Relationship between malarial parasitaemia and symptoms of the disease: a review of the literature.

The relationship between parasitaemia and the clinical manifestations of malaria is a highly complex subject, considered by the WHO Expert Committee on Malaria which met in September 1958 to warrant further investigation since it has an important bearing on the organization of eradication programmes. As a first step, the author has reviewed the existing literature on such aspects of malaria epidemiology as the prevalence of gametocytes at various stages of a malarial infection, the limit of infectiousness of the human host, the period of survival of the malaria parasite in man, and the development of immunity through repeated infection. From this study of the works published during the past 60 years, he concludes that much more information as to the role of asymptomatic parasitaemia in the transmission of malaria is required and suggests that it will best be obtained through a critical analysis of the data recorded during the eradication campaigns now under way in many countries.