Association between parasite-reactive antibody production and host age (A) and schistosomiasis treatment (B).

<p>Demographic and social information were obtained from the questionnaire, and antibody levels were estimated by ELISA. There was an inverse correlation between host age and IgG anti-SEA levels, as shown by Spearman analysis (A). The concentration of parasite-specific IgE was significantly lower (Mann-Whitney test) in individuals that had received previous Schistosoma treatment and were re-infected (B). Antibody levels showed no association with other demographic and social factors evaluated.