Assessment of schistosomiasis transmission risk along the Yangtze River basin after the flood disaster in 2020 / 中国血吸虫病防治杂志

ABSTRACT

Objective To evaluate the impact of the flood disaster on schistosomiasis transmission along the Yangtze River basin in 2020, so as to provide insights into schistosomiasis prevention and control in flood-affected areas. Methods The data pertaining to the endemic situation of schistosomiasis were collected from 5 provinces of Hunan, Hubei, Jiangxi, Anhui and Jiangsu from 2013 to 2019, including Schistosoma japonicum infections in humans and livestock and snail distribution, and the warning water levels and actual water status were collected in water regions locating in these 5 provinces. The cumulative numbers of S. japonicum egg-positive individuals and bovines during the period from 2013 to 2019, the area of snail habitats in 2019 and the water level on July 12, 2020 were estimated at a county level and employed as parameters for classification of schistosomiasis transmission risk. Then, the cumulative value of each risk index was calculated to assess the risk of schistosomiasis transmission risk. Results After the flood disaster along the Yangtze River basin in 2020, there were 10, 5 and 9 counties (districts) at high risk of schistosomiasis transmission in 5 provinces of Hunan, Hubei, Jiangxi, Anhui and Jiangsu based on number of egg-positive individuals, number of egg-positive bovines and snail distribution, respectively. Based on comprehensive risk indices, there were 10 (8 in Dongting Lake regions of Hunan Province and 2 in Poyang Lake regions of Jiangxi Province) and 15 counties (districts) (4 in Hubei Province, 7 in Hunan Province and 4 in Jiangxi Province) identified at grades 5 and 4 risk of schistosomiasis transmission. Conclusions Dongting Lake regions and Poyang Lake regions are the most severely flood-affected schistosomiasis-endemic foci of China in 2020, and the flood disaster may facilitate the transmission of schistosomiasis in affected areas. Therefore, schistosomiasis control requires to be intensified after the flood disaster to prevent the rebound of the disease.