Vertical Transmission of Zika Virus by Jiegao and Mengding Aedes aegypti (Diptera: Culicidae) Strains in Yunnan Province in China.

Zika virus (ZIKV) is a mosquito-borne pathogen classified in the genus Flavivirus of the family Flaviviridae. Vertical transmission is considered to be the primary way to maintain some arboviruses under adverse natural conditions, which play a critical epidemiological role in arbovirus spread and maintenance. Aedes aegypti is the primary vector for ZIKV. In this study, we demonstrated vertical transmission in two Ae. aegypti strains from Jiegao (JG) and Mengding (MD) in the border area of Yunnan province. The minimum infection rate of F1 adult progeny from JG Ae. aegypti strain was significantly higher than that of MD Ae. aegypti strain in the second gonotrophic cycle (1:14.29 and 1:200, respectively, p < 0.05). The cytopathic effect was observed in C6/36 cells after infection of ZIKV isolated from the progeny. The results suggest that Ae. aegypti mosquitoes from JG and MD play potential roles in ZIKV spread and maintenance. Therefore, more adult and eggs control methods should be implemented to control mosquitoes if a Zika epidemic occurs.