Serological malaria surveys in Nigeria.

A parasitological and serological malaria survey of 2 large and 2 small areas of Nigeria was carried out in connexion with the activities of the WHO Treponematoses Epidemiological Team.The results, based on data obtained from 1082 subjects, showed that all the areas were holoendemic with the usual pattern of malariometric indices, and that the differences between the parasite rates of the two large areas were due to the different timing of the survey in relation to the seasonal wave of transmission.The fluorescent antibody test was positive (>/=1:20) in 92% of the 914 sera collected from these 2 areas.The serological profile of the population in the 2 areas was similar, but the immunofluorescence titres were higher in all age-groups in the area south of the Benue river, indicating the antibody response to the previous endemic wave rather than the actual amount of transmission taking place at the time of the survey.This study confirms the value of the immunofluorescent technique for large-scale malaria surveys, but indicates the need for caution in interpreting the results and stresses the importance of good knowledge of the local epidemiology of malaria before embarking on application of serological methods.