Surveillance of schistosomiasis in People's Republic of China in 2015

Abstract

To analyze the investigation data of the national schistosomiasis surveillance sites in 2015, so as to provide scientific evidences for schistosomiasis control, elimination and surveillance. According to National Schistosomiasis Surveillance Programme (version 2014), 457 surveillance sites were selected, and the investigation data in residents, floating population, domestic animals and Oncomelania hupensis snails were collected and analyzed from four types of endemic counties. A total of 4 468 seropositive cases were detected from 133 350 residents, among which 4 457 residents with seropositive results received the etiological tests, and 71 of them were identified with positive results. Most of them were fishermen and farmers in the middle and old-aged group. The schistosomiasis infection rate was 0.05% in local population. Totally 977 seropositive cases were examined from 85 047 migrant individuals, and 16 positive cases were found out from 966 individuals who took etiological tests, which showed the schistosomiasis infection rate was 0.02% in floating population. Imported cases were found among floating people in four provinces, namely Zhejiang, Hunan, Hubei and Anhui provinces. No acute schistosomiasis cases were reported. A total of 13 406 head of cattle received examinations and only 5 were determined as stool positives. The cattle infection rate was 0.04%. The snail survey covered an area of 22 295.13 hm2 and snails were found in an area of 7 426.63 hm2, including 3.47 hm2 newly detected area with snails. No schistosome-infected snails were found. Based on the collected data from 457 national schistosomiasis surveillance sites of China, the Schistosoma japonicum infection rate is 0.05% in local population which maintains a stably descending trend. In floating population, there are imported schistosome-in-fected persons. Cattle are still a vulnerable species infected with schistosome. Although no infected snails are found, snails are widely distributed in endemic areas. Some provinces detect areas with snails for the first time or the reproduction of snails. The staff in endemic provinces should carry out the surveillance work according to National Schistosomiasis Surveillance Programme (version 2014) to improve the surveillance system, and enhance the sensibility and effectiveness of surveillance work.