Koella J C
Laboratoire d'Ecologie CC 237 Université P. & M. Curie, Paris.
Schweiz Med Wochenschr. 1999 Aug 10;129(31-32):1106-10.
The transmission of malaria is largely determined by two parameters: the biting rate of the mosquito vector and its mortality. In this paper, data on the interactions among these parameters are reviewed to describe possible evolutionary mechanisms underlying the parasite's life cycle. In particular, in contrast to conventional wisdom about medical entomology, the author suggests that malaria parasites are not always expected to minimise the damage they inflict on their mosquito host. Rather, when they have developed into the infectious stage, they can increase their transmission by manipulating the mosquito to bite more frequently; this, however, is associated with a higher risk of being killed by the human host. This example illustrates that parameters determining malaria transmission can only be understood by integrating ecological and evolutionary ideas into more traditional epidemiology. Such an evolutionary view of malaria and mosquitoes will eventually lead to a better understanding of the epidemiology of malaria and may help to predict the effect of malaria control.