Surveillance of schistosomiasis 34 years after transmission interruption in Songjiang District, Shanghai City / 中国血吸虫病防治杂志

ABSTRACT

Objective To analyze the surveillance data after schistosomiasis transmission interruption from 1985 to 2018, so as to provide scientific basis for the future prevention and control of schistosomiasis. Methods The data pertaining to snail survey, surveillance of schistosomiasis in humans and livestock, and health education were collected and analyzed in Songjiang District after schistosomiasis transmission interruption from 1985 to 2018. Results From 1985 to 2018, there were 8 townships, 68 villages and 1 462 settings with snails in Songjiang District, covering an area of 96.399 hm2. There were 4 townships and 59 villages with snails newly identified in previously schistosomiasis non-endemic areas, with emerging snail habitats of 60.161 hm2. A total of 26 148 snails were captured, and no infections were detected. The snail habitats were mainly distributed in the river course, ditches and farmlands, which accounted for 45.28%, 33.17% and 21.55% of total snail habitats, respectively. A total of 245 955 humans were subjected to the serological test, with a positive rate of 0.03%, and 37 humans were subjected to the parasitological test, with 3 positives detected. These three egg-positives were all imported chronic cases with schistosomiasis. A total of 9 109 livestock were detected using the serological test, and no infection was found. Most of the awareness rate of schistosomiasis control knowledge and the rate of correct behavior formation were over 80% in residents and students. Conclusions The achievements of schistosomiasis control are consolidated in Songjiang District; however, there are still risk factors of schistosomiasis transmission, including residual snails, snail diffusion and importation of external source of infection. The future surveillance of schistosomiasis should focus on snails and sources of infection.