Résumé
Since 1985, global warming has become a subject of concern for WHO. A meeting in Geneva in 1990 has stressed the risk of a malaria increase using mathematical models without field confirmed studies. Based on our field experience in East Africa and Madagascar, it appears that malaria increase is mainly dependent on the following factors: cancellation of vector control programs, rainfall abnormally heavy, changes of ground occupation and surface water, human exposure due to professional activities, and possibly temperature rise but in combination with other factors. On the contrary, malaria decrease was observed following the occurrence of vector control programs based on indoor house spraying using remnant effect insecticide, drought such as in Sahel, improvement of housing. Malaria is an increasing public health problem reinforced by the double resistance of parasites to anti-malarial drugs and mosquitoes to some insecticides. However, this trend could be inverted in unstable malaria regions, such as mountainous areas, by setting up appropriate vector control programs which implies a better knowledge of vector distribution and ecology.