文章基本信息

标题：Schistosomiasis is more prevalent than previously thought: what does it mean for public health goals, policies, strategies, guidelines and intervention programs?
本地全文：下载
作者：Daniel G. Colley ; Tamara S. Andros ; Carl H. Campbell 等
期刊名称：Infectious Diseases of Poverty
印刷版ISSN：2049-9957
出版年度：2017
卷号：6
期号：1
页码：63
DOI：10.1186/s40249-017-0275-5
语种：English
出版社：BioMed Central
摘要：Mapping and diagnosis of infections by the three major schistosome species (Schistosoma haematobium, S. mansoni and S. japonicum) has been done with assays that are known to be specific but increasingly insensitive as prevalence declines or in areas with already low prevalence of infection. This becomes a true challenge to achieving the goal of elimination of schistosomiasis because the multiplicative portion of the life-cycle of schistosomes, in the snail vector, favors continued transmission as long as even a few people maintain low numbers of worms that pass eggs in their excreta. New mapping tools based on detection of worm antigens (circulating cathodic antigen – CCA; circulating anodic antigen – CAA) in urine of those infected are highly sensitive and the CAA assay is reported to be highly specific. Using these tools in areas of low prevalence of all three of these species of schistosomes has demonstrated that more people harbor adult worms than are regularly excreting eggs at a level detectable by the usual stool assay (Kato-Katz) or by urine filtration. In very low prevalence areas this is sometimes 6- to10-fold more. Faced with what appears to be a sizable population of “egg-negative/worm-positive schistosomiasis” especially in areas of very low prevalence, national NTD programs are confounded about what guidelines and strategies they should enact if they are to proceed toward a goal of elimination. There is a critical need for continued evaluation of the assays involved and to understand the contribution of this “egg-negative/worm-positive schistosomiasis” condition to both individual morbidity and community transmission. There is also a critical need for new guidelines based on the use of these more sensitive assays for those national NTD programs that wish to move forward to strategies designed for elimination.
关键词：Schistosomiasis mansoni ; Circulating cathodic antigen ; Kato-Katz ; Mapping ; Diagnosis