ABSTRACT

Dengue is an important mosquito-borne viral disease in humans in tropical and subtropical countries. In 2019, a total of 6917 dengue cases were reported in Tanzania based on serological analysis. The aim of this study was to confirm the presence of dengue virus (DENV) and conduct its genetic characterization. A total of 191 serum samples were collected from the outpatients seeking care from health facilities in Kinondoni and Ilala districts between March and May 2019. All the samples were initially tested for the presence of non-structural protein 1 and anti-DENV immunoglobulin G (IgG) and IgM using a commercial OnSite Duo Dengue Ag-IgG/IgM rapid test. Of the 191 sera, 110 (57.6%) were DENV seropositive. The presence of DENV ribonucleic acid was confirmed in 18.2% of the seropositive sera by reverse transcription polymerase chain reaction (RT-PCR). The RT-PCR products were cleaned and partial sequences of DENV polyprotein gene determined using dideoxynucleotide cycle sequencing followed by phylogenetic analysis. We present the occurrence of DENV serotype 1 (DENV-1) during the 2019 outbreak in Tanzania. The DENV-1 strains reported in the present study are highly identical and cluster with Asian DENV-1 strains indicating the possibility of intercontinental spread of DENV through globalization. We advocate for the need for molecular surveillance of dengue viruses during outbreaks to provide rapid evidence of the disease to guide public health interventions.

摘要

登革热是热带和亚热带国家人类中一种重要的蚊媒病毒性疾病。根据血清学分析，2019年坦桑尼亚共报告登革热病例6917例。本研究的目的是确认登革热病毒 (DENV) 的存在并进行其遗传表征。2019 年 3 月至 5 月期间，从 Kinondoni 和 Ilala 地区的卫生机构就诊的门诊患者中收集了 191 份血清样本。所有样本最初都进行了非结构蛋白 1 和抗 DENV 免疫球蛋白 G（IgG ) 和 IgM 使用商业 OnSite Duo Dengue Ag-IgG/IgM 快速测试。在 191 份血清中，110 份（57.6%）为 DENV 血清阳性。通过逆转录聚合酶链式反应 (RT-PCR) 在 18.2% 的血清阳性血清中证实了 DENV 核糖核酸的存在。清洗 RT-PCR 产物并使用双脱氧核苷酸循环测序确定 DENV 多蛋白基因的部分序列，然后进行系统发育分析。我们介绍了 2019 年坦桑尼亚爆发期间 DENV 血清型 1 (DENV-1) 的发生情况。本研究报告的 DENV-1 毒株与亚洲 DENV-1 毒株高度相同，表明 DENV 通过全球化进行洲际传播的可能性。我们主张在爆发期间需要对登革热病毒进行分子监测，以提供该疾病的快速证据，以指导公共卫生干预措施。我们介绍了 2019 年坦桑尼亚爆发期间 DENV 血清型 1 (DENV-1) 的发生情况。本研究报告的 DENV-1 毒株与亚洲 DENV-1 毒株高度相同，表明 DENV 通过全球化进行洲际传播的可能性。我们主张在爆发期间需要对登革热病毒进行分子监测，以提供该疾病的快速证据，以指导公共卫生干预措施。我们介绍了 2019 年坦桑尼亚爆发期间 DENV 血清型 1 (DENV-1) 的发生情况。本研究报告的 DENV-1 菌株高度相同，并与亚洲 DENV-1 菌株聚集，表明 DENV 通过全球化进行洲际传播的可能性。我们主张在爆发期间需要对登革热病毒进行分子监测，以提供该疾病的快速证据，以指导公共卫生干预措施。