The Role of Vector Controls in the Fight Against Malaria

Working at Friends of the Global Fight Against AIDS, Tuberculosis and Malaria, we have the unique opportunity to speak with global health leaders from partner organizations all over the world. As part of our preparations for #WorldMalariaDay, we recently spoke with Dr. Dan Strickman from the Bill & Melinda Gates Foundation. As the Senior Program Officer for Vector Control, Dr. Strickman plays a crucial role in the Gates Foundation’s strategy for eliminating malaria, “Accelerate to Zero.” Our conversation illustrated the Foundation‘s comprehensive approach toward ensuring that we have the tools necessary to eradicate malaria.

The strategy surrounding vector control is threefold:

  • Preserve the gains that have already been made;
  • Develop new tools that attack mosquitoes in new ways; and
  • Use data to direct how these tools are implemented.

In the 2015 World Malaria Report, it was reported that of the 42 percent reduction in Africa’s malaria incidence rate since 2001, approximately 79 percent of that reduction was due to vector control methods including long-lasting insecticidal nets (LLINs) and indoor residual spraying (IRS). The gains from vector control measures are under persistent threat, however, from the development of insecticide resistance among mosquito populations. To counter this threat, the Gates Foundation has been working over the last 10 years to develop entirely new insecticides. This is particularly exciting because all previous insecticides used in global health efforts were originally developed for use in agriculture; such widespread use makes resistance develop more quickly.

The Innovative Vector Control Consortium (IVCC) plays a major role in these insecticide development efforts. The IVCC has been able to evaluate 4.5 million compounds to identify chemical classes that have the greatest potential to be safe, effective and inexpensive to manufacture. Within the last 18 months, there has been significant progress as the IVCC has been able to move toward the identification of individual prioritized molecules for development.

In addition to ensuring that LLINs and IRS remain effective, the Gates Foundation is also looking to develop new strategies that could help control mosquito populations, such as sugar baits and eave tubes. Dr. Strickman stated that it is possible to control mosquito populations by attracting them to sugar-based baits laced with an insecticide. This technique is advantageous because mosquitos ingest the insecticide directly, requiring smaller concentrations. It also allows developers to consider a wider range of insecticide candidates by eliminating the need for a chemical that can permeate a mosquito’s cuticle. Sugar baits are also promising because they target different segments of mosquito populations than existing interventions, as LLINs and IRS target mature female mosquitoes that come into contact with the insecticide as they look to feed indoors.

Eave tubes are also an exciting new project, and have only been developed in the last few years. They work by sealing the area between the top of a house’s walls and its roof, and installing the tubes within the sealant. This funnels any mosquitoes attempting to enter the house through the tubes, which contain an electrostatically treated screen holding minute particles of insecticide in solid form. This format presents mosquitoes with a very large dose of insecticide. Not only does this protect everyone in the house, whether they sleep under a net or not, but it also restricts a child’s access to the insecticide, helping to keep them safe from accidental exposure.

The final element in the Gates Foundation’s strategy is identifying the best practices for how to implement all of these vector control efforts. This element involves developing new ways of collecting and using data, including real-time monitoring to support interventions that can react to current needs and prevent crises before they begin. A focus on data can also help to make elimination campaigns more cost-efficient, and ultimately produce greater outcomes for those at risk.

World Malaria Day is an opportunity each year to reflect on the incredible progress that we have made, but also to take stock of the work that is still left to accomplish. By speaking with global health experts like Dr. Strickland and learning about developing technologies, we can clearly see how – with continued bipartisan support – this epidemic can be eradicated.