Targeting mosquitoes to tackle malaria
Malaria death rates have fallen by more than 60% worldwide since the year 2000. Progress has been made possible, in large part, through the wide-scale deployment of effective vector control tools that target malaria-carrying mosquitoes – primarily long-lasting insecticidal nets (LLINs) and also indoor residual spraying (IRS). Despite these gains, several threats have the potential to weaken mosquito control efforts in many parts of the world.
Threats to effective malaria vector control
A number of challenges threaten to undermine the effectiveness of malaria vector control. These include: low coverage and poor-quality deployment of LLINs and IRS; behaviours that enable mosquitoes to avoid contact with these tools, such as feeding or resting outdoors; and mosquito resistance to insecticides. WHO tracks the status of such threats in order to guide countries in formulating an appropriate response.
A new publication from WHO presents a comprehensive overview of the extent of mosquito resistance worldwide. The Global report on insecticide resistance in malaria vectors: 2010-2016, released in May 2018, highlights widespread resistance across all malaria-endemic regions, particularly for the insecticides used in all LLINs and some IRS.
Though the impact of resistance on malaria burden is not yet fully known, it is clear that new and improved tools are needed to address this threat. Similarly, new approaches are needed to target mosquitoes that bite outdoors or otherwise avoid contact with LLINs and IRS.
While new tools are under development, WHO recommends the continued use of LLINs and IRS to protect populations at risk of malaria. Affected countries are encouraged to develop and apply insecticide resistance monitoring and management plans that leverage available tools appropriately, and incorporate proven new interventions once available.