更新日期:2019-12-18
  • Origin and epidemic status of porcine epidemic diarrhea virus variants in China
    Transbound. Emerg. Dis. (IF 3.554) Pub Date : 2019-12-16
    Baochao Fan; Dian Jiao; Ruoxi Zhang; Jinzhu Zhou; Rongli Guo; Zhengyu Yu; Danyi Shi; Yongxiang Zhao; Jun Gu; Beibei Niu; Zengjun Ma; Song Gao; Kongwang He; Bin Li

    From 2010, porcine epidemic diarrhea virus (PEDV) variants caused sequential outbreaks of disease in Asia and the United States. In this retrospective study, 49 complete spike (S) gene sequences were obtained from PEDV strains collected in China from 2014 to 2016. We observed that variant PEDV strains with novel insertions, deletions, and multiple S gene recombination types were present in China. In addition, mixed infections involving different variant strains were observed in some areas. Based on phylogenetic and recombination analyses, we determined that the newly emerged PEDV variants potentially originated via recombination between the earliest Chinese G1 genogroup strain, JS‐2004‐2 and earlier Korean pandemic strains. These findings provide important information for understanding ongoing PEDV outbreaks and suggest that novel variants make it more difficult to prevent PEDV infection.

    更新日期:2019-12-17
  • Emerging strains of porcine epidemic diarrhoea virus (PEDv) in Mexico
    Transbound. Emerg. Dis. (IF 3.554) Pub Date : 2019-12-16
    Saúl Reveles‐Félix; Rosalba Carreón‐Nápoles; Susana Mendoza‐Elvira; Víctor Quintero‐Ramírez; Juvencio García‐Sánchez; Rebeca Martínez‐Bautista; Manuel Saavedra‐Montañez; Juan Joel Mosqueda Gualito; José Ivan Sánchez‐Betancourt

    As an emerging disease, the porcine epidemic diarrhoea virus has caused substantial economic losses to the pork industry in Mexico, leading to piglet mortality rates of up to 100%. For detection, sequencing and genetic characterization of the virus, 68 samples of one‐week‐old piglets from pork farms in 17 states of Mexico were analysed. In total, 53 samples were positive by real‐time RT‐PCR, confirming the presence of the virus in 15 states. Twenty‐eight samples from 10 states were amplified by endpoint RT‐PCR, and 20 sequences of the spike gene were obtained. A phylogenetic analysis based on the spike gene demonstrated that all Mexican strains are in Group II and are classified as non‐Indel‐S emerging variants. Three strains showed amino acid insertions: PEDv/MEX/GTO/LI‐DMZC15/2015 and PEDv/MEX/QRO/LI‐DMZC45/2016 showed one amino acid insertion (424Y425 and 447D448, respectively), and PEDv/MEX/QRO/LI‐DMZC49/2019 showed one and two amino acid insertions (422C423 and 537SQ538), with the second insertion in the COE region. These results provide evidence of the prevalence of emerging, non‐Indel‐S strains of the virus are currently circulating in Mexico during 2016–2018, when three of which have amino acid insertions: PEDv/MEX/GTO/IN‐DMZC15/2015 and PEDv/MEX/QRO/IN‐DMZC45/2016 have one amino acid insertion each (424Y425 and 447D448, respectively), and PEDv/MEX/QRO/IN‐DMZC49/2019 has one (422C423) and two amino acid insertions (537SQ538), the latter being in the COE region, which could generate new antigenic variants.

    更新日期:2019-12-17
  • Co‐circulation and characterization of HPAI‐H5N1 and LPAI‐H9N2 recovered from a duck farm, Yogyakarta, Indonesia
    Transbound. Emerg. Dis. (IF 3.554) Pub Date : 2019-12-16
    Lestari; Hendra Wibawa; Elly Puspasari Lubis; Rama Dharmawan; Rina Astuti Rahayu; Herdiyanto Mulyawan; Kamonpan Charoenkul; Chanakarn Nasamran; Bagoes Poermadjaja; Alongkorn Amonsin

    In July 2016, an avian influenza outbreak in duck farms in Yogyakarta province was reported to Disease Investigation Center (DIC), Wates, Indonesia, with approximately 1,000 ducks died or culled. In this study, two avian influenza (AI) virus subtypes, A/duck/Bantul/04161291‐OR/2016 (H5N1) and A/duck/Bantul/04161291‐OP/2016 (H9N2) isolated from ducks in the same farm during an AI outbreak in Bantul district, Yogyakarta province, were sequenced and characterized. Our results showed that H5N1 virus was closely related to the highly pathogenic AI (HPAI) H5N1 of clade 2.3.2.1c, while the H9N2 virus was clustered with LPAI viruses from China, Vietnam and Indonesia H9N2 (CVI lineage). Genetic analysis revealed virulence characteristics for both in avian and in mammalian species. In summary, co‐circulation of HPAI‐H5N1 of clade 2.3.2.1c and LPAI‐H9N2 was identified in a duck farm during an AI outbreak in Yogyakarta province, Indonesia. Our findings raise a concern of the potential risk of the viruses, which could increase viral transmission and/or threat to human health. Routine surveillance of avian influenza viruses should be continuously conducted to understand the dynamic and diversity of the viruses for influenza prevention and control in Indonesia and SEA region.

    更新日期:2019-12-17
  • Leptospirosis trends in China, 2007–2018: A retrospective observational study
    Transbound. Emerg. Dis. (IF 3.554) Pub Date : 2019-12-16
    Hui Zhang; Cuicai Zhang; Yongzhang Zhu; Khalid Mehmood; Jinjing Liu; Sean P. McDonough; Zhaoxin Tang; Yung‐Fu Chang

    Leptospirosis is one of the most common and neglected tropical waterborne diseases in China, causing serious economic losses, and constituting a significant public health threat. Leptospirosis has recently received increased attention and is considered a re‐emerging infectious disease in many countries. The incidence of leptospirosis among people suggests that occupation, age, season, sex and water recreational activities are significant risk factors. The aim of this study was to describe the epidemiological profiles of leptospirosis in China during the 2007–2018 period. The morbidity data of leptospirosis by age, season (month), gender, occupation and geographic location (different provinces) were obtained from the public health science data centre of China for subsequent epidemiological analysis. The results indicate that the incidence of leptospirosis has shown a slow downward trend from 2007 to 2018, but morbidity rates were still relatively high (0.0660–0.0113). The incidence of leptospirosis varied in different provinces of China; cases localized mainly to the Southern and Central provinces, areas with warm weather and ample rainfall. Older people (aged 60–75), males, farmers, students and field workers were high‐risk populations. During the 2007–2018 observation period, morbidity rates increased beginning in May, remained at high levels in August and September and decreased after November. The present investigation highlights the re‐emergence of leptospirosis in some provinces of China (especially in Yunnan and Fujian) and shows that leptospirosis remains a serious public health threat. The results of this study should enhance measures taken for the prevention, control, and surveillance of leptospirosis in China.

