gms | German Medical Science

Background: Elimination of human malaria parasites requires global interventions that can sustainably interrupt transmission. As part of the millennium development goals by 2015, substantial progress has been made during the last 12 years, with an estimated 3.3 million deaths averted (45% decrease worldwide), and about 90% of these were children under the age of five living in sub-Saharan Africa. Central to these gains has been the massive scale-up of two leading vector control chemical insecticide interventions against mosquito vectors, e.g. Long Lasting Insecticidal Nets (LLINs) and Indoor Residual Sprays (IRS). Nevertheless, these measures alone are not sufficient to stop transmission in large areas of tropical Africa where the entomological inoculation rate (EIR), the most direct measure of human exposure, can exceed 1000 infective bites/person/year.

Assumption: A failure to appreciate the biological complexities that allow vector populations to resist or evade interventions can substantially impede control efforts. In particular, major challenges that must be tackled in order to move from control to elimination include but are not limited to: (1) ecological and behavioral heterogeneity of Anopheles species, (2) rapid spread of vector resistance to insecticides, (3) misuse of available tools and (4) shortage of new vector control tools and strategies. Although insecticide resistance is already on track in 58 countries, much is needed to reveal its factual operational impact. Less frequently reported, but no less a threat to effective malaria vector control, are changes in the behavioral phenotypes expressed within individual vector species after implementation of LLINs and IRS, and weakness in human behavior in relation to rational use of control tools.

Conclusion: The goal of malaria elimination requires urgent strategic investment into development of new field measurement tools for surveying vector populations and their environmental conditions.