Climate risk management in Africa: Learning from practice
Malaria control in southern Africa Background Malaria is a huge burden in sub-Saharan Africa, causing between 1 and 3 million deaths each year as well as debilitating millions of others. It is a major impediment to development on the continent (Sachs and Malaney, 2002). The disease is caused by a parasite, Plasmodium, which is transmitted to people by mosquitoes. It is endemic throughout large regions of sub-Saharan Africa. In these endemic regions, conditions, including climate, are favorable for malaria transmission. At the geographical margins of these
Figure 8. Areas at risk of epidemic malaria in Africa. Source: Adapted from WHO/UNICEF (2003). Photo inset: Female Anopheles gambiae; WHO/TDR/Stammers
regions, there are areas where conditions are normally not favorable and malaria seldom occurs. However, from time to time conditions change briefly, and malaria becomes a threat, in the form of an epidemic. The changes are usually in climate conditions, and typically involve higher than normal rainfall in desert fringes (where it is normally too dry for malaria) and higher than normal temperatures in highland fringes (where it is normally too cool). Areas in Africa at risk of epidemic malaria are shown in Figure 8. Although endemic malaria is the major burden in sub-Saharan Africa, especially for children under 5 and pregnant women, epidemic malaria is also a significant problem (Worrall et al., 2004). An estimated 124 million Africans live in areas prone to epidemics, which cause between 12% and 15% of all malaria deaths. Because they are rarely exposed to the disease, people living outside endemic regions have low or no immunity, and all age groups are vulnerable. When an epidemic occurs, health services in these areas can easily be overwhelmed. Importantly, and rarely appreciated, endemic and epidemic malaria need different approaches to their control and prevention. Endemic malaria needs ongoing routine measures, whereas the control of epidemic malaria relies on measures being applied in the right place at the right time. This is
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