Sustaining Control of Schistosomiasis Mansoni in Western Côte d’Ivoire: Results from a SCORE Study, One Year after Initial Praziquantel Administration

Abstract

BackgroundThe Schistosomiasis Consortium for Operational Research and Evaluation (SCORE) has launched several large-scale trials to determine the best strategies for gaining and sustaining control of schistosomiasis and transitioning toward elimination. In Côte d’Ivoire, a 5-year cluster-randomized trial is being implemented in 75 schools to sustain the control of schistosomiasis mansoni. We report Schistosoma mansoni infection levels in children one year after the initial school-based treatment (SBT) with praziquantel and compare with baseline results to determine the effect of the intervention.MethodologyThe baseline cross-sectional survey was conducted in late 2011/early 2012 and the first follow-up in May 2013. Three consecutive stool samples were collected from 9- to 12-year-old children in 75 schools at baseline and 50 schools at follow-up. Stool samples were subjected to duplicate Kato-Katz thick smears. Directly observed treatment (DOT) coverage of the SBT was assessed and the prevalence and intensity of S. mansoni infection compared between baseline and follow-up.Principal FindingsThe S. mansoni prevalence in the 75 schools surveyed at baseline was 22.1% (95% confidence interval (CI): 19.5–24.4%). The DOT coverage was 84.2%. In the 50 schools surveyed at baseline and one year after treatment, the overall prevalence of S. mansoni infection decreased significantly from 19.7% (95% CI: 18.5–20.8%) to 12.8% (95% CI: 11.9–13.8%), while the arithmetic mean S. mansoni eggs per gram of stool (EPG) among infected children slightly increased from 92.2 EPG (95% CI: 79.2–105.3 EPG) to 109.3 EPG (95% CI: 82.7–135.9 EPG). In two of the 50 schools, the prevalence increased significantly, despite a DOT coverage of >75%.Conclusions/SignificanceOne year after the initial SBT, the S. mansoni prevalence had decreased. Despite this positive trend, an increase was observed in some schools. Moreover, the infection intensity among S. mansoni-infected children was slightly higher at the 1-year follow-up compared to the baseline situation. Our results emphasize the heterogeneity of transmission dynamics and provide a benchmark for the future yearly follow-up surveys of this multi-year SCORE intervention study.

Schistosomiasis Sustained Control Program in Ethnic Groups Around Ninefescha (Eastern Senegal)

“…24,25 An increase of S. mansoni prevalence was also observed in Senegal 10 months after praziquantel administration, in Mali after four rounds of praziquantel treatment, and in Ivory Coast 1 year after MDA. [26][27][28] Since the beginning of 2015, we have been carrying out an observation program that monitors the schistosomiasis prevalence in one-third of children 6-14 years of age, whether they attend school or not, but only in the villages that had positive cases in 2014. As for PSAC, prevalence is still monitored in all the children less than 6 years of age in Assoni and only children positive for schistosomiasis are treated.…”

Schistosomiasis as a disease of stem cells

“…To put the scope of this problem into perspective, some estimates suggest that the global morbidity due to schistosome infection may reach levels rivaling diseases including malaria, TB, and perhaps even HIV/AIDS [4]. Further, treatment of schistosomiasis relies upon a single drug (praziquantel) and it remains unclear how effective this drug will be in eradicating this disease in the developing world [5]. …”

Tegumental changes induced in adult S. mansoni by limonin: animal experimental and electron microscopic studies

“…The majority (up to 90 %) of the cases are located mainly in sub-Saharan Africa [1,2] . Praziquantel is the major chemotherapeutic agent for treatment of schistosomiasis as well as other helminthesiasis [3][4][5] . In view of the growing resistance to this therapy, attempts are made to explore other new anti-schistosomal options [6] .…”