Abstract

PIP: Snow et al. reported, on the basis of hospital admissions from five defined African communities exposed to very different intensities of malaria transmission, a decline in the severity of malaria from areas of low-to-moderate to areas of high transmission. They found, among children aged 0-9 years, a decline in admission rates for all-cause malaria and more so for cerebral malaria, a levelling-off or slight decline in the admission rate for severe malarial anemia, and a lowering of the mean age of all-cause malaria admissions. There are problems, however, with using the intensity of transmission as the independent variable and malaria mortality or the incidence of life-threatening malaria as the dependent variable. Nonetheless, Snow et al.'s observation does not justify withholding preventive measures from people in malaria situations. What Snow et al. have shown, however, is the need for a new synthesis of the epidemiology of malaria. Meanwhile, the choice of preventive measure should depend upon the benefits expected from the strategy and take into consideration that in areas of intense transmission, partial prevention may lead to an increased incidence of cerebral malaria.