    更新日期:2019-12-17
  • Genetic and pathogenic characteristics of clade 2.3.2.1c H5N1 highly pathogenic avian influenza viruses isolated from poultry outbreaks in Laos during 2015–2018
    Transbound. Emerg. Dis. (IF 3.554) Pub Date : 2019-12-15
    Yu‐Ri Park; Yu‐Na Lee; Dong‐Hun Lee; Yoon‐Gi Baek; Young‐Jae Si; Phetlamphone Meeduangchanh; Watthana Theppangna; Bounlom Douangngeun; Soo‐Jeong Kye; Myoung‐Heon Lee; Choi‐Kyu Park; Youn‐Jeong Lee

    Since 2004, there have been multiple outbreaks of H5 highly pathogenic avian influenza (HPAI) viruses in Laos. Here, we isolated H5N1 HPAI viruses from poultry outbreaks in Laos during 2015–2018 and investigated their genetic characteristics and pathogenicity in chickens. Phylogenetic analysis revealed that the isolates belonged to clade 2.3.2.1c and that they differed from previous Laos viruses with respect to genetic composition. In particular, the isolates were divided into two genotypes, each of which had a different NS segments. The results of possible migration analysis suggested a high likelihood that the Laos isolates were introduced from neighbouring countries, particularly Vietnam. The recent Laos isolate, A/Duck/Laos/NL‐1504599/2018, had an intravenous pathogenicity index score of 3.0 and showed a 50% chicken lethal dose of 102.5 EID50/0.1 ml, indicating high pathogenicity. The isolated viruses exhibited no critical substitution in the markers associated with mammalian adaptation, but possess markers related to neuraminidase inhibitor resistance. These results emphasize the need for ongoing surveillance of circulating influenza virus in South‐East Asia, including Laos, to better prepare for and mitigate global spread of H5 HPAI.

    更新日期:2019-12-17
  • A molecular epidemiological investigation of PEDV in China: Characterization of co‐infection and genetic diversity of S1‐based genes
    Transbound. Emerg. Dis. (IF 3.554) Pub Date : 2019-12-13
    Mingjun Su; Chunqiu Li; Shanshan Qi; Dan Yang; Ning Jiang; Baishuang Yin; Donghua Guo; Fanzhi Kong; Dongwei Yuan; Li Feng; Dongbo Sun

    Porcine epidemic diarrhoea virus (PEDV) is an emerging and re‐emerging epizootic virus of swine that causes substantial economic losses to the pig industry in China and other countries. The variations in the virus, and its co‐infections with other enteric viruses, have contributed to the poor control of PEDV infection. In the current study, a broad epidemiological investigation of PEDV was carried out in 22 provinces or municipalities of China during 2015–2018. The enteric viruses causing co‐infection with PEDV and the genetic diversity of the PEDV S1 gene were also analysed. The results indicated that, of the 543 diarrhoea samples, 66.85% (363/543) were positive for PEDV, and co‐infection rates of PEDV with 13 enteric viruses ranged from 3.58% (13/363) to 81.55% (296/363). Among these enteric viruses, the signs of diarrhoea induced by PEDV were potentially associated with co‐infections with porcine enterovirus 9/10 (PEV) and torque teno sus virus 2 (TTSuV‐2) (p < .05). The 147 PEDV strains identified in our study belong to Chinese pandemic strains and exhibited genetic diversity. The virulence‐determining S1 proteins of PEDV pandemic strains were undergoing amino acid mutations, in which S58_S58insQGVN–N135dup–D158_I159del‐like mutations were common patterns (97.28%, 143/147). When compared with 2011–2014 PEDV strains, the amino acid mutations of PEDV pandemic strains were mainly located in the N‐terminal domain of S1 (S1‐NTD), and 21 novel mutations occurred in 2017 and 2018. Furthermore, protein homology modelling showed that the mutations in pattern of insertion and deletion mutations of the S1 protein of PEDV pandemic strains may have caused structural changes on the surface of the S1 protein. These data provide a better understanding of the co‐infection and genetic evolution of PEDV in China.

    更新日期:2019-12-17
  • Improving Village Animal Health Worker participation in national disease surveillance systems: A case study from Cambodia
    Transbound. Emerg. Dis. (IF 3.554) Pub Date : 2019-12-11
    Isabel MacPhillamy, James Young, Sophary Siek, Chan Bun, Sothoeun Suon, Jenny‐Ann Toribio, Peter Windsor, Russell Bush

    Para‐veterinary systems have arisen in numerous developing countries to address the low capacity of national veterinary services in meeting livestock health demands of mainly smallholder farmers. In Cambodia, the village animal health worker (VAHW) system was established in the early 1990s, involving short training programmes to equip VAHWs to provide basic animal health services for smallholder farmers, particularly the vaccination of cattle for haemorrhagic septicaemia (HS). However, there are increasing expectations that VAHWs provide village level disease surveillance information to the national veterinary services, despite their low‐level disease diagnostic skills. To identify opportunities to improve the disease reporting system in Cambodia, a closed‐ended cross‐sectional study of VAHWs (n = 80) from two provinces was conducted in 2015, examining their contact frequency with district and provincial animal health authorities. Ordinal logistic regression was used to determine factors associated with increased frequency of VAHW contact with the district animal health authorities responsible for national disease reporting. Positive associations between income generated from VAHW activities (p = .01) and the frequency of visiting farmers (p < .0001), with more frequent contacts with district animal health authorities, were identified. High levels of inappropriate use of antibiotics, with almost 90% of VAHW reporting they use antibiotics to treat FMD‐affected animals, were reported. Although further research to increase the rates of reporting at the smallholder farmer and VAHW levels is required, increased emphasis on complying with the World Organisation for Animal Health's competency guidelines for veterinary paraprofessionals may be required if they are expected to contribute to national animal disease surveillance systems.

    更新日期:2019-12-11
  • Molecular characterization of group A rotavirus from rhesus macaques (Macaca mulatta) at human–wildlife interfaces in Bangladesh
    Transbound. Emerg. Dis. (IF 3.554) Pub Date : 2019-12-10
    Ariful Islam, Mohammad Enayet Hossain, Najmul Haider, Melinda K. Rostal, Sanjoy Kumar Mukharjee, Jinnat Ferdous, Mojnu Miah, Mustafizur Rahman, Peter Daszak, Mohammed Ziaur Rahman, Jonathan H. Epstein

    Group A rotavirus (RVA) is an important cause of diarrhoea in people, especially children, and animals globally. Due to the segmented nature of the RVA genome, animal RVA strains have the potential to adapt to the human host through reassortment with other co‐infecting human viruses. Macaques share food and habitat with people, resulting in close interaction between these two species. This study aimed to detect and characterize RVA in rhesus macaques (Macaca mulatta) in Bangladesh. Faecal samples (N = 454) were collected from apparently healthy rhesus macaques from nine different sites in Bangladesh between February and March 2013. The samples were tested by one‐step, real‐time, reverse transcriptase‐polymerase chain reaction (PCR). Four percent of samples (n = 20; 95% CI 2.7%–6.7%) were positive for RVA. RVA positive samples were further characterized by nucleotide sequence analysis of two structural protein gene fragments, VP4 (P genotype) and VP7 (G genotype). G3, G10, P[3] and P[15] genotypes were identified and were associated as G3P[3], G3P[15] and G10P[15]. The phylogenetic relationship between macaque RVA strains from this study and previously reported human strains indicates possible transmission between humans and macaques in Bangladesh. To our knowledge, this is the first report of detection and characterization of rotaviruses in rhesus macaques in Bangladesh. These data will not only aid in identifying viral sharing between macaques, human and other animals, but will also improve the development of mitigation measures for the prevention of future rotavirus outbreaks.

