Fernanda Zermoglio is the Adaptation and Vulnerability Specialist for the ATLAS project.
Shifting Burdens: Malaria risks in a hotter Africa
June 12, 2019
Sadie J. Ryan
Malaria is a treatable and preventable disease, yet malaria kills one child every 30 seconds, or about 3000 children every day. Nearly 92 percent of these cases occur in Africa. The disease is also costly, with estimates suggesting a malaria “penalty” of 0.5-9 percent per year to many countries’ gross domestic product. In 2017 alone, more than $2.2 billion in investments were made in support of malaria control and elimination efforts in sub-Saharan Africa. As the climate warms, these numbers are expected to increase.
The potential impacts of increased temperature on malaria burden are too great to be ignored. Malaria transmission is directly related to climate. Like most cold-blooded animals, the malaria parasite-carrying mosquito’s life cycle is tightly tied to temperature and affects reproduction rates and biting behavior. Call it the “goldilocks principle” – the mosquito/parasite combination can survive and reproduce only if the temperatures are just right. Too hot, and they overheat and either die or become ineffective transmitters of the disease; too cold, and they freeze.
The study points to important changes in malaria seasonality at a regional scale that must be addressed to safeguard people from the risks of the disease.
At the May Adaptation Community Meeting, the USAID-funded Adaptation Thought Leadership and Assessment (ATLAS) project presented findings from its latest report, Shifting Burdens: Malaria Risks in a Hotter Africa. The report uses these principles to model when and where rising temperatures will alter the distribution of habitat suitable for malaria-transmitting mosquitoes across the African continent, with important implications for how and where to program malaria control interventions. The report offers estimates on the influence of these changes to the number of people at risk by the 2030s, 2050s, and 2080s across sub-Saharan Africa.
Highlights of findings point to the fact that:
- As temperatures rise, new challenges to prevent and treat malaria across the continent will emerge.
- By 2030, increased temperatures will likely put roughly 22-36 million additional people at risk from exposure to malaria, especially in areas where temperature has previously limited the disease. Therefore people’s low immunity could lead to new outbreaks.
Projecting a rise in average temperatures in sub-Saharan Africa of 0.9°C by the 2030s and 4.5°C by the 2050s, the study points to important changes in malaria seasonality at a regional scale that must be addressed to safeguard people from the risks of the disease. There are many examples across sub-Saharan Africa where investments have shown marked progress in malaria control strategies. However, these gains could be compromised if future investments do not consider the role of rising temperatures in changes to epidemiology.
Shifting malaria burdens under a changing climate challenge traditional prevention and control investment strategies. The report offers critical insight on how to address changes brought about by a warmer climate, creating opportunities to avoid the worst outbreaks through improved planning and response, including investment in detailed geographical targeting and seasonal alignment of control efforts.
Dr. Sadie J. Ryan is an Associate Professor of Medical Geography at the University of Florida, and Principal Investigator of the Quantitative Disease Ecology and Conservation (QDEC) Lab group.