[Endemic status of schistosomiasis in People's Republic of China in 2016].

Abstract

This report presents the endemic status of schistosomiasis in the People's Republic of China at national level in 2016, and analyzes the data collected from the national schistosomiasis prevention and control system and 454 national schistosomiasis surveillance sites. Among the 12 provinces (municipality and autonomous region) of endemic of schistosomiasis japonica in P. R. China, 5 provinces (municipality and autonomous region), i.e., Shanghai, Zhejiang, Fujian, Guangdong and Guangxi, had achieved elimination, and 7 provinces of Sichuan, Yunnan, Jiangsu, Hubei, Anhui, Jiangxi and Hunan had achieved transmission control by the end of 2016. There are 451 endemic counties (cities, districts) covering 257 million people, specifically including 29 692 endemic villages of 69.39 million people at risk. Among the 451 endemic counties (cities, districts), 35.25 % (159/451), 42.35% (191/451) and 22.39% (101/451) reached the criteria of elimination, transmission interruption and transmission control, respectively in 2016. By the end of 2016, it was estimated of 54 454 infections of schistosome, decreased by 29.46% compared with 77 194 in 2015. No acute schistosomiasis case was reported in 2016. There were 30 573 advanced schistosomiasis cases documented in 2016. A total of 8 500 710 individuals received schistosomiasis examinations and 600 individuals were parasitologically diagnosed, decreased by 83.36% compared with 3 606 in 2015. The Oncomelania hupensis snail survey was performed in 22 140 endemic villages and O. hupensis snails were found in 7 106 villages, accounting for 32.109% of the total villages, with 20 newly detected villages with snails. The snail survey covered area of 813 963.91 hm2 and snails were found in an area of 235 096.04 hm2, including a newly detected area of 1 346.48 hm2. No schistosome-infected snails were found in 2016. A total of 881 050 bovines were raised in the schistosomiasis endemic area. Of them, 510 468 bovines received examinations, resulting in 8 schistosome-infected bovines. There were 147 642 schistosomiasis cases receiving drug treatment in 2016, with 2 303 555 individuals undergoing expanded chemotherapy; there were 9 bovines with schistosomiasis receiving drug treatment, with 439 857 bovines undergoing expanded chemotherapy; a total of 139 483.84 hm2 area with snail control by using molluscicides, with actual molluscicide-treated area of 73 941.75 hm2; and 3 101.52 hm2 snail habitants were treated by environmental modification. Based on the data from the 454 national schistosomiasis surveillance sites, the mean Schistosoma japonicum infection rate was 0.02% and 0.0078% in humans and bovines, respectively. No schistosome-infected snails were found in all the surveillance sites. The results demonstrate a decline in the endemicity of schistosomiasis in P. R. China compared with the level of 2015. However, the distribution area of snails in China is still large and the infection source of schistosomiasis still exists to some extent in some endemic areas; in some regions, the task to reach the standard of transmission interruption is still arduous. There are still objective factors of epidemic and transmission and risk factors of endemic reversal and rebound for schistosomiasis. So, further control and effective surveillance as well as accurate prevention and control should be implemented to promote the elimination process on schistosomiasis in P. R. China.