What has caused Malaria epidemics to end in past occurences?
• The epidemic grows in a series of steps representative of the incubation interval (the period between the occurrence of infective gametocytes in the primary case and their reappearance in a secondary case), which is about 20 days for P.vivax and 35 days for P.falciparum. The length of the incubation interval and the degree of the reproduction rate determine the rate of multiplication of transmission, which is much faster in P.vivax epidemics than in those due to P.falciparum. In areas where both P.vivax and P.falciparum are present, the initial stages of an epidemic will thus be determined by a predominance of P.vivax infections and a very gradual increase in severity of the epidemic, while in later stages P.falciparum is likely to be abundant. • The peak of new infections due to a P.falciparum epidemic will only be reached when roughly 50 percent of the population at risk is infected, unless climatic changes (notably colder temperatures) prevent further transmission. Control of a ma
