Isotopic evidence that aestivation allows malaria mosquitoes to persist through the dry season in the Sahel

Tuesday, November 15, 2022

2:00 PM – 2:20 PM PT

Location: Vancouver Convention Centre, Meeting Room 221/222

Presenting Author(s)

Roy Faiman

Senior Scientist
National Institute of Allergy and Infectious Diseases
Rockville, Maryland

Co-Author(s)

AY

Alpha-Seydou Yaro

University of Sciences, Techniques and Technologies
Bamako, Bamako, Mali

Co-author(s)

AD

Adama Dao

University of Sciences, Techniques and Technologies
Bamako, Bamako, Mali
ZS

Zana Sanogo

Malaria Research and Training Center
Bamako, Bamako, Mali
MD

Moussa Diallo

University of Sciences, Techniques and Technologies
Bamako, Bamako, Mali
DS

Djibril Samake

International Center for Excellence in Research
Bamako, Bamako, Mali
OY

Ousmane Yossi

University of Sciences, Techniques and Technologies
Bamako, Bamako, Mali
LV

Laura Veru

National Institutes of Heath
Rockville, Maryland
LG

Leland Graber

Cornell University
Ithaca, New York

Data suggests that the malaria vector mosquito Anopheles coluzzii persists during the dry season in the Sahel through a dormancy mechanism known as aestivation; however, the contribution of aestivation compared to alternative strategies such as migration is unknown. Here, we marked larval Anopheles mosquitoes in two Sahelian villages in Mali using deuterium (2H) to assess the contribution of aestivation to persistence of mosquitoes through the seven-month dry season. After an initial enrichment period, 33% of An. coluzzii mosquitoes were strongly marked. Seven months following enrichment, multiple analysis methods supported the ongoing presence of marked mosquitoes, compatible with the prediction that the fraction of marked mosquitoes should remain stable throughout the dry season if local aestivation is occurring. The results suggest that aestivation is a major persistence mechanism of An. coluzzii in the Sahel, contributing at least 20% of the adults at the onset of rains. This persistence strategy could influence mosquito control and malaria elimination campaigns.