Assessing the role of two populations of Aedes japonicus japonicus for Zika virus transmission under a constant and a fluctuating temperature regime.

Abstract

Background Since the huge epidemic of Zika virus (ZIKV) in Brazil in 2015, questions were raised to understand which mosquito species could transmit the virus. Aedes aegypti has been described as the main vector. However, other Aedes species (e.g. Ae. albopictus and Ae. japonicus) proven to be competent for other Flaviviruses (e.g.West Nile, dengue and yellow fever), have been described as potential vector for ZIKV under laboratory conditions. To name one, the Asian bush mosquito Ae. japonicus which is widely distributed with high abundances in Central-Western Europe. In the present study, infection, dissemination and transmission rates of ZIKV (Dak84 strain) in two populations of Ae. japonicus from Switzerland (Zürich) and France (Steinbach, Haut-Rhin) were investigated under constant (27 °C) and fluctuating (14-27 °C, mean 23 °C) temperature regimes.Results The two populations were each able to transmit ZIKV under both temperature regimes. Infectious virus particles were detected in the saliva of females from both populations, regardless of the incubation temperature regime, from 7 days post exposure to infectious rabbit blood. The highest amount of Plaque Forming Unit (PFU) (400/ml) were recorded 14 days post oral infection in the Swiss population incubated at constant temperature. No difference in term of infection, dissemination and transmission rate were found between mosquito populations.Temperature had no effect on infection rate but the fluctuating temperature regime resulted in higher dissemination rates comparing to constant temperature, regardless of the population. Finally, transmission efficiency ranged between 7-23% and 7-10% for the constant temperature and 0-10% and 3-27% under fluctuating temperatures for the Swiss and the French populations, respectively.Conclusions This is the first work confirming vector competence for ZIKV of Ae. japonicus originating from Switzerland and France at realistic summer temperatures under laboratory conditions. Considering the continuous spread of this species in the northern part of Europe and its adaptation at cooler temperatures, preventative control measures should be adopted to prevent possible ZIKV epidemics.

Zika vector competence data reveals risks of outbreaks: the contribution of the European ZIKAlliance project

“…Another invasive species, Ae. japonicus also experimentally transmits the African ZIKV 47 . Native to East Asia, Ae.…”

“…Its high ability to become infected, and to a lower extent, to ensure viral dissemination and transmission, concomitantly to its human-biting behavior gives Ae. japonicus the status of being a competent vector of ZIKV 47,50 . These findings are however subject to caution, as the experimental design may not allow for generalization of our observations: Ae.…”

Global potential distribution of three underappreciated arboviruses vectors ( Aedes japonicus , Aedes vexans and Aedes vittatus ) under current and future climate conditions

“…j. japonicus (Turell et al., 2013), as up to 90% of all mosquitoes became infected and transmitted the virus within 7 days post‐infection. The species has been also described as potential vector for ZIKV under laboratory conditions in Germany, Netherlands, Switzerland, France and Japan (Abbo et al., 2020; Glavinic et al., 2020; Jansen et al., 2018; Uchida et al., 2021). The species was able to transmit ZIKV even under fluctuating (14−27°C, mean 23°C) temperature regimes (Glavinic et al., 2020).…”

Putative roles of mosquitoes (Culicidae) and biting midges (Culicoides spp.) as mechanical or biological vectors of lumpy skin disease virus

“…japonicus mosquitoes were collected with ovitraps in the field in the Zürich area (Switzerland) as described (Verhulst et al, 2020). Mosquitoes were reared according to standard protocols published earlier by our group (Glavinic et al, 2020; Verhulst et al, 2020; Wagner et al, 2018).…”