Page Banner

United States Department of Agriculture

Agricultural Research Service

Research Project: COUNTERMEASURES TO PREVENT, MITIGATE, AND CONTROL RIFT VALLEY FEVER (RVF)

Location: Arthropod-Borne Animal Diseases Research

Title: Effect of environmental temperature on the vector competence of mosquitoes for Rift Valley fever virus

Authors
item Turell, Michael -
item Wilson, William

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: October 25, 2013
Publication Date: N/A

Interpretive Summary: Rift Valley fever is a mosquito-borne viral disease affecting small ruminants and cattle endemic in Sub-Saharan Africa. Infection is very lethal to newborn animals and can also result in abortions. Outbreaks occur when ideal environmental conditions occur favor mosquito transmission of the virus. This study describes how environmental temperature affects virus replication in mosquito species capable of transmitting the virus. This data is useful for risk assessment model predicting when an outbreak may occur.

Technical Abstract: Environmental temperature has been shown to affect the ability of mosquitoes to transmit numerous arboviruses and for Rift Valley fever virus (RVFV) in particular. We evaluated the effect of incubation temperatures ranging from 14-26ºC on infection, dissemination, and transmission rates for Culex tarsalis and Aedes taeniorhynchus allowed to feed on hamsters infected with RVFV. Engorged mosquitoes were randomly allocated to cages and placed in incubators maintained at 14, 18, 22, or 26ºC. While infection rates detected in Cx. tarsalis increased with increasing holding temperature, holding temperature had no effect on infection rates detected in Ae. taeniorhynchus. However, for both species, the percentage of mosquitoes with a disseminated infection after a particular extrinsic incubation period (7, 10, 14, 17, or 21 days) increased with increasing incubation holding temperature, even after adjusting for the apparent increase in infection rate in Cx. tarsalis. The effects of environmental factors, such as ambient temperature, need to be taken into account when developing models for viral persistence and spread in nature.

Last Modified: 10/30/2014
Footer Content Back to Top of Page