    更新日期:2019-12-11
  • First detection of koi herpesvirus and carp oedema virus in Iraq associated with a mass mortality in common carp (Cyprinus carpio)
    Transbound. Emerg. Dis. (IF 3.554) Pub Date : 2019-12-09
    Anna Toffan, Andrea Marsella, Miriam Abbadi, Salah Abass, Basem Al‐Adhadh, Gareth Wood, David Michael Stone

    At the end of October 2018, a mass fish mortality occurred in Iraq, involving thousands of tons of cultured and wild common carp (Cyprinus carpio) along Euphrates and Tigris rivers. Fish were found dead or moribund along rivers coasts, showing lethargy, dyspnoea and flared gills. At necropsy, discoloration patches were noticed on the gills. Wet preparations showed rare metacercariae and Dactylogyrus spp. Samples were subjected to bacteriological tests and virological investigation through real‐time PCR and nested PCR. Both were positive for koi herpesvirus (KHV) and carp oedema virus. Results obtained were confirmed by the OIE reference laboratory of KHV disease (KHVD) at Cefas (UK) and by sequence analysis. This is the first report on the detection of both viruses in Iraq.

    更新日期:2019-12-09
  • Natural infection of a variant pseudorabies virus leads to bovine death in China
    Transbound. Emerg. Dis. (IF 3.554) Pub Date : 2019-12-06
    Zilong Cheng, Zhengjie Kong, Peng Liu, Zhendong Fu, Jiandong Zhang, Mengda Liu, Yingli Shang

    Pseudorabies virus (PRV) infects numerous species of domestic and wild animals leading to severe diseases especially in swine and cattle. Since 2011, the variant PRVs were identified in pigs, which were genetically different from classic strains. Although variant PRV infection is widely observed in pigs, there is still no report of variant PRV infection in cattle. Here, we reported a natural infection of variant PRV leading to acute bovine death in Eastern China. Our study suggests that the new variant PRV strains could be a potential threat to cattle industry and possibly to the public health of human.

    更新日期:2019-12-06
  • Reverse‐transcription recombinase‐aided amplification assay for H7 subtype avian influenza virus
    Transbound. Emerg. Dis. (IF 3.554) Pub Date : 2019-12-04
    Suchun Wang, Baoxu Huang, Xuejun Ma, Ping Liu, Yang Wang, Xiaoguang Zhang, Lin Zhu, Qingying Fan, Yawei Sun, Kaicheng Wang

    H7 subtype avian influenza virus infection is an emerging zoonosis in some Asian countries and an important avian disease worldwide. A rapid and simple test is needed to confirm infection in suspected cases during disease outbreaks. In this study, we developed a reverse‐transcription recombinase‐aided amplification assay for the detection of H7 subtype avian influenza virus. Assays were performed at a single temperature (39°C), and the results were obtained within 20 min. The assay showed no cross‐detection with Newcastle disease virus or infectious bronchitis virus, which are the other main respiratory viruses affecting birds. The analytical sensitivity was 102 RNA copies per reaction at a 95% probability level according to probit regression analysis, with 100% specificity. Compared with published reverse‐transcription quantitative real‐time polymerase chain reaction assays, the κ value of the reverse‐transcription recombinase‐aided amplification assay in 342 avian clinical samples was 0.988 (p < .001). The sensitivity for avian clinical sample detection was 100% (95%CI, 90.40%–100%), and the specificity was 99.96% (95%CI, 97.83%–99.98%). These results indicated that our reverse‐transcription recombinase‐aided amplification assay may be a valuable tool for detecting avian influenza H7 subtype virus.

    更新日期:2019-12-05
  • Lack of evidence for the presence of leprosy bacilli in red squirrels from North‐West Europe
    Transbound. Emerg. Dis. (IF 3.554) Pub Date : 2019-12-02
    Maria Tió‐Coma, Hein Sprong, Marja Kik, Jaap T. van Dissel, Xiang‐Yang Han, Toine Pieters, Annemieke Geluk

    Leprosy is a human infectious disease caused by Mycobacterium leprae or Mycobacterium lepromatosis that can also occur in animals and even manifest as zoonosis. Recently, both mycobacteria were detected in red squirrels (Sciurus vulgaris) from the British Isles. To further explore the presence of leprosy bacilli in North‐West Europe, we screened Belgian and Dutch squirrels. Tissue samples from 115 animals tested by qPCR were negative for both pathogens. No molecular or pathological evidence was found of the presence of these zoonotic pathogens in North‐West Europe.

    更新日期:2019-12-02
  • Geo‐climatic factors in a newly emerging focus of zoonotic visceral leishmaniasis in rural areas of north‐eastern Iran
    Transbound. Emerg. Dis. (IF 3.554) Pub Date : 2019-12-01
    Mohammad Amin Ghatee, Mahdi Fakhar, Majid Derakhshani‐Niya, Zeynab Behrouzi, Saeed Hosseini Teshnizi

    Visceral leishmaniasis (VL) is the fatal form of leishmaniasis. A newly emerging focus of zoonotic VL (ZVL) including 13 villages has been reported from Maraveh Tappeh County, Golestan province, north‐eastern Iran. We investigated the effect of climatic and environmental factors on the occurrence of disease in this focus by geographical information systems (GIS) approaches and logistic regression models. The incidence rate of ZVL in human and dog population was estimated 1.2% and 27.3%, respectively, in the studied areas. Rock soil type (OR = 11.7), rainfall (OR = 1.04) and elevation (OR = 0.99) were found as determinants of ZVL. Also, almost all infected villages were in close proximity of rivers. Cavities of rock soil around rivers are assumed as suitable areas for sandfly resting and growth by providing shadow and moisture. Rainfall also provides appropriate moisture in semi‐arid regions for survival of sandflies. The negative effect of higher altitude can be explained by some sandfly life‐limiting conditions like freezing weather. Accordingly, regions with lower altitude and higher rainfall, covered by rock and in close proximity of rivers, are the hazard zones for ZVL in the Maraveh Tappeh. Air humidity, temperature, land cover type and slope were not predictors of disease in the current study. Further investigations on human population movement, probable reservoirs and vectors of disease can provide valuable data for modelling the future distribution of ZVL in the Iranian province.

