Abstract:

Objective To analyze the endemic situation of schistosomiasis in Ruichang, Jiangxi Province from 2009 to 2017, so as to provide reference for formulating the corresponding prevention and control measures and strategies. Methods The annually reported data related to the prevention and control of schistosomiasis in Ruichang were collected from 2009 to 2017. These data mainly include the annual examination of schistosomiasis in the population, the treatment for the advanced schistosomiasis patients, status for livestock infection and snail control. Then a database related to the Schistosoma infections of humans, livestock and snail was established accordingly by using township as calculated units. The serological positive rate in humans, the fecal egg positive rate in livestock, the area with snail, the occurrence rate and the density of living snails were analyzed based on the database. Results A total of 736 216 individuals received examination for schistomiasis including 703 121 received serological test. Total 6 404 were serologically positive with positive rate of 0.40%~1.48%, which was statistical difference between the years (P < 0.01). The serological positive rate increased after flood in 2016 and reached to 1.45% (701/48 458) in 2017, with a significant difference compared with 2015 (0.40%, 357/90 271). Total 107 318 individuals received fecal examination with 292 egg positive, with positive rate ranging from 0 to 1.24%, with statistical difference between different years (P < 0.01). The egg positive patients were mainly distributed in 7 townships including Xiafan (25.68%, 75/292), Fanzhen (21.23%, 62/292), Matou (15.75%, 46/292), Guilin (12.33%, 36/292), Gaofeng (11.99%, 35/292), Henggang (8.90%, 26/292) and Nanyang (3.42%, 10/292). There was no acute schistosomiasis patient found in consecutive 9 years. There was no fecal positive patient since 2015. However, there were still 209 cases of advanced schistosomiasis in Ruichang region mainly distributed in the town of Xiafan (73, 34.93%), Gaofen (51, 24.40%), Fanzhen (24, 11.48%), Huangjin (22, 10.53%) and Matou (15, 7.18%). The total number of 36 460 cattle were examined from 2009 to 2017, in which 258 confirmed with infection of Schistosoma, most of them distributed in Xiafan (87, 33.72%), Gaofeng (48, 18.60%), Huangjin (62, 24.42%) and Wujiao (29, 11.24%). Total 262 infected cattle received anthelmintic treatment and the mass administration of anthelmintic expanded to 29 750 cattle. The area with snails decreased year by year since 2009 (615.99 hm²), and reached to the lowest level of 584.11 hm² in 2015, however, the difference in area with snail between 2015 and 2009 was no significant. The incidence of frames with snails decreased from 20.56% in 2009 to 10.78% in 2015, with statistical differences between the years (P < 0.01). Similarly, the density of snail decreased from 0.34/frame in 2009 to 0.16 /frame in 2015, with statistical difference between the two years (P < 0.05). Affected by the flood in 2016, the area with snail increased 43.60% (838.76 hm²) compared to that in 2015 with significant difference (P < 0.01), however, there was no significant change for the occurrence rate with snail in frames and the density of snail. In 2017, the incidence of frames with snails reached to 27.94%, and the density of snails reached to 0.56/frame, which were significantly higher than that in 2015 (10.78%, 0.16/frame)(P < 0.01). This increase happened in main nine towns of Ruichang. The correlation coefficient between serological positive rate in people, fecal egg positive rates in human and cattle and the area with snail, snail density, percentage of frames with snail was low (r = -0.199-0.202), without significance. Conclusion The endemic situation of schistosomiasis in Ruichang region was decreasing year by year since 2009. However, Matou, Gaofeng, Fanzhen, Xiafan, Henggang and Guilin are still the main areas with high risk of schistosomiasis transmission and the major areas for the disease control. Snail control is difficult to be consolidated and greatly affected by flood and other natural factors. Therefore, it is critical to establish emergent plan and the monitoring system after flood to prevent rebound of schistosomiasis in the flooded area.

Key words: Schistosomiasis, Endemic status analysis, Jiangxi Province, Ruichang