Evaluation of the measures in early warning and disposal of snail environment in a forest land in Songjiang District, Shanghai / 上海预防医学

Objective To evaluate the methods in early warning of schistosomiasis and elimination of snails in an ecological public forest in Yexie Town of Songjiang District, and provide the basis for monitoring and controlling snails in forest land in the future. Methods The monitoring data of snails, schistosomiasis and snail elimination in the public forest were collected to evaluate the effect of controlling snails. Results The area with existence of snails was found to be 10.47 hm2, and it was decreased by 98.28% after three times of snail elimination.A total of 1 904 serological tests was performed (test rate of 88.76%) with the positive rate of 0.16%.Pathogenic test result was negative in 3 subjects examined.Serological samples of 11 dogs and 1 sheep were all negative for the test.None of the 1 480 live snails tested was found to be positive in infection.The awareness rate of schistosomiasis control knowledge and behavior formation in 275 students were 98.2% and 95.3%, respectively. Conclusion The snails in the public forest in Yexie Town have been effectively controlled, but there are still scattered living snails.The measures in eliminating and monitoring of snails should be continued and strengthened.

[Surveillance of schistosomiasis 34 years after transmission interruption in Songjiang District, Shanghai City].

OBJECTIVE: To analyze the surveillance data after schistosomiasis transmission interruption from 1985 to 2018, so as to provide scientific basis for the future prevention and control of schistosomiasis. METHODS: The data pertaining to snail survey, surveillance of schistosomiasis in humans and livestock, and health education were collected and analyzed in Songjiang District after schistosomiasis transmission interruption from 1985 to 2018. RESULTS: From 1985 to 2018, there were 8 townships, 68 villages and 1 462 settings with snails in Songjiang District, covering an area of 96.399 hm2. There were 4 townships and 59 villages with snails newly identified in previously schistosomiasis non-endemic areas, with emerging snail habitats of 60.161 hm2. A total of 26 148 snails were captured, and no infections were detected. The snail habitats were mainly distributed in the river course, ditches and farmlands, which accounted for 45.28%, 33.17% and 21.55% of total snail habitats, respectively. A total of 245 955 humans were subjected to the serological test, with a positive rate of 0.03%, and 37 humans were subjected to the parasitological test, with 3 positives detected. These three egg-positives were all imported chronic cases with schistosomiasis. A total of 9 109 livestock were detected using the serological test, and no infection was found. Most of the awareness rate of schistosomiasis control knowledge and the rate of correct behavior formation were over 80% in residents and students. CONCLUSIONS: The achievements of schistosomiasis control are consolidated in Songjiang District; however, there are still risk factors of schistosomiasis transmission, including residual snails, snail diffusion and importation of external source of infection. The future surveillance of schistosomiasis should focus on snails and sources of infection.

Surveillance of schistosomiasis 34 years after transmission interruption in Songjiang District, Shanghai City / 中国血吸虫病防治杂志

Objective To analyze the surveillance data after schistosomiasis transmission interruption from 1985 to 2018, so as to provide scientific basis for the future prevention and control of schistosomiasis. Methods The data pertaining to snail survey, surveillance of schistosomiasis in humans and livestock, and health education were collected and analyzed in Songjiang District after schistosomiasis transmission interruption from 1985 to 2018. Results From 1985 to 2018, there were 8 townships, 68 villages and 1 462 settings with snails in Songjiang District, covering an area of 96.399 hm2. There were 4 townships and 59 villages with snails newly identified in previously schistosomiasis non-endemic areas, with emerging snail habitats of 60.161 hm2. A total of 26 148 snails were captured, and no infections were detected. The snail habitats were mainly distributed in the river course, ditches and farmlands, which accounted for 45.28%, 33.17% and 21.55% of total snail habitats, respectively. A total of 245 955 humans were subjected to the serological test, with a positive rate of 0.03%, and 37 humans were subjected to the parasitological test, with 3 positives detected. These three egg-positives were all imported chronic cases with schistosomiasis. A total of 9 109 livestock were detected using the serological test, and no infection was found. Most of the awareness rate of schistosomiasis control knowledge and the rate of correct behavior formation were over 80% in residents and students. Conclusions The achievements of schistosomiasis control are consolidated in Songjiang District; however, there are still risk factors of schistosomiasis transmission, including residual snails, snail diffusion and importation of external source of infection. The future surveillance of schistosomiasis should focus on snails and sources of infection.

Surveillance of schistosomiasis 34 years after transmission interruption in Songjiang District, Shanghai City / 中国血吸虫病防治杂志

Objective To analyze the surveillance data after schistosomiasis transmission interruption from 1985 to 2018, so as to provide scientific basis for the future prevention and control of schistosomiasis. Methods The data pertaining to snail survey, surveillance of schistosomiasis in humans and livestock, and health education were collected and analyzed in Songjiang District after schistosomiasis transmission interruption from 1985 to 2018. Results From 1985 to 2018, there were 8 townships, 68 villages and 1 462 settings with snails in Songjiang District, covering an area of 96.399 hm2. There were 4 townships and 59 villages with snails newly identified in previously schistosomiasis non-endemic areas, with emerging snail habitats of 60.161 hm2. A total of 26 148 snails were captured, and no infections were detected. The snail habitats were mainly distributed in the river course, ditches and farmlands, which accounted for 45.28%, 33.17% and 21.55% of total snail habitats, respectively. A total of 245 955 humans were subjected to the serological test, with a positive rate of 0.03%, and 37 humans were subjected to the parasitological test, with 3 positives detected. These three egg-positives were all imported chronic cases with schistosomiasis. A total of 9 109 livestock were detected using the serological test, and no infection was found. Most of the awareness rate of schistosomiasis control knowledge and the rate of correct behavior formation were over 80% in residents and students. Conclusions The achievements of schistosomiasis control are consolidated in Songjiang District; however, there are still risk factors of schistosomiasis transmission, including residual snails, snail diffusion and importation of external source of infection. The future surveillance of schistosomiasis should focus on snails and sources of infection.

[Risk analysis of imported schistosomiasis in Shanghai City from 2005 to 2015].

OBJECTIVE: To understand the risk situation of imported schistosomiasis and its main influencing factors in Shanghai City from 2005 to 2015. METHODS: A retrospective survey was performed, and the database was established based on the data collection of imported schistosomiasis, Oncomelania hupensis snail situation and mobile population in Shanghai City from 2005 to 2015. RESULTS: From 2005 to 2015, the mobile population in Shanghai City increased by 123.92%, which reached about 9 816 500, and 54.70% of them were located in the inner suburban districts. The accumulated areas with snails of 7.13 hm2 were found in 16 towns of 4 outer suburbs (excluding Chongming District). A total of 23 cases of imported schistosomiasis were found in Shanghai City, and the number of the imported schistosomiasis cases was on the downward trend (rs = -0.782, P = 0.004). From 2005 to 2009, 11 out of 13 imported schistosomiasis cases (84.62%) were distributed in the inner suburban districts where no O. hupensis snails were found at the same time. From 2010 to 2015, 9 out of 10 imported schistosomiasis cases (90%) were distributed in the outer suburban districts where O. hupensis snails were found at the same time. CONCLUSIONS: The number of imported schistosomiasis cases in Shanghai is on the downward trend. However, the threat of imported schistosomiasis to the prevention and control of schistosomiasis in Shanghai City should not be ignored.