    更新日期:2019-12-02
  • First report of a novel goose astrovirus outbreak in Cherry Valley ducklings in China
    Transbound. Emerg. Dis. (IF 3.554) Pub Date : 2019-12-01
    Hao Chen, Bin Zhang, Min Yan, Youxiang Diao, Yi Tang

    A highly acute disease broke out in ducklings in Shandong Province in March 2019. The disease was characterized as visceral gout, with a mortality rate of 30%. The causative agent, which has given rise to similar symptoms in goslings, has been confirmed to be a novel goose astrovirus. The novel goose astrovirus, which was designated as the SDXT strain, was identified from a diseased duck farm using duck embryo primary cells in an experimental infection test. Genomic sequence analysis, as well as phylogenetic analysis of the viral proteins, revealed that the SDXT strain was closely related to a novel goose astrovirus of the Avastrovirus three species. These results indicate that the novel goose astrovirus may cross‐host infect ducklings. Further studies are needed to define its host range and transmission route.

    更新日期:2019-12-02
  • Prediction for global African swine fever outbreaks based on a combination of random forest algorithms and meteorological data
    Transbound. Emerg. Dis. (IF 3.554) Pub Date : 2019-12-01
    Ruirui Liang, Yi Lu, Xiaosheng Qu, Qiang Su, Chunxia Li, Sijing Xia, Yongxin Liu, Qiang Zhang, Xin Cao, Qin Chen, Bing Niu

    African swine fever (ASF) is a virulent infectious disease of pigs. As there is no effective vaccine and treatment method at present, it poses a great threat to the pig industry once it breaks out. In this paper, we used ASF outbreak data and the WorldClim database meteorological data and selected the CfsSubset Evaluator‐Best First feature selection method combined with the random forest algorithms to construct an African swine fever outbreak prediction model. Subsequently, we also established a test set for data other than modelling, and the accuracy accuracy value range of the model on the independent test set was 76.02%–84.64%, which indicated that the modelling effect was better and the prediction accuracy was higher than previous estimates. In addition, logistic regression analysis was conducted on 12 features used for modelling and the ROC curves were drawn. The results showed that the bio14 features (precipitation of driest month) had the largest contribution to the outbreak of ASF, and it was speculated that the outbreak of the epidemic was significantly related to precipitation. Finally, we used this qualitative prediction model to build a global online prediction system for ASF outbreaks, in the hope that this study will help to decision‐makers who can then take the relevant prevention and control measures in order to prevent the further spread of future epidemics of the disease.

    更新日期:2019-12-02
  • Spatiotemporal reconstruction and transmission dynamics during the 2016–17 H5N8 highly pathogenic avian influenza epidemic in Italy
    Transbound. Emerg. Dis. (IF 3.554) Pub Date : 2019-12-01
    William T. Harvey, Paolo Mulatti, Alice Fusaro, Francesca Scolamacchia, Bianca Zecchin, Isabella Monne, Stefano Marangon

    Effective control of avian diseases in domestic populations requires understanding of the transmission dynamics facilitating viral emergence and spread. In 2016–17, Italy experienced a significant avian influenza epidemic caused by a highly pathogenic A(H5N8) virus, which affected domestic premises housing around 2.7 million birds, primarily in the north‐eastern regions with the highest density of poultry farms (Lombardy, Emilia‐Romagna and Veneto). We perform integrated analyses of genetic, spatiotemporal and host data within a Bayesian phylogenetic framework. Using continuous and discrete phylogeography, we estimate the locations of movements responsible for the spread and persistence of the epidemic. The information derived from these analyses on rates of transmission between regions through time can be used to assess the success of control measures. Using an approach based on phylogenetic–temporal distances between domestic cases, we infer the presence of cryptic wild bird‐mediated transmission, information that can be used to complement existing epidemiological methods for distinguishing transmission within the domestic population from incursions across the wildlife–domestic interface, a common challenge in veterinary epidemiology. Spatiotemporal reconstruction of the epidemic reveals a highly skewed distribution of virus movements with a high proportion of shorter distance local movements interspersed with occasional long‐distance dispersal events associated with wild birds. We also show how such inference be used to identify possible instances of human‐mediated movements where distances between phylogenetically linked domestic cases are unusually high.

    更新日期:2019-12-02
  • Heterogeneous Puumala orthohantavirus situation in endemic regions in Germany in summer 2019
    Transbound. Emerg. Dis. (IF 3.554) Pub Date : 2019-11-29
    Florian Binder, Stephan Drewes, Christian Imholt, Marion Saathoff, Diana Alexandra Below, Elias Bendl, Franz J. Conraths, Peter Tenhaken, Maren Mylius, Stefan Brockmann, Rainer Oehme, Jona Freise, Jens Jacob, Rainer G. Ulrich

    Puumala orthohantavirus (PUUV) causes most human hantavirus disease cases in Europe. PUUV disease outbreaks are usually synchronized Germany‐wide driven by beech mast‐induced irruptions of its host (bank vole, Myodes glareolus). Recent data indicate high vole abundance, high PUUV prevalence and high human incidence in summer 2019 for some regions, but elsewhere values were low to moderate. This significant lack of synchrony among regions in Germany is in contrast to previous studies. Health institutions need to be informed about the heterogeneous distribution of human PUUV infection risk to initiate appropriate actions.

    更新日期:2019-11-30
  • Seroprevalence of Rift valley fever in South African domestic and wild suids (1999–2016)
    Transbound. Emerg. Dis. (IF 3.554) Pub Date : 2019-11-26
    Baratang Alison Lubisi, Phumudzo Nomicia Ndouvhada, Donald Neiffer, Mary Louise Penrith, Donald‐Ray Sibanda, Armanda Bastos

    Rift valley fever (RVF) is a vector‐borne viral disease of domestic ruminants, camels and man, characterized by widespread abortions and neonatal deaths in animals, and flu‐like symptoms, which can progress to hepatitis and encephalitis in humans. The disease is endemic in Africa, Saudi Arabia and Yemen, and outbreaks occur after periods of high rainfall, or in environments supporting the proliferation of RVF virus (RVFV)‐infected mosquito vectors. The domestic and wild animal maintenance hosts of RVFV, which may serve as sources of virus during inter‐epidemic periods (IEPs) and contribute to occurrence of sporadic outbreaks, remain unknown, although reports indicate that the African buffalo (Syncerus caffer) may play a role. Due to the close proximity of the habitats of domestic pigs and warthogs to those of known domestic and wild ruminant RVFV maintenance hosts respectively, our study investigated their possible role in the epidemiology of RVF in South Africa by evaluating RVFV exposure and seroconversion in suids. A total of 107 warthog and 3,984 domestic pig sera from 2 and all 9 provinces of South Africa, respectively, were screened for presence of RVFV neutralizing antibodies using the virus neutralization test (VNT). Sero‐positivity rates of 1.87% (95% CI: 0.01%–6.9%) and 0.68% (95% CI: 0.49%–1.04%) were observed for warthogs and domestic pigs, respectively, but true prevalence rates, taking test sensitivity and specificity into account, were lower for both groups. There was a strong association between the results of the two groups (χ2 = 0.75, p = .38), and differences in prevalence between the epidemic and IEPs were non‐significant for all suid samples tested (p > .05). This study, which provides the first evidence of probable exposure and infection of South African domestic pigs and warthogs to RVFV, indicates that further investigations are warranted, to fully clarify the role of suids in the epidemiology of RVF.

