Abstract

BackgroundOutbreaks of West Nile virus (WNV) have not occurred in northern Europe despite nearby circulation of WNV in the southern part of the continent. The main vector for WNV, the mosquito Culex (Cx.) pipiens, consists of two behaviorally distinct biotypes, pipiens and molestus, which can form hybrids. Although temperature has been shown to influence vector competence of Cx. pipiens for WNV and biotypes are differentially susceptible towards infection, the interaction between the two has not been elucidated.MethodsWe determined vector competence of the Cx. pipiens biotypes and hybrids, after 14 days of incubation at 18, 23 and 28 °C. Mosquitoes were orally infected by providing an infectious blood meal or by injecting WNV directly in the thorax. Infection and transmission rates were determined by testing the bodies and saliva for WNV presence. In addition, titers of mosquitoes with WNV-positive bodies and saliva samples were determined.ResultsOrally infected biotype pipiens and hybrids showed significantly increased transmission rates with higher temperatures, up to 32 and 14 %, respectively. In contrast, the molestus biotype had an overall transmission rate of 10 %, which did not increase with temperature. All mosquitoes that were infected via WNV injections had (close to) 100 % infection and transmission rates, suggesting an important role of the mosquito midgut barrier. We found no effect of increasing temperature on viral titers.ConclusionsTemperature differentially affected vector competence of the Cx. pipiens biotypes. This shows the importance of accounting for biotype-by-temperature interactions, which influence the outcomes of vector competence studies. Vector competence studies with Cx. pipiens mosquitoes differentiated to the biotype level are essential for proper WNV risk assessments.Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-016-1677-0) contains supplementary material, which is available to authorized users.

Highlights

  • Outbreaks of West Nile virus (WNV) have not occurred in northern Europe despite nearby circulation of WNV in the southern part of the continent

  • To determine the minimum incubation period until peak viral titers were reached, viral titers were assessed for Cx. pipiens biotype pipiens females up to 35 days postWNV infection (Additional file 1: Table S1)

  • Infection and transmission rates were determined for orally infected biotype pipiens, biotype molestus, and hybrid females after 14 days of incubation at 18, 23 or 28 °

Read more

Summary

Introduction

Outbreaks of West Nile virus (WNV) have not occurred in northern Europe despite nearby circulation of WNV in the southern part of the continent. American passeriform bird species are the main hosts for WNV, with the family of the corvids (Corvidae) being highly susceptible [8, 10,11,12]. Compared to North America, WNV-associated death rates among birds in Vogels et al Parasites & Vectors (2016) 9:393 southern Europe have been relatively low. It has, been hypothesized that European bird species are less susceptible to WNV compared to their North American counterparts. That three important bird species originating from Europe, the carrion crow, European jackdaw, and house sparrow, are highly susceptible to WNV [4, 5, 13]

Objectives
Methods
Results
Conclusion
Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.