Abstract:

Objective  To understand the infectiion status of schistosome in water body of risk areas in order to early release the warnings and implement comprehensive measures to prevent the prevalence of acute schistosomiasis. Methods  The data were collected on the endemic status of schistosomiasis in Dantu District of Zhenjiang City from 2006 to 2008, and 6 surveillance sites were determined at the focal waters distributed in the towns of Dantu area. Surveillance was performed over the snail infestation, water infectivity, prevalence of miracidia of Schistosoma japonicum in the focal water body from May to September between 2009 and 2010, and the positive were released in timely manner. Emergency measures were implemented, including intensive monitoring over the water infectivity, investigation on the status of snail infestation and its eradication as well as health education. Results  Infested snails were free during the period of surveillance. A total of 1200 sentinel mouse were distributed, and 1126 were recovered(93.83%), in which 13 were found positive(1.15%). Three sites were potentially infested, and one site was suspected in consecutive 2 surveillances in June and July of 2010. 5 500 sentinel snails in 6 000 were recovered(91.67%), in which 3 311 received detection by the cercaria-shedding test, and showed no infections. Four times of warnings were released on the positive results. Screening examination of the 1 482 subjects contacted with the infested water by dipstick dye immunoassay (DDIA), positive results were found in 82(5.53%), and 7 were positive stools(0.47%). Seven in 169 herds of sheep were detected with infection(4.14%). A total of 15hm2 of water body within the monitoring sites were surveyed, where showed no snail infestation. Eradication of the snails and miracidia was performed respectively in 20hm2 and 11hm2 of water body. No single case of acute schistosomiasis occurred in two-year period of surveillance. Conclusion  Surveillance over the water body of risk areas may effectively control the incidence of schistosomiasis endemic through early warning and emergency management.

Key words: Schistosomiasis, Surveillance, Forecast, Emergency management