Relationships between malaria prevalence and malaria-related morbidity in school children from two villages in central Africa

To investigate the relationship between parasite prevalence and malaria-rel ated morbidity, we carried out a comparative study among cohorts of school children from two villages, Dienga, Gabon, and Pouma, Cameroon, both locate d in malaria-endemic areas. Seven to 17 year-old children attending primary schools were similarly followed-up at each site to evaluate the frequency of malaria attacks. Follow-up involved daily temperature recording (and blo od smears in the case of fever) and preparation of blood smears every two w eeks. In Pouma, 186 children were followed-up for six months. In Dienga, 22 8 children were followed-up for nine months. The mean prevalence rate of Pl asmodium falciparum infections (as assessed by the blood smears) was twice as high in Pouma compared with Dienga (45.2% versus 26.8%; P < 0.0001), whe reas the monthly malaria attack rate (as assessed by the daily surveillance ) was twice as high in Dienga compared with Pouma (21.5% versus 41.4%; P = 0.003). The possible implication of several parameters that may differ betw een the two areas, such as the malaria transmission level, the economical a nd social status of the inhabitants, the characteristics of infecting paras ite strains, and the genetic background of the population, is discussed.