Massive irrigation projects in Africa are turning malaria into a year-round threat by killing off the 'dry season' that used to stop it.
March 24, 2026
Original Paper
Proximity to Irrigation Increases Mosquito Biting Risk in An Area Subject to Agricultural Expansion in Southern Malawi
SSRN · 6446223
The Takeaway
While irrigation is built to improve rural health and wealth, this study found it creates a 21-fold increase in mosquito biting risk. By providing a permanent water source, these systems eliminate the natural seasonal break that usually crashes mosquito populations, turning a seasonal illness into a perpetual presence.
From the abstract
Background: Southern Malawi is endemic for malaria and faces evolving transmission risks with the construction of a large-scale agriculture irrigation system under the Shire Valley Transformation Project (SVTP). To understand how the SVTP irrigation will affect mosquito-biting risk in the area, we conducted longitudinal entomological surveillance across three communities that differ in ecology, hydrology and distance from existing irrigation.<br><br>Methods: Over 20 months, mosquitoes were colle