Centro Regional de Investigación en Salud Pública, Instituto Nacional de Salud Pública, Tapachula, Chiapas, México.
Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional, Unidad Monterrey, Apodaca, Nuevo León, México.
Trop Med Int Health. 2019 Nov;24(11):1311-1319. doi: 10.1111/tmi.13306. Epub 2019 Oct 8.
Aedes aegypti and Aedes albopictus are the main mosquito species responsible for dengue virus (DENV) transmission to humans in the tropical and subtropical regions of the world. The role of vertical transmission in the epidemiology of dengue and the maintenance of this arbovirus in nature during interepidemic periods remain poorly understood, and DENV vertical transmission could sustain the existence of virus reservoirs within Aedes populations.
Between April 2011 and October 2012, we monitored vertical transmission of DENV in Ae. aegypti and Ae. albopictus in 9 cities of 4 Mexican states. Aedes eggs were collected in ovitraps, then adults were reared under laboratory conditions and their heads were used to infect C6/36 cells. The presence of flavivirus was detected by immunofluorescence assays (IFA), and DENV infection was confirmed by RT-PCR.
About 96% of reared adults were Ae. aegypti and 4.0% were Ae. albopictus. No infection was detected in Ae. albopictus, whereas 54 of 713 (7.8%) of Ae. aegypti pools tested positive. A minimum infection rate (MIR) of 2.52 per 1000 mosquitoes was estimated for Ae. aegypti. DENV-1, DENV-2 & DENV-3 serotypes were detected even during interepidemic periods.
This study reports the evidence of vertical transmission of dengue virus with viral isolation and molecular confirmation in Ae. aegypti eggs collected in four endemic regions of Central and Southern Mexico. Vertical transmission may play a role as a reservoir mechanism during mosquito dormancy in interepidemic periods but with minor participation in transmission during epidemic periods.
埃及伊蚊和白纹伊蚊是世界热带和亚热带地区传播登革病毒（DENV）给人类的主要蚊种。垂直传播在登革热流行病学中的作用以及该虫媒病毒在流行间歇期如何在自然界中维持，这些仍了解甚少，DENV 的垂直传播可能在蚊群中维持病毒库的存在。
2011 年 4 月至 2012 年 10 月，我们在墨西哥 4 个州的 9 个城市监测了埃及伊蚊和白纹伊蚊的 DENV 垂直传播情况。在诱卵器中收集伊蚊卵，然后在实验室条件下饲养成蚊，并使用其头部感染 C6/36 细胞。通过免疫荧光法（IFA）检测黄病毒的存在，并用 RT-PCR 确认 DENV 感染。
饲养的成蚊中约 96%为埃及伊蚊，4.0%为白纹伊蚊。白纹伊蚊未检测到感染，而 713 个埃及伊蚊中 54 个池呈阳性。埃及伊蚊的最小感染率（MIR）估计为每 1000 只蚊子 2.52 只。即使在流行间歇期也检测到 DENV-1、DENV-2 和 DENV-3 血清型。
本研究报道了在墨西哥中南部四个流行地区采集的埃及伊蚊卵中，通过病毒分离和分子确证证实了登革热病毒垂直传播的证据。垂直传播可能在流行间歇期蚊子休眠时作为一种储存机制发挥作用，但在流行期对传播的参与程度较小。
