The Impact of Anthelmintic Treatment on the Incidence of Diarrheal Disease in Vietnamese School Children

Cheap and effective drugs called 'anthelmintics' are routinely administered to children in developing countries to eliminate infections by parasitic helminths. However, the effects of anthelmintic treatment on other pathogens (e.g., bacteria, viruses, protozoa) remain unknown. The aim of this study is to investigate the impact of anthelmintic treatment on the incidence of viral- and bacterial-induced diarrhea in school children in southern Vietnam. Diarrheal disease remains a substantial cause of morbidity and mortality in children in Vietnam, and these children are typically co-infected with intestinal helminths. As helminths and diarrheal pathogens infect the same intestinal niche, anthelmintic treatments may alter host immune responses and the composition of the gut microbiota in ways that affect infection and disease risks caused by diarrheal pathogens. This study will recruit 350 helminth-infected and 350 helminth-uninfected children aged 6-15 years. Recruited children will be randomized to receive either anthelmintic or placebo treatment once every three months and will be monitored for incidences of diarrheal disease for 12 months. At the 12-month time point, all children will receive anthelmintic treatment. Blood and stool samples will be collected throughout the study and used for evaluation of anemia and host immune responses, and for classification of gut microbes and parasite detection, respectively. The interventional study proposed here will provide an important first test of whether anthelmintic treatments have any indirect effects on infections caused by diarrheal pathogens.