Pathogens spread by high-flying wind-borne mosquitoes

Area of Science:

• Vector-borne disease epidemiology
• Aerobiology and entomology
• Pathogen transmission dynamics

Background:

• Mosquito-borne diseases (e.g., malaria, dengue) cause significant global mortality.
• High-altitude wind-borne migration in mosquitoes is documented but its epidemiological role is unknown.
• The potential for long-distance pathogen spread by flying mosquitoes requires direct investigation.

Purpose of the Study:

• To test the hypothesis that high-flying mosquitoes spread pathogens over long distances.
• To investigate the epidemiological significance of mosquito high-altitude migration.
• To characterize the pathogen-vector aerial network in mosquito populations.

Main Methods:

• Collected 1,017 female mosquitoes using balloon-suspended nets at 120-290 m altitude in Mali and Ghana.
• Screened mosquitoes for arboviruses, Haemosporida (Plasmodium spp.), and filariae.
• Determined infection and infectiousness rates, and identified specific pathogens and mosquito species.

Main Results:

• 61 mosquito species, including Culex, Aedes, and Anopheles, were collected at high altitudes.
• Significant infection rates were found: Plasmodium spp. (7.2%), filariae (1.6%), and flaviviruses (3.5%).
• Twenty-one pathogens were identified, with disseminated infections in several species, confirming pathogen-carrying capacity.

Conclusions:

• High-flying mosquitoes are commonly infected with diverse pathogens, including arboviruses, protozoans, and helminths.
• Disseminated infections in high-altitude mosquitoes demonstrate their capacity to transmit pathogens over long distances.
• This aerial pathogen-vector network is crucial for maintaining sylvatic pathogens and initiating outbreaks in new locations.