Weather and climate are major determinants of the geographical distribution, seasonality, year-to-year variability and longer term trends of malaria. Periods of long-term drought can reduce transmission. Periods of unusually high rainfall, altered humidity or warmer temperatures can result in modified distribution and duration of malaria, as well as icreased transmission, even in areas where control is strong. Natural climate variability – including the El Niño phenomena and other long-term meteorological cycles – are important not only in explaining trends in disease burden but also periodic upsurges in cases, including atypical epidemics.
The Intergovernmental Panel on Climate Change (IPCC) has concluded that anticipated changes in temperature and rainfall will affect the natural habitats of mosquitoes, changing the prevalence of the vector or prolonging transmission seasons (or both) in some areas, and potentially exposing new regions and populations to malaria and other vector-borne diseases.
This fact sheet was written to accompany the Briefing Paper Lessons learned from responding to malaria globally: A prototype for sustainable development.