    更新日期:2019-11-27
  • Comparative in vivo pathogenicity study of an ITA genotype isolate (G6) of infectious bursal disease virus
    Transbound. Emerg. Dis. (IF 3.554) Pub Date : 2019-11-24
    Caterina Lupini, Viviana Felice, Flavio Silveira, Giulia Mescolini, Giacomo Berto, Valeria Listorti, Mattia Cecchinato, Elena Catelli

    Recently, a new genotype of infectious bursal disease virus (IBDV), named ITA, was detected in IBD‐vaccinated Italian broilers. Genome characterization revealed ITA to be a genetically different IBDV, belonging to genogroup 6 according to a recently proposed IBDV classification. The currently available clinical data do not allow any definition of the degree of pathogenicity of the ITA‐IBDV isolates. In the present study, a pathogenicity trial was conducted by the oral inoculation of specific‐pathogen‐free (SPF) chickens. Birds were housed in poultry isolators and inoculated at 35 days of age with an ITA‐IBDV isolate (35 birds) or a strain belonging to the G1a genogroup as a comparison (35 birds). Control birds (25 birds) were contextually mock‐inoculated with sterile water. Birds were observed daily for clinical signs and at 0, 7, 14, 21 and 28 days post‐inoculation (dpi) were bled for IBDV antibody detection. At 2, 4, 7, 14, 21 and 28 dpi, five birds from each of the inoculated groups, and three from the control group, were euthanized and subjected to a post‐mortem examination; the bursa:body weight and thymus:body weight ratios were calculated. Microscopic lesions of the bursa and thymus were scored on the basis of lymphoid necrosis and/or depletion or cortex atrophy, respectively. Both viruses induced a subclinical course of disease, as neither clinical signs nor mortality were recorded during the study, even in the presence of typical IBDV gross and microscopic lesions. Bursal damage, measured by the bursa:body weight ratio, was more noticeable and precocious after ITA‐IBDV inoculation. Histopathology scores of the bursa, indicative of rapid lymphoid depletion, confirmed the aggressiveness of the ITA‐IBDV strain in this organ. This study showed that, although the ITA‐IBDV strain tested causes infection with a subclinical course, it induces severe damage to lymphoid tissues. Therefore, its circulation in birds might be a threat for the poultry industry and may jeopardize the success of the production cycle.

    更新日期:2019-11-26
  • Genetic diversity of pathogenic leptospires from wild, domestic and captive host species in Portugal
    Transbound. Emerg. Dis. (IF 3.554) Pub Date : 2019-11-24
    Ana S. Ferreira, Ahmed Ahmed, Teresa Rocha, Maria L. Vieira, Maria das Neves Paiva‐Cardoso, João R. Mesquita, Hans van der Linden, Marga Goris, Gertrude Thompson, Rudy A. Hartskeerl, João Inácio

    Leptospirosis is a neglected zoonotic disease of worldwide distribution with a significant veterinary and public health impact. It is caused by pathogenic bacteria of the genus Leptospira. The availability of effective tools to accurately identify and type leptospires is of utmost importance for the diagnosis of the disease and for assessing its epidemiology. Several multi‐locus sequence typing (MLST) approaches were described for the typing of worldwide isolates of Leptospira but an extensive agreement towards the adoption of a unique consensus scheme for this agent is still lacking. Most genotyped strains originate from Asian and South American countries, with a minority originating from Europe (being most countries represented only by one or a few isolates). The knowledge of the diversity of circulating leptospires is the key to understanding the disease transmission and its zoonotic implications. In this study, we revisited the taxonomy of several isolates of pathogenic Leptospira obtained from domestic, wild and captive animals in Portugal, between 1990 and 2012. A selection of these isolates was genotyped using two previously published MLST schemes. A total of seven distinct sequence types (STs) were detected among the Portuguese isolates with two STs representing L. borgpetersenii (ST149 and ST152), two STs representing L. kirschneri (ST117 and ST100) and three STs representing L. interrogans (ST17, ST24 and ST140). Global widespread (and maybe more virulent) Leptospira genotypes seem to circulate in Portugal, particularly the L. interrogans ST17 isolates which are associated with several outbreaks of leptospirosis among humans and animals in different regions of the world. This study contributes to the enrichment of the global MLST databases with a new set of allele and sequence type information also providing novel data on circulating Leptospira serovars in Portugal.

    更新日期:2019-11-26
  • The pulmonary virome, bacteriological and histopathological findings in bovine respiratory disease from western Canada
    Transbound. Emerg. Dis. (IF 3.554) Pub Date : 2019-11-24
    Maodong Zhang, Janet E. Hill, Dale L. Godson, Musangu Ngeleka, Champika Fernando, Yanyun Huang

    The aetiology and pathogenesis of bovine respiratory disease (BRD) are complex and involve the interplay of infectious agents, management and environmental factors. Previous studies of BRD focused on ante‐mortem samples from the upper respiratory tract and identified several unconventional viruses. The lung, however, is the primary location where significant BRD lesions are usually found and is a common post‐mortem diagnostic specimen. In this study, results of high‐throughput virome sequencing, bacterial culture, targeted real‐time PCR and histological examination of 130 bovine pneumonic lungs from western Canadian cattle were combined to explore associations of microorganisms with different types of pneumonia. Fibrinous bronchopneumonia (FBP) was the predominant type of pneumonia (46.2%, 60/130) and was associated with the detection of Mannheimia haemolytica. Detection of Histophilus somni and Pasteurella multocida was associated with suppurative bronchopneumonia (SBP) and concurrent bronchopneumonia and bronchointerstitial pneumonia (BP&BIP), respectively. Sixteen viruses were identified, of which bovine parvovirus 2 (BPV2) was the most prevalent (11.5%, 15/130) followed by ungulate tetraparvovirus 1 (UTPV1, 8.5%, 11/130) and bovine respiratory syncytial virus (BRSV, 8.5%, 11/130). None of these viruses, however, were significantly associated with a particular type of pneumonia. Unconventional viruses such as influenza D virus (IDV) and bovine rhinitis B virus (BRBV) were detected, although sparsely, consistent with our previous findings in upper respiratory tract samples. Taken together, our results show that while virus detection in post‐mortem lung samples is of relatively little diagnostic value, the strong associations of H. somni and M. haemolytica with SBP and FBP, respectively, indicate that histopathology can be useful in differentiating bacterial aetiologies.

