In a cluster randomized trial, Simon Muhumuza and colleagues examine the effectiveness of a pre-treament snack given to school-aged children on the uptake of mass treatment for schistosomiasis in Uganda.
Please see later in the article for the Editors' Summary
School-based mass treatment with praziquantel is the cornerstone for schistosomiasis control in school-aged children. However, uptake of treatment among school-age children in Uganda is low in some areas. The objective of the study was to examine the effectiveness of a pre-treatment snack on uptake of mass treatment.
Methods and Findings
In a cluster randomized trial carried out in Jinja district, Uganda, 12 primary schools were randomized into two groups; one received education messages for schistosomiasis prevention for two months prior to mass treatment, while the other, in addition to the education messages, received a pre-treatment snack shortly before mass treatment. Four weeks after mass treatment, uptake of praziquantel was assessed among a random sample of 595 children in the snack schools and 689 children in the non-snack schools as the primary outcome. The occurrence of side effects and the prevalence and mean intensity of Schistosoma mansoni infection were determined as the secondary outcomes. Uptake of praziquantel was higher in the snack schools, 93.9% (95% CI 91.7%–95.7%), compared to that in the non-snack schools, 78.7% (95% CI 75.4%–81.7%) (p = 0.002). The occurrence of side effects was lower in the snack schools, 34.4% (95% CI 31.5%–39.8%), compared to that in the non-snack schools, 46.9% (95% CI 42.2%–50.7%) (p = 0.041). Prevalence and mean intensity of S. mansoni infection was lower in the snack schools, 1.3% (95% CI 0.6%–2.6%) and 38.3 eggs per gram of stool (epg) (95% CI 21.8–67.2), compared to that in the non-snack schools, 14.1% (95% CI 11.6%–16.9%) (p = 0.001) and 78.4 epg (95% CI 60.6–101.5) (p = 0.001), respectively.
Our results suggest that provision of a pre-treatment snack combined with education messages achieves a higher uptake compared to the education messages alone. The use a pre-treatment snack was associated with reduced side effects as well as decreased prevalence and intensity of S. mansoni infection.
Please see later in the article for the Editors' Summary
Globally, more than 240 million people are infected with schistosomes, a parasitic worm found in tropical and sub-tropical fresh water. Schistosomes reproduce in snails, which release free-swimming infectious parasites that burrow into the skin of people when they wash or swim in contaminated water. Once inside a person, the parasites turn into larvae and migrate to the liver, where they become juvenile worms. These mature into 10–20 mm long adult worms and take up residence in the veins draining the gut or bladder where they mate and release eggs, some of which pass into the feces and go back into water where they hatch and infect fresh snails. Most people have no symptoms when they are first infected with schistosomes but some develop a rash or itchy skin. Later symptoms include fever, chills, cough, and muscle aches. Without treatment, schistosomiasis can persist for years, eventually causing liver, gut, bladder, and spleen damage. In Africa alone, schistosomiasis kills about 280,000 people annually.
Why Was This Study Done?
Strategies for the control of schistosomiasis include the provision of clean water and adequate sanitation, and education. However, the cornerstone of control is the reduction of disease through periodic, targeted treatment with the anti-schistosomal drug praziquantel. One group that is targeted for treatment in countries affected by schistosomiasis is school-aged children. For this approach to be successful, experts recommend regular treatment of at least 75% of school-age children at risk of infection. Unfortunately, the uptake of the intervention is often low, partly because children fear praziquantel's side effects, which include diarrhea, and vomiting. The risk of developing side effects can be reduced by eating food just before taking the drug. In this cluster randomized trial (a study that compares outcomes in groups of people randomly assigned to receive different treatments), the researchers investigate whether the provision of a pre-treatment snack improves the uptake of praziquantel among school children in Jinja district of Uganda, a country that has adopted school-based mass drug administration as part of its national schistosomiasis control program. The researchers also investigated whether this intervention reduces the occurrence of side effects attributable to praziquantel, the prevalence of schistosomiasis (the proportion of the population that is infected), and the infection intensity (indicated by the density of eggs in stool).
What Did the Researchers Do and Find?
The researchers randomly assigned 12 primary schools to receive education messages for 2 months before mass treatment with praziquantel or the same education messages plus a mango juice and donut snack just before treatment. The education messages included information about the dangers of schistosome infection, the importance of preventative treatment with praziquantel, and information about taking the drug with food to avoid side effects. Four weeks after mass treatment, praziquantel uptake was assessed by self report in 595 children chosen randomly from the snack schools and 689 children from the no-snack schools. Uptake of praziquantel in the snack and no-snack schools was 93.9% and 78.7%, respectively, a significant difference in outcomes that is unlikely to be a chance event. The occurrence of self-reported side effects, the prevalence of schistosome infection, and the average intensity of infection were all significantly lower in the snack schools than in the no-snack schools.
What Do These Findings Mean?
These findings suggest that the provision of a pre-treatment snack combined with education messages improved uptake of mass treatment for schistosomiasis among school children in Uganda compared to education messages alone. The intervention also reduced the occurrence of side effects, the prevalence of infection, and the infection intensity. Because uptake and the occurrence of side effects were determined by self-report, some children may have provided socially desirable answers. That is, they may have said they took the drug when they didn't because they knew that is what the researchers wanted to hear. However, the infection prevalence and intensity findings validate the self-reported uptake. The researchers conclude that the provision of a snack to mitigate the side effects of praziquantel could have motivated the children to take the treatment. If future trials show that the intervention is cost-effective, the researchers suggest that the provision of pre-treatment food should be integrated into school-based mass treatment programs for schistosomiasis control at the national level in Uganda and in similar settings elsewhere in sub-Saharan Africa.
Please access these websites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001640.
The World Health Organization provides detailed information about schistosomiasis (in several languages)
The US Centers for Disease Control and Prevention provides information for the public and for health professionals about all aspects of schistosomiasis (in English and Spanish)
The UK National Health Service Choices website also provides information about schistosomiasis
More information about the Evaluation of Strategies for Improved Uptake of Preventive Treatment for Intestinal Schistosomiasis trial is available
The End Fund, a US not-for-profit organization that aims to tackle schistosomiasis and other neglected tropical diseases, has a personal story about dealing with schistosomiasis