This contribution was provided by Dr. Christen Fornadel, Senior Malaria Vector Control Specialist at PMI.
The President’s Malaria Initiative (PMI) has made increasing investments in entomological monitoring across all 19 program countries in order to monitor the effects of two of PMI’s four main interventions, distribution of long-lasting, insecticide treated bed nets (LLINs) and indoor residual spraying (IRS), both of which are aimed at controlling mosquito populations. Both of these interventions are insecticide based, so as they are scaled up, one can expect to see changes in the species composition of the vector population and possibly changes in malaria mosquito behavior. But most importantly, we have already seen and are likely to continue to see changes in mosquito susceptibility to the insecticides used on LLINs and for IRS. As malaria vector control has escalated across Africa, so have the number of reports of pyrethroid resistance in both major vector groups, Anopheles gambiae s.l. and An funestus s.l., and today it is rare to find sites in Africa where one or both these vectors do not show some level of pyrethroid resistance. The global community spends hundreds of millions of dollars on malaria control, so it is important to make sure that we are doing entomological monitoring to see that our investments are making an impact, and that those resources are not wasted.