    更新日期:2019-11-26
  • The emergence of subclades A1 and A3 avipoxviruses in India
    Transbound. Emerg. Dis. (IF 3.554) Pub Date : 2019-11-23
    Basanta Pravas Sahu, Prativa Majee, Chinmayee Mishra, Manojita Dash, Sangram Biswal, Niranjan Sahoo, Debasis Nayak

    During the years 2010–2018, avipoxvirus (APV) outbreaks were observed in the domestic chickens and pigeons present in the eastern Indian state of Odisha. Based on typical pox lesions, followed by molecular techniques, the overall morbidity was found to be 18%–19.23% and 16.92%–23% in chickens and pigeons, respectively. The cutaneous forms of the disease were observed with varied rates of mortality, being 47.36%–52.77% in chickens and 39.13%–92% in pigeons. PCR amplification targeting the viral P4b core protein‐coding gene and the DNA polymerase gene confirmed the presence of APV strains in 10 birds. Subsequent phylogenetic analysis of these two genes confirmed that the circulating strains were members of APV clade A. The subclade analysis revealed the introduction of A1 and A3 subclades in Indian chickens and pigeons, respectively. This study is the first molecular record of APVs circulating in eastern Indian birds (Odisha) and involves the first use of the polymerase gene to reveal the circulating clades of Indian APVs.

    更新日期:2019-11-26
  • Rabies surveillance in wild mammals in South of Brazil
    Transbound. Emerg. Dis. (IF 3.554) Pub Date : 2019-11-21
    Aline Alves Scarpellini Campos, Raíssa Nunes dos Santos, Julio A. Benavides, Helena Beatriz de Carvalho Ruthner Batista, Fernando Finoketti, Paulo Guilherme Carniel Wagner, Bruna Zafalon‐Silva, Marcelo Alievi, Fabio Branco da Silva, André Witt, Ana Tartarotti, Andrea de Cassia Rodrigues da Silva, Karin Correa Sheffer Ferreira, Ana Paula Guedes Frazzon, Paulo Michel Roehe, Ana Cláudia Franco

    The sylvatic cycle of rabies, caused by the Rabies lyssavirus (RABV), is maintained in the American Continent by aerial and terrestrial wild mammals. In this study, we combined passive surveillance of rescued wild animals with active serological surveillance in targeting areas at Rio Grande do Sul State and Santa Catarina State, south of Brazil, where bites of humans by wild animals have been reported. Circulation of RABV in Brazilian bats has been extensively demonstrated; however, the observation of such infections in unvaccinated terrestrial mammals is restricted to some regions of the Brazilian territory. The occurrence of rabies infection in unvaccinated animals has been identified by the detection of RABV antigens in brain tissues of dead animals or anti‐rabies antibodies in live animals. Such strategies allow the surveillance of rabies and the assessment of spillover risks from infected animals to humans. Our aim included the identification of species of wild mammals that are involved in the sylvatic cycle of rabies virus in Southern Brazil and to assess the risk of rabies infection in patients bitten by wild animals in the state. To assess the anti‐rabies seropositivity, sera were submitted to the Rapid Fluorescent Focus Inhibition Test (RFFIT). Among the 100 mammals tested, five animals were seropositive (5%) including three (one primate and two wild canids) with rabies virus neutralizing antibodies titres >0.5 IU/ml. Our results highlight the exposure to RABV of both primates and wild canids in Southern Brazil and suggest the occurrence of RABV exposure without the development of further symptoms. Further research should clarify the dynamics of rabies in wild canids and whether primates are accidental hosts or reservoirs for RABV at this region.

    更新日期:2019-11-21
  • Emerging lethal infectious bronchitis coronavirus variants with multiorgan tropism
    Transbound. Emerg. Dis. (IF 3.554) Pub Date : 2019-11-20
    Yao‐Tsun Li, Ting‐Chih Chen, Shu‐Yi Lin, Masaji Mase, Shin Murakami, Taisuke Horimoto, Hui‐Wen Chen

    Infectious bronchitis virus (IBV) causes respiratory diseases in chickens and poses an economic threat to the poultry industry worldwide. Despite vaccine use, there have been field outbreaks of IBV in Taiwan. This study aimed to characterize the emerging IBV variants circulating in Taiwan. The analysis of the structural protein genes showed that these variants emerged through frequent recombination events among Taiwan strains, China strains, Japan strains and vaccine strains. Cross‐neutralization tests revealed that two of the variants exhibited novel serotypes. Clinicopathological assessment showed that two of the variants caused high fatality rates of 67% and 20% in one‐day‐old SPF chicks, and all the variants possessed multiorgan tropisms, including trachea, proventriculus and urogenital tissues. Furthermore, the commercial live‐attenuated Mass‐type vaccine conferred poor protection against these variants. This study identified novel genotypes, serotypes and pathotypes of emerging IBV variants circulating in Taiwan. There is an urgent need for effective countermeasures against these variant strains.

    更新日期:2019-11-21
  • A comparison of the efficacy of two commercial acaricides (fipronil and amitraz) with Azadirachta indica (neem) on the brown dog tick (Rhipicephalus sanguineus) from canines in Trinidad
    Transbound. Emerg. Dis. (IF 3.554) Pub Date : 2019-11-19
    Rachel‐Ann Suraj, Rhea Rambarran, Krista Ali, Danyelle Harbajan, Roxanne Charles, Candice Sant, Karla Georges, Sharianne Suepaul

    The brown dog tick (Rhipicephalus sanguineus) is prevalent on canids in Trinidad. It is directly (by causing anaemia) and indirectly (by acting as a vector of tick‐borne pathogens) responsible for morbidity and mortalities in the canine population. The most commonly used commercial acaricides available to pet owners in Trinidad are amitraz and fipronil. Often, these acaricides may be abused and misused in a desperate attempt to rid pets of ticks. The objective of this study was to compare the efficacy of amitraz and fipronil with the herbal alternative, neem (Azadirachta indica). Triplicate in vitro trials utilizing the Larval Packet Test (LPT) were conducted using three concentrations (low, recommended and high) of fipronil (0.025%, 0.05% and 0.1%), amitraz (0.01%, 0.02% and 1%), neem oil (10%, 20% and 40%) and neem leaf extract (0.25%, 0.5% and 2%) for each trial. Statistical analysis using the mixed‐effect Poisson regression analysis indicated that there was a significant difference (p < .05) in the survival of ticks pre‐treatment versus post‐treatment with amitraz, fipronil and all controls when compared to the neem oil. Fipronil and amitraz caused ≥99% mortality for all concentrations used in this study. Mortalities for neem oil and neem leaf extract ranged from 72.7% to 82% and 38% to 95.3%, respectively, with the greatest percentage of mortalities occurring at the lower concentrations. Neem oil and neem leaf extract can be used as alternative acaricides, and however, they are less efficacious against the brown dog tick than amitraz and fipronil.

