Pôle de Zoologie Médicale, Institut Pasteur de Dakar, 36 Avenue Pasteur, BP 220, Dakar, Senegal.
Pôle de Virologie, Institut Pasteur de Dakar, 36 Avenue Pasteur, BP 220, Dakar, Senegal.
BMC Microbiol. 2020 Jun 26;20(1):181. doi: 10.1186/s12866-020-01866-9.
Chikungunya (CHIKV), yellow fever (YFV) and Zika (ZIKV) viruses circulate in sylvatic transmission cycles in southeastern Senegal, where they share common hosts and vectors. All three viruses undergo periodic amplifications, during which they are detected in mosquitoes and sometimes in hosts. However, little is known about their spatio-temporal patterns in years in which they undergo concurrent amplification. The aim of this study was to describe the co-amplification of ZIKV, CHIKV, and YFV, and the daily dynamics of these arboviruses and theirs vectors within villages in southeastern Senegal.
Mosquitoes were collected monthly from July to December 2015. Each evening, from 6 to 9 PM, landing collections were performed by teams of 3 persons working simultaneously in 70 sites situated in forest (canopy and ground), savannah, agriculture, barren, and village (indoor and outdoor) land covers. Collections within villages were continued until 6 AM. Mosquitoes were tested for virus infection by virus isolation and RT-PCR. Seventy-five mosquito pools comprising 10 mosquito species contained at least one virus. Ae. furcifer and Ae. luteocephalus were infected by all three viruses, Ae. taylori by YFV and ZIKV, and remaining seven species by only, only YFV or only ZIKV. No single mosquito pool contained more than one virus. CHIKV was the only virus detected in all land cover classes and was found in the greatest number of sampling sites (32.9%, n = 70). The proportion of sites in which more than one virus was detected was less than 6%. Ae. aegypti formosus, Ae. furcifer, Ae. luteocephalus, Ae. minutus, Ae. vittatus, and An. gambiae were found within villages. These vectors were mainly active around dusk but Ae. furcifer was collected until dawn. All viruses save ZIKV were detected indoors and outdoors, mainly around dusk. Virus positive pools were detected over 2, 3 and 4 months for YFV, CHIKV and ZIKV, respectively.
Our data indicate that the distribution of different vector species and different arboviruses vary substantially between sites, suggesting that CHIKV, YFV, and ZIKV may have different transmission cycles in Southeastern Senegal.
基孔肯雅热（CHIKV）、黄热病（YFV）和寨卡（ZIKV）病毒在塞内加尔东南部的森林传播周期中循环传播，这些病毒在这些地区共享共同的宿主和媒介。所有这三种病毒都会定期扩增，在此期间，它们会在蚊子体内以及有时在宿主体内被检测到。然而，对于它们在同时发生扩增的年份中的时空模式，人们知之甚少。本研究旨在描述 ZIKV、CHIKV 和 YFV 的共同扩增，以及这些虫媒病毒及其在塞内加尔东南部村庄内的媒介的日动态。
2015 年 7 月至 12 月，每月采集蚊子。每晚 6 点至 9 点，由 3 人组成的小组同时在森林（树冠和地面）、热带稀树草原、农业、荒地和村庄（室内和室外）等 70 个地点进行降落采集。在村庄内的采集一直持续到早上 6 点。通过病毒分离和 RT-PCR 检测蚊子的病毒感染情况。含有至少一种病毒的 75 个蚊子群共包含 10 种蚊子。Ae. furcifer 和 Ae. luteocephalus 被三种病毒感染，Ae. taylori 被 YFV 和 ZIKV 感染，其余七种仅被 YFV 或 ZIKV 感染。没有一个蚊子群同时含有多种病毒。CHIKV 是所有土地覆盖类型中唯一检测到的病毒，并且在最多的采样点（32.9%，n=70）中发现。检测到多种病毒的采样点比例小于 6%。Ae. aegypti formosus、Ae. furcifer、Ae. luteocephalus、Ae. minutus、Ae. vittatus 和 An. gambiae 都在村庄内发现。这些媒介主要在黄昏时分活动，但 Ae. furcifer 一直采集到黎明。除 ZIKV 外，所有病毒都在室内和室外检测到，主要在黄昏时分。YFV、CHIKV 和 ZIKV 的阳性蚊子群分别检测到持续 2、3 和 4 个月。
我们的数据表明，不同媒介物种和不同虫媒病毒的分布在不同地点之间存在很大差异，这表明 CHIKV、YFV 和 ZIKV 在塞内加尔东南部可能具有不同的传播周期。
