BACKGROUND Trypanosoma evansi is the causative agent of surra, a disease that occurs in many animal species. The disease is responsible for substantial losses in global production and can be fatal if not diagnosed early. This study aims to determine the prevalence of T. evansi in livestock, equids and dromedary camels in Palestine. METHODS Blood samples were collected during 2015-2017 from domesticated animals (n = 259 animals; 77% females and 23% males) including camels (n = 87), horses (n = 46), donkeys (n = 28), mules (n = 2), sheep (n = 49) and goats (n = 48) from eight districts: Ariha (Jericho), Nablus, Bethlehem, Deir Al Balah, Jenin, Rafah, Tubas, and Khan Yunis. Parasite prevalence was determined using PCR and blood smear microscopy. PCR-positive samples were further phylogenetically analyzed using DNA sequences of the 18S ribosomal RNA gene. RESULTS The overall infection prevalence was 18% (46/259). The positivity rates according to PCR and microscopy examination were 17% (45/259) and 2.7% (7/259), respectively. The infection rates were as follows: camels, 26/61 (30%); horses, 8/46 (17%); donkeys, 3/28 (11%); mules, 1/2 (50%); sheep, 2/42 (4%); and goats, 6/42 (13%). Phylogenetic analyses of the 18S rRNA gene showed that 24 positive T. evansi samples from Palestine formed a monophyletic cluster with seven T. evansi sequences from Africa, Asia and South America, and three T. brucei sequences from Africa retrieved from GenBank. The spatial analysis showed three statistically significant foci of T. evansi infection in Jenin, Tubas (P = 0.02) and Ariha (Jericho) (P = 0.04). No statistically significant foci were detected in the Gaza Strip. CONCLUSIONS To the best of our knowledge, this is the first confirmation of high levels of infection with T. evansi as a causative agent of surra in Palestine. Our study emphasizes the need for a stringent surveillance system and risk assessment studies as prerequisites for control measures. Further investigations focusing on vectors and evaluation of risk factors are needed.

中文翻译：

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埃文锥虫在巴勒斯坦牲畜中的患病率。

背景技术埃文氏锥虫是surra的病原体，surra是在许多动物物种中发生的疾病。这种疾病造成全球生产的大量损失，如果不及早诊断，可能致命。这项研究的目的是确定巴勒斯坦的牲畜，马科动物和单峰骆驼中的伊文氏锥虫流行率。方法2015-2017年期间从家畜（n = 259只动物; 77％的雌性和23％的雄性）采集的血液样本中，包括骆驼（n = 87），马（n = 46），驴（n = 28），mu n = 2），来自八个地区的绵羊（n = 49）和山羊（n = 48）：八个地区：Ariha（耶利哥），Nablus，伯利恒，Deir Al Balah，Jenin，Rafah，Tubas和Khan Yunis。使用PCR和血液涂片显微镜检查确定寄生虫患病率。使用18S核糖体RNA基因的DNA序列进一步对PCR阳性样品进行系统发育分析。结果总体感染率为18％（46/259）。根据PCR和显微镜检查的阳性率分别为17％（45/259）和2.7％（7/259）。感染率如下：骆驼26/61（30％）；马，8/46（17％）; 驴，3/28（11％）; 子1/2（50％）; 绵羊2/42（4％）; 山羊为6/42（13％）。对18S rRNA基因的系统进化分析表明，来自巴勒斯坦的24例阳性埃文氏菌样品形成了单系簇，其中有来自非洲，亚洲和南美的七个埃文氏菌序列以及从GenBank检索到的来自非洲的三个布鲁氏菌序列。空间分析表明，在杰宁，图巴斯（P = 0.02）和阿里哈（耶利乔）（P = 0.04）的埃文斯锥虫感染具有三个统计学意义。在加沙地带未发现有统计学意义的病灶。结论据我们所知，这首次证实埃文氏螺旋体是巴勒斯坦surra的致病因子，感染水平很高。我们的研究强调需要严格的监视系统和风险评估研究作为控制措施的前提。需要针对媒介和风险因素评估进行进一步研究。