Observations on the Course of Malaria in Children in an Endemic Region

Abstract

Summary and Conclusions 1. Weekly examinations of 22 children for a period of 2 years were supplemented by dispensary examinations of the group for 3 years preceding and 1 year after the detailed examinations, plus experimental infection with the 3 species of parasites in 3 children. 2. Children are infected early in life and are reinfected at intervals. They gradually develop an immunity which enables them to tolerate later infections. In the early period, up to about 8 years of age, they may harbor parasites for long periods, but after this time they are usually able to handle reinfections with a minimum of discomfort. 3. In both relapses and reinfections the spleen enlarges briefly, but the parasite count is never so high as in primary infections. Reinfection, after eradication of the species, is relatively more severe than when the patient is a carrier. 4. Experimental infections in 3 of the children produced reinfections with a course similar to that observed in other children in the group with presumable reinfections. Reinfections are characterized by higher parasite counts and greater enlargement of the spleen than relapses. 5. Both vivax and falciparum parasites may appear in the blood stream at any time of the year, and infections may occur in the early spring.