MALARIA AND CLIMATE - SENSITIVITY OF MALARIA POTENTIAL TRANSMISSION TO CLIMATE

Malaria, according to the World Health Organization, is one of the mos t serious and complex health problems facing humanity in the 20th cent ury. In the past, climatic changes have greatly affected its geography . Its seriousness and complexity are therefore likely to be compounded by an anthropogenic greenhouse effect. The Malaria Potential Occurren ce Zone (MOZ) model was designed to calculate first-order estimates of climate change impacts on malaria. MOZ focuses on the climatic determ inants of the life cycles of malaria parasites and vectors. It does no t take epidemiology into account. MOZ predicts receptivity, or potenti al transmission, rather than actual occurrence. MOZ indicates that the intensity and the extent of malaria potential transmission significan tly change under the climate change scenarios generated by five atmosp heric general circulation models. All five simulations reveal an incre ase in seasonal malaria at the expense of perennial malaria. This is c ause for great concern. Indeed, seasonal malaria is most likely to lea d to epidemics among unprepared or nonimmune populations. Moreover, cl imate change may trigger massive migrations of environmental refugees. Such population movements would likely put national and international health infrastructures under severe stress. Today, malaria is a devel oping country issue but could spread to higher latitudes. The results obtained with MOZ suggest that malaria could become a public-health pr oblem for developed countries within decades.