Climate and Malaria in Africa

Economic development has played an enormous role in shaping the current global distribution of malaria. Where malaria is not adequately controlled, however, its distribution and seasonality are closely related to seasonal characteristics of the climate.

Consequently, it may be found where and when the climatic conditions are favorable for transmission between the mosquito vector and its human host. Malaria is endemic throughout much of Sub-Saharan Africa and regularly affects susceptible populations each year. Within that endemic zone, however, the disease exhibits a spectrum of characteristics. Areas of stable endemicity where transmission occurs all year round exist at one extreme, while at the other extreme, there are areas where little or no transmission takes place most of the time but epidemics may occur among susceptible immunological native populations.

Along the margins of endemic malaria, there are geographic zones where malaria transmission is 'unstable' or prone to epidemics. Malaria in these areas is also related to climate, but in this case, at least one of the essential variables, precipitation, temperature or humidity, is not consistently sufficient for transmission. The high inter-annual variability of climate in these regions, however, means that in some years the climatic conditions favorable for malaria transmission do occur and epidemics of the disease may result.

These map rooms hold collections of products that may help predict malaria in certain situations. In many cases, background information is necessary to use the product data efficiently. Not every product will be useful for all situations. The mapping products aim to illustrate models of climate suitability for seasonal endemic malaria, and recent climate conditions, such as precipitation anomalies, which may be associated with epidemic malaria in warm semi-arid regions of Africa. Additional models, such as that developed by the MARA Initiative, may be included in the future and we welcome the opportunity to work with others on the further development of these products.

References: Grover-Kopec E. K., Blumenthal M. B., Ceccato P., Dinku T., Omumbo J. A., Connor S. J. Web-based climate information resources for malaria control in Africa. Malaria Journal. 2006, 5:38.

    The Malaria Early Warning System (MEWS) aids in the prediction of malaria outbreaks. The system consists of four elements; Vulnerability, Seasonal Climate Forecasts, Monitoring the Environment and Observed Malaria Morbidity. In certain regions, these products may be used to determine the timing and severity of an outbreak.
    Climate variables may effect malaria transmission in certain regions. These products aid to determine the historical risk for malaria due to climatic factors.