JLE

Cahiers d'études et de recherches francophones / Santé

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Malaria in sub-Saharan Africa: a comparison of rural and urban areas Volume 1, issue 1, Avril 1991

Author
ORSTOM, 213, rue Lafayette, 75480 Paris Cedex 10, France.
  • Page(s) : 33-8
  • Published in: 1991

Malaria is transmitted by Anopheles, a mosquito with a two-stage life cycle (aquatic larvae and flying adults). Transmission is thus related to climatic patterns: as a result it is intensive all year round in equatorial areas, intensive and seasonal in sudanian areas and low and seasonal in sahalian areas. However, these differences in transmission rates are not reflected by parasitological and serological parameters or by the morbidity due to malaria in these areas. In contrast, there is a new ecological pattern emerging in Africa, with the growth of big cities: there will be more than 40 town with one million-plus inhabitant by the end of the century. The number of potentially infectious mosquito bites is lower than one per year per inhabitant. Parasitological and serological positivity rates are very low in both children and adults, and yet malaria is a major disease, with an incidence similar to that in rural areas. The apparent lack of correlation between transmission rates and morbidity has obvious implications for control programs.