This mosquito larval habitat in Kilifi, Kenya, is also used for domestic purposes such as washing.

“We had a hypothesis that since scents travel down wind, that the mosquitos were actually tacking across the wind until they found one of those odor plumes and then tacking upwind until they found it. We should expect to find that places with higher risk were upwind of larval habitat.”

Smith and his research team studied 642 children living in Kenyan villages after the rainy season, when malaria peaks.

Janet Midega is a medical entomologist with the Kenya Medical Research Institute and co-author of the study. She says scientists compared the malaria case data with the proximity of stagnant water pools. “What we did find was a lot of the pools of water did have immature mosquito stages, and so we sampled these pools of water. We sampled these mosquitos and identified them as the mosquito species that is responsible for malaria transmission in the area.”

The study found that the shorter the distance from those larval incubators, the higher the prevalence of malaria.

Smith says factoring wind into the equation makes it possible to target larval pools downwind from malaria hotspots and so control the disease at its source.

“And the philosophy here is just that knowing it better we might be able to predict the distribution of risk a little bit better, or at least understand what mosquitos are doing so that we can do a better job of distributing nets or interventions.”