Zika virus (ZIKV) is a mosquito-borne orthoflavivirus that causes acute symptoms, such as fever and conjunctivitis. Aedes (Stegomyia) aegypti and Ae. (Stg.) albopictus are the primary and secondary vectors, respectively, although other Aedes species may also transmit ZIKV. Aedes (Ochlerotatus) japonicus, native to East Asia, has recently spread to North America and Europe; however, its potential in ZIKV transmission, particularly in Japanese populations, remains unclear. In our previous study, a low viral titer of ZIKV was detected in a single virus-challenged Ae. japonicus individual. In the present study, we increased the sample size and compared infection rates and viral titers among Ae. japonicus, Ae. aegypti, and Ae. albopictus following exposure to the ZIKV strain MR766. Cumulative infection rates of Ae. japonicus (18%) were lower than those of Ae. aegypti (71%) and Ae. albopictus (67%). Nonetheless, some Ae. japonicus individuals had higher viral titers than the challenge dose, indicating efficient replication. ZIKV RNA was also detected in 14% of the saliva samples at 10 days post-infection. These findings suggested that the Japanese population of Ae. japonicus could potentially serve as a vector.
Uchida et al. (Thu,) studied this question.