Maproom Climate and Health
Climate and Health Malaria

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, rainfall, 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.

The mapping products below therefore aim to illustrate models of climate suitability for seasonal endemic malaria, and recent climate conditions, such as rainfall 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.

Epidemic Malaria
Malaria Early Warning System
The Malaria Early Warning System (MEWS) consists of an integrated framework that utilizes climate forecasting and environmental monitoring products in order to provide warning to a potential outbreak of malaria (DaSilva et al., 2004). Precipitation is one of the essential elements of MEWS.
Rainfall Estimate Differences
This map shows dekadal (10-day) rainfall estimates as the difference from the short term average (from 2000 to last recent complete year). Positive (negative) values indicate dekadal estimates that are above (below) the short-term average rainfall.
Rainfall Estimate Percentages
This map shows dekadal (10-day) rainfall estimates as a percentage of the short term average (from 2000 to last complete year). Values greater (less) than 100% therefore indicate dekadal estimates that are above (below) the short-term average rainfall.
Minimum Land Surface Temperature (LST)
The Malaria Early Warning System (MEWS) consists of an integrated framework that utilizes climate forecasting and environmental monitoring products in order to provide warning to a potential outbreak of malaria (DaSilva et al., 2004).
Inferred Maximum Air Temperature at 2m
The map shows inferred maximum air temperature, one important component for the transmission of malaria (Ceccato et el., 2010). The black points on the map indicate locations of weather stations.
MODIS Analysis Tool
The Moderate Resolution Imaging Spectrometer (MODIS) Analysis Tool allows for maps of estimated vegetation to be produced. Two vegetation indices are provided: NDVI, EVI in addition to the reflectance values for the blue, red, near infrared and middle infrared channels. Images are available for western Africa, eastern Africa and southern Africa.
Country-Average WASP Index
This plot shows the time series of a country’s 12-month Weighted Anomaly Standardization Precipitation (WASP) index relative to a baseline period. The purpose of this tool is to provide a simple visual means of relating country-averaged precipitation to a reference period of interest.
Vectorial Capacity
The Malaria Early Warning System (MEWS) consists of an integrated framework that utilizes climate forecasting and environmental monitoring products in order to provide warning to a potential outbreak of malaria (DaSilva et al., 2004).
Endemic Malaria
Seasonal Climatic Suitability for Malaria Transmission
This map shows the number of months suitable for malaria transmission, based on climatological averages. Suitability is defined as the coincidence of precipitation accumulation greater than 80 mm, mean temperature between 18°C and 32°C, and relative humidity greater than 60%.
MARA Distribution Model of Climatic Suitability for Malaria Transmission
This map shows climatic suitability for malaria transmission based on the MARA (Mapping Malaria Risk in Africa) distribution model.
Malaria Atlas Project (MAP) Maps of Malaria Transmission and Endemicity
The Malaria Atlas Project (MAP) has constructed a global database and atlas of maps that show the spatial limits of Plasmodium falciparum transmission based upon parasite rate surveys, the predicted spatial distribution of Plasmodium falciparum malaria endemicity, and the model uncertainty for the predicted endemicity.