Entomological monitoring

The U.S. President’s Malaria Initiative (PMI) delivers vector control interventions and protects millions of people against malaria through its PMI Evolve Project. An integral part of the project is the collection of robust entomological surveillance data to identify which mosquitoes are vectors of malaria, the relative geographical and temporal distribution and abundance of these mosquitoes, and their feeding and resting habits. This data is crucial to assessing the impact of vector control interventions on mosquito population and behavior. When evaluating indoor residual spraying (IRS), for example, PMI Evolve monitors the quality of the spraying as well as the length of time that insecticides sprayed remain effective. ITNs are evaluated for their insecticide effectiveness over their lifespan. The project also performs a series of tests to determine which insecticides are effective against the target mosquito population. These insecticide resistance data are consolidated for the World Malaria Report and the Vector Insecticide Resistance app in the Malaria Threats Map.

Entomological data needs to be aggregated and managed at a level that is informative for local vector control interventions. The ability to collect these data in hard-to-reach locations can be restricted by national malaria program capacity and a shortage or attrition of trained professionals. Community-based entomological surveillance (CBS) presents an opportunity to increase data collection and sample sizes in remote regions and to fill gaps in capacity needs, in a way that may be more sustainable than conventional approaches. PMI Evolve supports the training of local community members in the skills needed to conduct CBS.

One of the biggest threats to progress in fighting malaria has been the spread of an invasive mosquito species, Anopheles stephensi in Africa. While many mosquitoes commonly found in African countries thrive in rural areas during the rainy season, Anopheles stephensi can survive through dry periods and in urban areas. So vector control tools used in the past may not be as effective against this mosquito. It is estimated that as this species continues to spread, it could put an additional 126 million people in urban areas at risk of malaria. PMI is exploring new tools and approaches to mitigate its impact as it supports countries to respond to this threat.