A Pilot Expert Elicitation to Assess the Risks of Malaria Vector Control Strategies in East Africa

Perhaps no other issue has divided the environmental and health communities as much as DDT. The re-introduction of DDT in several East African countries, as well as the demand for evidence-based policy, has led researchers at Duke University to develop the Malaria Decision Analysis Support Tool (MDAST). One facet of the MDAST is to assess the economic, environmental, and human health risks associated with alternative strategies for managing malaria. In this pilot survey and elicitation, risks are assessed for the two most commonly used vector control strategies – indoor residual spraying and insecticide-treated bednets – in Uganda, Tanzania, and Kenya. The elicitation encompasses a broad range of hazard pathways and risks, including harm to nontarget species, agricultural trade restrictions, and vector resistance, some of which are frequently neglected in the policy debate. Preliminary results from the survey indicate that decision-makers are highly concerned with the emergence of vector resistance from ITNs, IRS with DDT, and IRS with ICON. High levels of concern were present for all additional risks associated with DDT, including human health impacts, environmental impacts, and trade restrictions. Results from the elicitation revealed that experts assessing harm to nontarget species and the potential for trade restrictions attributed the highest level of risk to mismanagement of DDT and ICON. Results from the elicitation for vector resistance were even more alarming; the expert assessed high risks of the potential for vector resistance to occur from all pathways associated with permethrin-treated bednets and IRS with DDT. Again, high risks were attributed to mismanagement of DDT and ICON, indicating that mismanagement of insecticides is the riskiest pathway of exposure.