IGG4 RESPONSES TO ANTIGENS OF ADULT NECATOR-AMERICANUS - POTENTIAL FOR USE IN LARGE-SCALE EPIDEMIOLOGIC STUDIES

Described is an epidemiological investigation of hookworm infections i n a rural community in Zimbabwe, where Necator americanus is the only human helminth species present. Among a cohort of 120 individuals the overall prevalence of infection was 78%. Intensity of infection was qu antified both as egg counts (range: 0-2563 eggs per g of stool) and wo rm burden (range: 0-100 worms). Although both these measures provide u seful quantitative data, they are tedious to determine in large-scale epidemiological studies and may present social and logistic difficulti es. As an alternative screening method, we therefore investigated isot ype-specific responses to adult worm antigens of N. americanus. The re sults show that specific IgG4 responses correlate positively and signi ficantly with both measures of intensify and may be a useful marker of hookworm infection.