Effectiveness of Semestrial Mass Administration of Praziquantel 600 mg in the Schistosomiasis High Transmission Areas of Senegal River Basin

Introduction: Urinary and intestinal Schistosomiasis remains a major cause of morbidity and mortality in various countries, especially in Subsaharan Africa. However, the importance of periodic administration of Praziquantel 600 mg has been confirmed by the WHO. In the Senegal River Delta, intensity and transmission rates remain high despite several yearly mass treatment campaigns.

Place and Duration of Study: This study was carried out in Richard Toll (Saint-Lois, Senegal) from February 2013 to November 2015.

Aim: The objective of this study was to determine the Effectiveness of semestrial mass administration of Praziquantel 600 mg in the Schistosomiasis high transmission areas of Senegal River Basin.

Methods: Four villages were randomly divided into two groups (control and study group) comprised of two villages each. The study population consisted of children of school age (5 to 14 year old) identified in the selected villages. A first mass administration operation was carried out in the 4 villages in order to ensure an identical starting point in the entire study population. Six (06) months later, a first baseline survey provided the prevalence of Schistosomiasis in the 4 villages. It was followed by a second mass administration operation in the study group only. A second survey was performed after six months to compare the effects of bi annual mass administration with that of an annual mass administration.

Results: In respect to Schistosoma haematobium, prevalence was statistically lower after intervention: 10.8% versus 35% (p <10-3). The same effect was noted for Schistosoma mansoni: 7.9% versus 23.8% (p = <10-3). The prevalence of Schistosoma heamatobium at 6 months after the second drug administration was 0.0% while that of Schistosoma mansoni was 5.8%. In the control villages, the prevalence rate was still high after the mass administration campaign: 36.6% versus 21.7% (p = 0.011) for Schistosoma heamatobium and 15% versus 10% (p = 0.242) for Schistosoma mansoni. Our results show that a biannual administration of this molecule reduced by 100% the prevalence of S. haematobium and by more than 75% that of S. mansoni.

Conclusion: This research suggests that, in order to eliminate schistosomiasis in high transmission areas of the Senegal River Basin, praziquantel 600 mg mass administration could be renewed every 6 months.