Vector-Borne Diseases Research Team, Virology Department, Animal and Plant Health Agency, Woodham Lane, Addlestone, KT15 3NB, Surrey, UK.
Microbiology Services Division, Public Health England, Porton Down, Wiltshire, UK.
Parasit Vectors. 2021 Nov 3;14(1):566. doi: 10.1186/s13071-021-05070-0.
A number of zoonotic mosquito-borne viruses have emerged in Europe in recent decades. Batai virus (BATV), a member of the genus Orthobunyavirus, is one example of a relatively newly emerged mosquito-borne virus, having been detected in mosquitoes and livestock. We conducted vector competency studies on three mosquito species at a low temperature to assess whether Aedes and Culex mosquito species are susceptible to infection with BATV.
Colonised lines of Aedes aegypti and Culex pipiens and a wild-caught species, Aedes detritus, were orally inoculated with BATV strain 53.2, originally isolated from mosquitoes trapped in Germany in 2009. Groups of blood-fed female mosquitoes were maintained at 20 °C for 7 or 14 days. Individual mosquitoes were screened for the presence of BATV in body, leg and saliva samples for evidence of infection, dissemination and transmission, respectively. BATV RNA was detected by reverse transcription-PCR, and positive results confirmed by virus isolation in Vero cells.
Aedes detritus was highly susceptible to BATV, with an infection prevalence of ≥ 80% at both measurement time points. Disseminated infections were recorded in 30.7-41.6% of Ae. detritus, and evidence of virus transmission with BATV in saliva samples (n = 1, days post-infection: 14) was observed. Relatively lower rates of infection for Ae. aegypti and Cx. pipiens were observed, with no evidence of virus dissemination or transmission at either time point.
This study shows that Ae. detritus may be a competent vector for BATV at 20 °C, whereas Ae. aegypti and Cx. pipiens were not competent. Critically, the extrinsic incubation period appears to be ≤ 7 days for Ae. detritus, which may increase the onward transmissibility potential of BATV in these populations.
近几十年来，一些人畜共患的蚊媒病毒在欧洲出现。Batai 病毒（BATV）是一种新兴的蚊媒病毒，属于正布尼亚病毒属，已在蚊子和牲畜中检测到。我们在低温下对三种蚊子进行了媒介效能研究，以评估埃及伊蚊和库蚊是否容易感染 BATV。
用 2009 年从德国捕获的蚊子中分离出的 BATV 株 53.2 对经人工饲养的埃及伊蚊和库蚊以及野生捕获的 Aedes detritus 进行经口接种。饱血的雌性蚊子在 20°C 下饲养 7 或 14 天。分别对个体蚊子的身体、腿部和唾液样本进行 BATV 检测，以确定感染、传播和传播情况。通过逆转录-PCR 检测 BATV RNA，并用 Vero 细胞分离病毒进行阳性结果确认。
Aedes detritus 对 BATV 高度易感，两个测量时间点的感染率均≥80%。在 Ae. detritus 中记录到 30.7-41.6%的传播感染，在感染后 14 天的唾液样本中观察到 BATV 的病毒传播证据（n=1）。Ae. aegypti 和 Cx. pipiens 的感染率相对较低，在两个时间点均未发现病毒传播或传播。
本研究表明，在 20°C 时 Ae. detritus 可能是 BATV 的有效媒介，而 Ae. aegypti 和 Cx. pipiens 则不是。至关重要的是，Aedes detritus 的外潜伏期似乎≤7 天，这可能会增加这些种群中 BATV 的传播潜力。