    更新日期:2019-11-20
  • Pilot study assessing the possible benefits of a higher level of implementation of biosecurity measures on farm productivity and health status in Belgian cattle farms
    Transbound. Emerg. Dis. (IF 3.554) Pub Date : 2019-11-17
    Véronique Renault, Marc Lomba, Laurent Delooz, Stefaan Ribbens, Marie‐France Humblet, Claude Saegerman

    Over the last few years, the interest of decision‐makers and control agencies in biosecurity (BS), aiming at preventing and controlling the introduction and spread of infectious diseases, has considerably increased. Nevertheless, previous studies highlighted a low implementation level of biosecurity measures (BSM), especially in cattle farms; different reasons were identified such as perceived costs, utility, importance, increased workload and lack of knowledge. In order to convince cattle farmers to adopt BSM, it is necessary to gather more information and evidence on their cost‐effectiveness and their importance or utility in terms of disease prevention and control. The objectives of this study were to determine whether the farm or farmers’ profile correlated with the implementation level of BSM and if there was a positive correlation between the BSM implementation and the farm production and health parameters. Data were collected through face‐to‐face interviews conducted in 100 Belgian farms as part of a stratified and randomized survey. The Regional Animal Health Services provided the farm health status and production data. A general BS score and five sub‐scores related to the five BS compartments (bio‐exclusion, bio‐compartmentation, bio‐containment, bio‐prevention and bio‐preservation) were calculated for each farm based on the implementation level of different BSM grouped in 16 domains. The study highlighted a significant and negative correlation between the mortality rates in adult cattle (over 24 months of age) and young calves (aged 0–7 days) and different BS compartment scores. The study also demonstrated that the farms having a higher general BS score were indeed more likely to have a BVD‐free status. These evidence‐based findings are encouraging as they demonstrate the benefits of implementing BSM and could promote their adoption by farmers.

    更新日期:2019-11-18
  • Quantitative risk assessment of African swine fever virus introduction to Japan via pork products brought in air passengers’ luggage
    Transbound. Emerg. Dis. (IF 3.554) Pub Date : 2019-11-17
    Satoshi Ito, Cristina Jurado, José Manuel Sánchez‐Vizcaíno, Norikazu Isoda

    The spread of African swine fever (ASF) has reached pandemic levels over the last decade, and outbreaks of this disease in China, Mongolia, Vietnam and Cambodia in 2018 and 2019 could accelerate its transmission to neighbouring Asian territories. Thus, the risk that the ASF virus (ASFV) will be introduced to disease‐free territories increases each year. Since Japan is an island nation, the most likely way in which ASFV would be introduced is via pork products brought in air passengers’ luggage (PPAP). Therefore, in the present study, we assessed the risk of ASFV introduction to Japan via PPAP. For the purposes of this analysis, we considered 214 international commercial flights travelling from 47 origin territories to 31 destination airports as potential routes of ASFV introduction via PPAP. The risk was estimated quantitatively through a stochastic model that considered the volume of air passengers’ luggage, the amount of confiscated pork products that were carried in air passengers’ luggage and the disease status of the origin territory. The overall mean annual probability of ASFV introduction to Japan via PPAP was found to be 0.941 [95% confidence interval (CI), 0.661–1.000], which approximately corresponds to one introduction every 1.06 years. At the origin territory level, Mongolia was led as the highest risk territory, with a risk of 0.864 (95% CI, 0.434–1.000), followed by China (0.697; 0.223–0.999), Vietnam (0.662; 0.196–0.998) and the Russian Federation (0.136; 0.018–0.401). At the destination airport level, Narita International Airport had the highest risk (0.905; 0.537–1.000), followed by Kansai International Airport (0.496; 0.109–0.961), Tokyo International Airport (0.389; 0.072–0.879) and Chubu Centrair International Airport (0.338; 0.058–0.816). This information will help improve risk management activities and monitoring systems to prevent the introduction of ASFV to Japan.

    更新日期:2019-11-18
  • Characterization and genomic analysis of emerging astroviruses causing fatal gout in goslings
    Transbound. Emerg. Dis. (IF 3.554) Pub Date : 2019-11-17
    Qinxi Chen, Xin Xu, Zhengli Yu, Chaoge Sui, Kejing Zuo, Guanglin Zhi, Jun Ji, Lunguang Yao, Yunchao Kan, Yingzuo Bi, Qingmei Xie

    Since February 2017, severe outbreaks of fatal gout caused by novel gosling astroviruses (GoAstVs) have occurred in several Chinese provinces, causing a considerable economic impact on the poultry industry. To assess the infection status of GoAstVs causing gout, 165 clinical samples were collected from goslings from seven farms located in different Chinese provinces, and they were screened for viral infection. Seven GoAstV strains were completely sequenced. The positive infection rates of GoAstV, goose parvovirus, reovirus, goose haemorrhagic polyomavirus and Tembusu virus were 100%, 9.69%, 3.64%, 0% and 0%, respectively, indicating the role of GoAstV in gout. The genomes of all seven GoAstV strains were 7170‐nt long and encoded three open reading frames (ORFs), namely, ORF1a, ORF1b and ORF2. Sequence and phylogenetic analyses of the seven GoAstV strains showed that these were avastroviruses and were closely related to viruses classified within Avastrovirus 3 and turkey astrovirus 2. Moreover, the mutation rates of ORF1a and ORF2 were high, and ORF1a was highly mutated at amino acid loci 545–580. The tertiary structure of the mutated ORF2 protein was smooth, and its antigenic epitope was highly mutated, which may be related to the pathogenicity of the virus and caused by antibody pressure from the host. These findings enrich our understanding of the evolution of novel GoAstVs causing gout and their circulation as well as lay the foundation for the selection of vaccine strains.

