National Control Program of Communicable Diseases, Ministry of Health of Benin, Cotonou, Benin.
Department of Zoology, Faculty of Sciences and Techniques, University of Abomey-Calavi, Cotonou, Benin.
PLoS Negl Trop Dis. 2018 Mar 1;12(3):e0006241. doi: 10.1371/journal.pntd.0006241. eCollection 2018 Mar.
National mapping of soil-transmitted helminth infections (STH) was conducted for the first time in all of the 77 districts of Benin (West Africa) from 2013 to 2015. This mapping aimed to provide basic epidemiological data essential for the implementation of the national strategy against the neglected tropical diseases (NTDs) in the context of achieving the WHO target of controlling these infections by 2020.
In each district, 5 schools were purposively selected in 5 villages and 50 school-children (25 girls and 25 boys) from ages 8 to 14 years were randomly enrolled in each school. In total, 19,250 stool samples of school children (9,625 girls and 9,625 boys) from 385 schools were examined by Kato-Katz technique.
The three major species of STH (hookworm, Ascaris lumbricoides and Trichuris trichiura) were observed with intra- and inter-specific variations in the prevalence and the intensity of these parasites. Hookworm infection was present in all of the surveyed districts with an average prevalence of 17.14% (95% CI 16.6%-17.6%). Among the infected schoolchildren, at national level, 90.82%, 6.73% and 2.45% of infections were of light, moderate and heavy parasite intensities respectively. A. lumbricoides infection, with a national average prevalence of 5.35% (95% CI 5.00%-5.60%),was the second most prevalent STH, and 84.37%, 14.27% and 1.36% of the infections were of light, moderate and heavy parasite intensities, respectively. T. trichiura had a national average prevalence of 1.15% (95% CI 0.90%-1.20%) and 80.45%, 13.18% and 6.36% infections were of light, moderate and heavy parasite intensities, respectively. The national cumulative prevalence of the three STH infections was 22.74% (95% CI 22.15%-23.33%), with58.44% (45/77) of the districts requiring mass treatment according to WHO recommendations. In all of the surveyed districts, multiple infections by STH species were common, and boys seemed more at risk of hookworm and Ascaris infections.
This first national mapping provided an overview of the epidemiological pattern of STH infections and was essential for the implementation of a control strategy with an effective preventive chemotherapy treatment (PCT). Results show that while preventive chemotherapy is not indicated for children in 32/77 districts, 43 require annual deworming and two require twice yearly deworming. If no environmental change occurs, and no mass treatment is delivered, prevalence is likely to remain stable for many years owing to poor hygiene and sanitation.
2013 年至 2015 年，贝宁（西非）77 个区首次进行了全国土壤传播性蠕虫感染（STH）绘图。这一绘图旨在提供基本的流行病学数据，这对在实现世卫组织到 2020 年控制这些感染的目标的背景下实施针对被忽视的热带病（NTDs）的国家战略至关重要。
在每个区，5 所学校被有目的地选择在 5 个村庄中，并且每个学校随机招募 50 名 8 至 14 岁的学童（25 名女孩和 25 名男孩）。总共有来自 385 所学校的 19250 名学童（9625 名女孩和 9625 名男孩）的粪便样本接受了加藤厚涂片检查。
观察到三种主要的 STH（钩虫、蛔虫和鞭虫），其流行率和寄生虫强度存在种内和种间差异。在所有调查的区都存在钩虫感染，平均流行率为 17.14%（95%CI 16.6%-17.6%）。在全国范围内，感染的学龄儿童中，90.82%、6.73%和 2.45%的感染分别为轻度、中度和重度寄生虫强度。蛔虫感染的平均流行率为 5.35%（95%CI 5.00%-5.60%），是第二大常见的 STH，84.37%、14.27%和 1.36%的感染分别为轻度、中度和重度寄生虫强度。鞭虫的平均流行率为 1.15%（95%CI 0.90%-1.20%），80.45%、13.18%和 6.36%的感染分别为轻度、中度和重度寄生虫强度。三种 STH 感染的全国累积流行率为 22.74%（95%CI 22.15%-23.33%），根据世卫组织的建议，58.44%（45/77）的区需要进行大规模治疗。在所有调查的区，多种 STH 物种的混合感染很常见，而且男孩似乎更容易感染钩虫和蛔虫。
这是第一次全国性的绘图，提供了 STH 感染的流行病学模式概述，这对于实施有效的预防性化疗治疗（PCT）控制战略至关重要。结果表明，虽然 32/77 个区的儿童不需要预防性化疗，但 43 个区需要每年驱虫，两个区需要每两年驱虫一次。如果环境没有变化，并且没有进行大规模治疗，由于卫生和环境卫生条件差，流行率可能在多年内保持稳定。
