Abstract

Two schools in rural Tanzania were surveyed regarding the pupils' nutrition (weight and height), serum immunoglobulins (IgA, IgG, IgM, and IgE), autoantibodies, malaria antibodies, hepatitis B antigenemia, and fecal and urinary parasites. The survey attempted to quantify the relative importance of undernutrition and parasitic infestation in determining the serological abnormalities found. Of all the children surveyed 69% were undernourished (less than 80% of expected weight for age); 63% had fecal parasites and 38% had urinary schistosomiasis. Serum IgG and IgM concentrations were raised and the serum IgE concentration was strikingly raised (mean 4990IU/ml). Elevated serum IgE was associated with ascariasis. Autoantibodies were common but no autoimmune disease was detected. Notably there was a 35% prevalence of reticulin antibody. This reticulin antibody positivity correlated with increased malaria antibody concentrations. Reduced malaria antibody concentration was significantly associated with hepatitis B antigenemia. The study illustrates that parasites, notably malaria, are important determinants of the serum antibodies of children in the tropics and suggests that mild undernutrition has little effect.