Kloos H, Higashi G, Schinski V D, Mansour N S, Murrell K D, Miller F D
United States Medical Research Unit Number 3, Cairo, Egypt.
Int J Epidemiol. 1990 Sep;19(3):749-58. doi: 10.1093/ije/19.3.749.
The quantitative relationship between water contact and Schistosoma haematobium infection was studied in a cohort of male school children aged 6-17 in El Ayaisha village, Upper Egypt, during a two-year study. An exposure index (total body minutes, TBM) was used to identify the activities responsible for exposure to cercariae-infested water and to examine the relationship between water contact and infection. Results show that 65% of all contacts and 86% of all TBM were due to swimming in the Nile and canals and that swimming was the most important exposure and contamination activity. Using multivariate analysis, several sites, study periods, residence groups and mostly canal contacts were significantly correlated with egg-counts. Positive relationships could also be identified using egg-counts with water contact data from preceding study periods, indicating the influence of pre-existing infections, prepatency and seasonality of water contact and transmission. TBM were usually more significantly correlated with egg-counts than frequency and duration of contact. The relevance of the findings for control programmes and the use of school children and the exposure index for water contact studies are discussed.
在一项为期两年的研究中，对埃及上埃及省艾亚伊沙村6至17岁的男学生队列进行了研究，以探讨水接触与埃及血吸虫感染之间的定量关系。使用暴露指数（全身分钟数，TBM）来确定导致接触受尾蚴污染水的活动，并研究水接触与感染之间的关系。结果显示，所有接触的65%和所有TBM的86%是由于在尼罗河和运河中游泳，游泳是最重要的暴露和污染活动。通过多变量分析，几个地点、研究时间段、居住群体以及大多数运河接触情况与虫卵计数显著相关。利用虫卵计数与先前研究时间段的水接触数据，也能确定正相关关系，这表明既往感染、潜伏期以及水接触和传播的季节性的影响。TBM通常比接触频率和持续时间与虫卵计数的相关性更强。讨论了这些研究结果对控制项目的相关性以及在水接触研究中使用学童和暴露指数的情况。
