A Controlled Study of Morbidity of Schistosomiasis Mansoni in St. Lucian Children, Based on Quantitative Egg Excretion (original) (raw)

A study of the morbidity of schistosomiasis mansoni was made in 138 school-children (age range, 7–16 years) in St. Lucia. The study was based on quantitative egg excretion data collected over a 4-year period before the study and included a comparable uninfected control group. All examinations were carried out “blind.” Infected subjects were divided into three levels of intensity of infection: heavy, 400 or more eggs/ml of feces; moderate, 100 to 300 eggs/ml; and light, 10 to 75 eggs/ml. The children were hospitalized for medical histories and physical and laboratory examinations. Gastrointestinal symptoms were present at relatively high levels in all groups, and were no more frequent in the _Schistosoma mansoni_-infected subjects than in the controls. Anthropometric measurements showed no differences among the groups. Hepatomegaly and splenomegaly were significantly more frequent in the heavy-moderate infection group, and extension of the liver below the costal margin was found to increase with intensity of infection. Serum globulin level and skin-test reactivity were directly related to intensity of infection; serum albumin level was inversely related. It was clear that in this St. Lucian study, infection with S. mansoni did not result in disease in most of the school-age subjects investigated; assessment of possible long-term (>4 years) effects was not made. This study provides a method for assessing morbidity of schistosomiasis based on quantitative egg excretion and demonstrates the relation of objective morbidity to intensity of infection.

Author Notes

*Staff member, The Rockefeller Foundation.

†External staff, British Medical Research Council; seconded to The Rockefeller Foundation.