    更新日期:2019-11-18
  • West Nile Virus spread and differential chemokine response in the central nervous system of mice: Role in pathogenic mechanisms of encephalitis
    Transbound. Emerg. Dis. (IF 3.554) Pub Date : 2019-11-15
    Beatriz Vidaña, Nicholas Johnson, Anthony R. Fooks, Pedro J. Sánchez‐Cordón, Daniel J. Hicks, Alejandro Nuñez

    West Nile virus (WNV) is a zoonotic mosquito‐borne flavivirus able to cause severe neurological disease in humans, horses and various avian species. The more severe pathological changes of neurotropic WNV infection are caused by virus neuroinvasion and/or the immunological response in the central nervous system (CNS). The extent in which inflammatory cell trafficking orchestrated by chemokines is involved in the pathogenesis of CNS lesions has not been entirely elucidated. To understand the sequence of pro‐inflammatory chemokine induction during WNV encephalitis, a murine intranasal inoculation model was used. The relationship between lesional patterns in the mice CNS, the viral antigen distribution and the expression of pro‐inflammatory chemokine (CCL2, CCL5 and CXCL10) were evaluated. Viral antigen was first observed in olfactory tract and pyriform cortex neurons, suggesting a retrograde neuronal infection from the olfactory nerve. A spatio‐temporal association between WNV antigen and perivascular cuffs development was observed. Chemokine immunostaining was widely distributed in the brain from early stages. CCL2 immunolabelling was localised in neurons, astrocytes, microglia and endothelial cells as well as mononuclear leucocytes within perivascular cuffs. In contrast, CCL5 and CXCL10 immunostaining were mainly observed in astroglia and neurons, respectively. A strong correlation was demonstrated between the presence of perivascular cuffs and CCL2 and CCL5 expression in most brain areas, while CXCL10 was only associated with inflammatory lesions in few specific regions. Importantly, a strong correlation between WNV and CCL5 distribution was observed. However, no correlation was observed between CXCL10 and viral antigen. Neurons were confirmed as the main target cells of WNV, as well as one of the sources of CCL2, CCL5 and CXCL10. This study shows the sequence and comparative distribution pattern between histological lesions, WNV antigen and chemokine expression over the infection process. Furthermore, it identifies potential targets for immune intervention to suppress damaging chemokine responses.

    更新日期:2019-11-17
  • Investigation of the molecular epizootiological characteristics and tracking of the geographical origins of Brucella canis strains in China
    Transbound. Emerg. Dis. (IF 3.554) Pub Date : 2019-11-15
    Zhi‐guo Liu, Heng Wang, Miao Wang, Zhen‐jun Li

    Brucellosis is a global pandemic infectious zoonosis. Brucella canis is a rare source of human brucellosis in China, and its public health significance remains under debate. Moreover, data pertaining to the epizootiological characteristics and geographical origin of B. canis on a nationwide scale are limited, and the risk to public safety posed by B. canis infections is unknown. The MLVA (multilocus variable‐number tandem repeat analysis) assay can be helpful to analyse epidemiological correlations among Brucella isolates and to track their geographic origins. To accomplish this task, MLVA‐16 was used to analyse the epidemiological links of 63 isolates obtained from dogs and humans. Sixty‐three B. canis strains were sorted into three large clusters (A, B and C) and 50 different genotypes (GT1–50), and 43 unique genotypes were represented by single isolates, suggesting that these strains had no obvious epidemiological links and that canine brucellosis is predominantly sporadic in China. The other seven shared genotypes (among a total of 20 isolates) were each represented by two to eight isolates, indicating that strains from each shared genotype were epidemiologically correlated. Five of the shared genotypes were from 16 strains obtained from Beijing, indicating that canine brucellosis in Beijing originates from multipoint outbreaks with multiple sources of infection. Based on comprehensive case analysis of clinical B. canis infection, we preliminarily suggest that human B. canis infections are associated with Mycoplasma pneumoniae infection that results in decreased patient immunity. B. canis may have limited epidemiological significance for the healthy population, but it remains a significant threat to the canine breeding industry and to humans who come into close contact with dogs. Based on MLVA‐11 data, B. canis strains were clustered into 16 genotypes and divided into five evolutionary branches; these data confirm that this population covers an extensive geographic area and exhibits characteristics of the origin and evolution of co‐existing introduced and locally native lineages. We believe this study will contribute to strengthening efforts to prevent and control canine brucellosis and to improve public understanding of the health risks posed by B. canis.

    更新日期:2019-11-17
  • Molecular epidemiology and phylogeny of spotted fever group Rickettsia in camels (Camelus dromedarius) and their infesting ticks from Tunisia
    Transbound. Emerg. Dis. (IF 3.554) Pub Date : 2019-11-15
    Rachid Selmi, Mourad Ben Said, Houcine Ben Yahia, Hedi Abdelaali, Lilia Messadi

    Rickettsia species are adapted to a wide range of specific animal hosts. Camels (Camelus dromedarius) have been identified as a carrier of various zoonotic pathogens and became a focus of growing public health interest. This study reported the occurrence of rickettsial infection in camels and infesting ticks from five Tunisian governorates. Based on ompB PCR, eight out of 293 camels (2.7%) were found to be infected with Rickettsia spp. Furthermore, 13 tick specimens of Hyalomma impeltatum (10.4%) and 9 of H. dromedarii (8.0%) harboured DNA of Rickettsia bacteria with an overall prevalence rate of 9.2% (22/237). Molecular prevalence of Rickettsia infection varied significantly according to tick infestation for camels and among tick genders. Five rickettsial species, showing a potential public health interest, were revealed by sequencing. Based on ompB partial sequences, five species were identified corresponding to R. aeschlimannii, R. monacensis, R. helvetica and R. massiliae in camels and to R. africae, R. aeschlimannii, R. monacensis and R. helvetica in ticks. Based on ompA typing, three species were revealed corresponding to R. africae and R. monacensis in camels and to R. africae, R. aeschlimannii and R. monacensis in ticks. This is the first report consolidating the hypothesis that camels may serve as potential hosts for Rickettsia spp. and Hyalomma spp. ticks as possible vectors in arid and Saharan areas of Tunisia. The present data highlight the importance of preventive measures and survey that must be implemented in camel herds in order to limit the spread of these vector‐borne bacteria to animals and humans.

    更新日期:2019-11-17
  • Prevalence of caprine brucellosis on herds of toba communities in Villa Río Bermejito, Chaco, Argentina (October 2010)
    Transbound. Emerg. Dis. (IF 3.554) Pub Date : 2019-11-14
    María Amalia Simonetti, José Luis Suárez, Patricia Rizzari

    The purpose of this study was to evaluate the prevalence of caprine brucellosis in goat herds in a region known as ‘The Impenetrable’ in Chaco Province, Argentina, in order to prevent the occurrence of the disease in people consuming goats’ milk. There are high levels of child malnutrition and difficulties in accessing high‐quality protein in this region; therefore, goats’ milk is a valuable nutrition source. We travelled with Patricia Sosa's foundation ‘Little gestures, big results’ to Villa Río Bermejito, Chaco, in October 2010 with the laboratory equipment needed to carry out field tests. The foundation is staffed by voluntary workers, including doctors, dentists, experts in social issues, psychologists, who encourage the community to consume goats’ milk in their meals after cooking or pasteurizing it to avoid contamination. Blood samples were taken from 273 goats distributed in 13 herds established in the depth of Chaco dry forest that had not been vaccinated against brucellosis. Samples were analysed using the buffered plate antigen test, and positive results were confirmed using the slow agglutination test. Animals were identified using small plastic ear tags. We found only one positive case, with a titre of 1/50. This was considered suspicious and the owner was advised to take the animal out of the herd. Our results indicate that the isolation of these herds in the depths of the forest has protected them from brucellosis, and therefore, they are a good source of high‐quality protein, which the people of this region need.

    更新日期:2019-11-15
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