Virus interferes with host-seeking behaviour of mosquito

Area of Science:

• Vector-borne disease ecology
• Pathogen-host interactions
• Neurobiology of insect behavior

Background:

• Vector-borne pathogen transmission relies on vector host-seeking behavior.
• Pathogens often manipulate vector behavior to enhance transmission.
• West Nile virus (WNV) primarily infects birds, with mammals as dead-end hosts.

Purpose of the Study:

• To investigate if WNV infection alters mosquito host-seeking behavior and host preference.
• To test the hypothesis that WNV enhances its transmission by increasing mosquito attraction to bird hosts.
• To determine if WNV infection affects mosquito fitness or sensory responses.

Main Methods:

• Mosquitoes infected with WNV were tested for host-seeking responses.
• Mosquitoes' antennal electrophysiological responses were measured.
• Mosquito fitness-related traits were assessed.

Main Results:

• WNV infection decreased, rather than increased, the mosquito's host-seeking response.
• No shift in mosquito host preference towards birds was observed.
• WNV infection did not affect mosquito fitness or antennal electrophysiological responsiveness.

Conclusions:

• WNV infection impairs mosquito host-seeking behavior, potentially due to central nervous system interference.
• This behavioral change does not favor WNV transmission, challenging the paradigm of pathogen-driven behavioral manipulation for enhanced spread.
• This study presents the first evidence of pathogen-induced behavioral changes that hinder, rather than promote, transmission.