Abstract:

Objective　To analyze the changes of endemic situation of schistosomiasis in the national surveillance sites of Yueyang City from 2016 to 2020,so as to supply scientific evidences in improving the prevention and control measures as well as developing the strategies for schistosomiasis elimination in Yueyang City.Methods　According to the requirements of the National Schistosomiasis Monitoring Scheme(2014 Edition),we established 12 national schistosomiasis monitoring sites within Yueyang areas for systematic surveillance of schistosomiasis infections in local residents,floating population and livestock as well as the status of snail.Results　Totally,28 980 local residents-times and 12 316 floating people-times in the 12 national surveillance sites in Yueyang area underwent serological screening for Schistosoma japonicum infection from 2016 to 2020. The positive rate of blood test was 3.62%,3. 36%,2. 43%,1. 64% and 0. 97% for local residents,and 3. 60%,1. 90%,1. 41%,0. 96% and 0. 49% for floatingm population,respectively in each year,which showed a declined trend year by year. Fecal tests carried out in 2016 revealed positive infection with Schistosoma japonicum in 12 of the local residents and only 1 in floating population. A total of 2 598 livestock-times were monitored in the 5 years,and no infectious animals were found. In addition,snail survey was implemented in an area of 7 441. 09 hm2,which showed that the average density of live snails was dropped to the lowest level in 2019,and no infected snails were detected. A total of 554 mixed snail samples were detected using loop-mediated isothermal amplification(LAMP),only 3 positive mixed samples were identified in 2017.Conclusion　Overall,schistosomiasis prevalence tends to decline in Yueyang City,yet areas with snails remains larger,and the risk of schistosomiasis transmission still exists. In following efforts,we should continue to strengthen comprehensive prevention and control measures,including expanded screening of schistosomiasis,provision of health education in population,enhanced snail control,and perfecting the monitoring system,in order to promote the process in eliminating schistosomiasis.

Key words: Schistosomiasis, Endemic situation, Surveillance, Yueyang City