Background Annual school-based mass treatment with praziquantel is the cornerstone for schistosomiasis control among school-age children in Uganda. However, uptake of treatment is low. We evaluated strategies for improved uptake of mass treatment and the effects on the prevalence and mean intensity of S. mansoni infection

Methods Through serial cross-sectional surveys conducted in 2011 and 2012 in 12 primary schools in Jinja district and a cluster randomised trial conducted in 2013, the levels of uptake of praziquantel and the prevalence and mean intensity of S. mansoni infection among school children were determined. Additionally, in 2012, the effect of increased teacher motivation to distribute treatment was assessed. In 2013, the effectiveness of provision of a pre-treatment snack in improving uptake was evaluated.

Results A total of 1010, 1020 and 1284 randomly selected children were enrolled in 2011, 2012 and 2013, respectively. Uptake of praziquantel was 28.2% (95% CI: 22.9%–33.6%) in 2011. Prevalence and intensity of S. mansoni infection was 35.0% (95% CI: 25.4%–37.9%) and 116.1 eggs per gram of stool (epg) (95% CI 98.3–137.1), respectively. With increased teacher motivation in 2012, uptake increased to 48.9% (95% CI: 45.8%–52.0%). The prevalence and intensity of S. mansoni infection was 32.6% (95% CI: 29.6%–35.5%) and 133.1 epg (95% CI: 99.0%–167.2%), respectively. Provision of a pre-treatment snack in 2013 increased uptake to 85.5% (95% CI: 82.5%–91.7%) and reduced the prevalence and intensity of S. mansoni infection to 8.2% (5.6%–12.2%) and 15.9 epg (95% CI: 12.3%–19.2%), respectively.

Conclusions Although teacher motivation increased uptake of mass treatment, the realised uptake was too low to affect the prevalence and intensity of schistosomiasis among school children. Conversely, provision of a pre-treatment snack achieved a high uptake. The increased uptake significantly reduced the prevalence and intensity of S. mansoni infection in this age group.