Comparing the Effectiveness of Malaria Vector-Control Interventions Through a Mathematical Model

Abstract

Although some malaria-control programs are beginning to combine insecticide-treated nets (ITNs) and indoor residual spraying (IRS), little is known about the effectiveness of such combinations. We use a mathematical model to compare the effectiveness of ITNs and IRS with dichlorodiphenyltrichloroethane (DDT) or bendiocarb, applied singly and in combination, in an epidemiological setting based in Namawala, Tanzania, with Anopheles gambiae as the primary vector. Our model indicates that although both IRS (with DDT) and ITNs provide personal protection, humans with only ITNs are better protected than those with only IRS, and suggests that high coverage of IRS with bendiocarb may interrupt transmission, as can simultaneous high coverage of ITNs and IRS with DDT. When adding a second vector-control intervention, it is more effective to cover the unprotected population first. Although our model includes some assumptions and approximations that remain to be addressed, these findings should be useful for prioritizing and designing future field research.

Efficacy of indoor residual spraying with dichlorodiphenyltrichloroethane against malaria in Gambian communities with high usage of long-lasting insecticidal mosquito nets: a cluster-randomised controlled trial

“…Some models indicate that LLIN and IRS combined would interrupt transmission in areas of moderate transmission 7,8 . Yet others suggest that the impacts could be antagonistic against the major African vectors: Anopheles gambiae s.s. 9 and A arabiensis 10 .…”

Landscape Epidemiology Modeling Using an Agent-Based Model and a Geographic Information System

“…Both interventions have been extensively used as intervention tactics to reduce and control malaria in sub-Saharan Africa, as reported by numerous early and recent studies [37,39,41,43]. LSM (also known as source reduction) is one of the oldest tools in the fight against malaria.…”

“…These interventions are often applied in isolation and in combination, and their impacts have been investigated by numerous early and recent studies [38][39][40][41][42][43][44][45]. In addition to these time-tested, established tools, new and novel intervention tactics and strategies such as new drugs, vaccines, insecticides, improved surveillance methods, etc., are also being investigated [46].…”

Highlights of a Symposium, Malaria: Where are we Today, Where are we Going?

“…However, these models contain many assumptions and need adaptations based on more field data [43]. Sequencing of the A. gambiae genome has provided insight into the vector's biological processes.…”

“…Of all adults (15,166) and children (43,130) It was shown that bloodstream infections are common in Africa and associated with high mortality. In nine studies involving 11,814 patients where both bacteremia and parasitemia were taken into account, 6.5% of patients who had parasitemia also had bacteremia.…”