London Centre for Neglected Tropical Disease Research, London W2 1PG, UK.
Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, St Mary's Campus, Imperial College London, London W2 1PG, UK.
Trans R Soc Trop Med Hyg. 2022 Dec 2;116(12):1226-1229. doi: 10.1093/trstmh/trac033.
Soil-transmitted helminths (STH) and schistosome parasites are highly aggregated within the human population. The probability distribution of worms per person is described well by the negative binomial probability distribution with aggregation parameter, k, which varies inversely with parasite clustering. The relationship between k and prevalence in defined populations subject to mass drug administration is not well understood.
We use statistical methods to estimate k using two large independent datasets for STH and schistosome infections from India and Niger, respectively, both of which demonstrate increased aggregation of parasites in a few hosts, as the prevalence of infections declines across the dataset.
A greater attention needs to be given in monitoring and evaluation programmes to find and treat the remaining aggregates of parasites.
土壤传播性蠕虫（STH）和血吸虫寄生虫在人类群体中高度聚集。描述每个人体内蠕虫数量的概率分布可以很好地用负二项式概率分布来描述，其中聚集参数 k 与寄生虫聚类成反比。在接受大规模药物治疗的特定人群中，k 与患病率之间的关系尚不清楚。
我们使用统计方法，分别使用来自印度和尼日尔的两个大型独立 STH 和血吸虫感染数据集来估计 k，这两个数据集都表明，随着感染率在整个数据集中的下降，寄生虫在少数宿主中聚集的情况增加。
在监测和评估计划中，需要更加关注发现和治疗剩余的寄生虫聚集。
