Authors

Discussion

Schistosomiasis is a debilitating parasitic disease infecting over 240-million people and is contracted through contact with contaminated freshwater. This project focuses on Schistosoma mansoni, the main cause of intestinal schistosomiasis. The World Health Organization’s recommended control strategy is treatment with the anthelmintic praziquantel, administered by mass drug administration (MDA). However, praziquantel has possible side effects including abdominal pain, diarrhoea, dizziness and vomiting. Side effects have been reported as a reason for low treatment uptake during MDA campaigns. Epidemiological data from primary school children in a S. mansoni endemic area in Uganda,were analysed to investigate: a) whether being infected with S. mansoni, or b) infection intensity, could predict the occurrence of side effects, and c) whether side effects (except vomiting) were positively associated with successful clearance of infection after treatment and d) if vomiting was negatively associated with infection clearance post treatment. Infection intensity pre and post praziquantel treatment and side effect data were collected from three schools in Mayuge District, Uganda from 2004 to 2006. Children who vomited within an hour of treatment were retreated. Using generalized linear modelling I show that S. mansoni infection prevalence is positively associated with side effects, but the students who experienced side effects were more likely to clear infection. However, the infection intensity did not explain the number of side effects, and vomiting did not affect treatment efficacy. This research highlights that school-aged children with intestinal schistosomiasisinfection are at higher risk of experiencing side effects when given praziquantel, regardless of the intensity of infection, than uninfected children, but students who experienced side effects also had higher treatment efficacy, which indirectly supports a causal link between worm death and side effects.