Evaluating the impact of biannual school-based and community-wide treatment on urogenital schistosomiasis in Niger

Parasites & Vectors

Zilahatou Tohon¹  Adamou Garba Noma¹  Bassirou Madougou¹  Amina A. Hamidou¹  Kader M. Halilou¹  Hannatou Sebangou¹  Oumarou Alto¹  Roumanatou Andia¹  Boubacar Sofo¹  Amadou Garba¹  Boubacar Sidikou²  Anna E. Phillips³  Issa Gnandou⁴  Alan Fenwick⁵  Neerav A. Dhanani⁵ 

[1] Aménagement et Lutte (RISEAL NIGER), Réseau International Schistosomiases Environnement, BP. 13724, Avenue de l’indépendance, Niamey, Niger;Hôpital National de Niamey rond-point Hôpital, BP 238, Niamey, Niger;London Centre for Neglected Tropical Disease Research (LCNTDR), Department of Infectious Disease Epidemiology, Imperial College London, London, UK;Ministère de la Santé, Niamey, Niger;Schistosomiasis control Initiative (SCI), Department of Infectious Disease Epidemiology, Imperial College London, London, UK;

关键词: Schistosomiasis;    Urogenital schistosomiasis;    Community-wide treatment;    School-based treatment;    Biannual treatment;    Elimination;   

DOI  :  10.1186/s13071-020-04411-9

来源: Springer

【 摘 要 】

BackgroundThe Schistosomiasis Consortium for Operational Research and Evaluation (SCORE) coordinated a five-year study implemented in several countries, including Niger, to provide an evidence-base for programmatic decisions regarding cost-effective approaches to preventive chemotherapy for schistosomiasis control.MethodsThis was a cluster-randomised trial investigating six possible combinations of annual or biannual community-wide treatment (CWT), school-based treatment (SBT), and holidays from mass treatment over four years. The most intense arm involved two years of annual CWT followed by 2 years of biannual CWT, while the least intensive arm involved one year of annual SBT followed by a year without treatment and two more years of annual SBT. The primary outcome of interest was prevalence and intensity of Schistosoma haematobium among 100 children aged 9–12 years sampled each year. In addition, 100 children aged 5–8 years in their first year of school and 50 adults (aged 20–55 years) were tested in the first and final fifth year of the study.ResultsIn total, data were collected from 167,500 individuals across 225 villages in nine districts within the Niger River valley, Western Niger. Overall, the prevalence of S. haematobium decreased from baseline to Year 5 across all study arms. The relative reduction of prevalence was greater in biannual compared with annual treatment across all arms; however, the only significant difference was seen in areas with a high starting prevalence. Although adults were not targeted for treatment in SBT arms, a statistically significant decrease in prevalence among adults was seen in moderate prevalence areas receiving biannual (10.7% to 4.8%) SBT (P < 0.001). Adults tested in the annual SBT group also showed a decrease in prevalence between Year 1 and Year 5 (12.2% to 11.0%), but this difference was not significant.ConclusionsThese findings are an important consideration for schistosomiasis control programmes that are considering elimination and support the idea that scaling up the frequency of treatment rounds, particularly in areas of low prevalence, will not eliminate schistosomiasis. Interestingly, the finding that prevalence decreased among adults in SBT arms suggests that transmission in the community can be reduced, even where only school children are being treated, which could have logistical and cost-saving implications for the national control programmes.Graphical Abstract

【 授权许可】

CC BY