EFFICIENT ASSESSMENT OF FILARIASIS ENDEMICITY BY SCREENING FOR FILARIAL ANTIGENEMIA IN A SENTINEL POPULATION

We have previously reported that a monoclonal antibody-based antigen d etection assay (AD12) is sensitive and specific for Bancroftian filari asis in Egypt. The purpose of the present study was to demonstrate the use of this assay in a sentinel population as a means of efficiently screening for filariasis endemicity. Antigen testing was performed wit h finger-prick blood collected during the day from 743 schoolchildren (ages 11-16 years). The school draws students from 5 villages in Qalub ia Governorate, 35 km north-east of Cairo, Egypt. The prevalence of fi larial antigenaemia in the school was 17.2%. Antigenaemia rates in chi ldren from the 5 villages were 29, 20, 18, 17, and 10% (non-uniformity significant by chi(2) analysis, P = 0.02), These data agree with Mini stry of Health rankings of relative endemicity for these villages base d on prior night blood surveys. The village with the highest antigen p revalence in children was surveyed one year before the present study. Prevalence rates of antigenaemia and microfilaraemia at that time for a different sample of children aged 11-16 years were 33% and 22%, resp ectively. We conclude that antigen detection in schoolchildren of this age group is an efficient means of assessing filariasis endemicity in Egypt.