Analysis of the monitoring results of nail snails in the Tongjiang River channel of Zhenjiang section on the south bank of Yangtze River from 2019 to 2023
- Author:
WANG Zhiqin
;
CHEN Xingchen
;
SHEN Xuehui
;
DAI Jianrong
;
LI Aihua
;
WANG Lin
;
LI Yefang
;
LI Zhiwei
- Publication Type:Journal Article
- Keywords:
Oncomelania hupensis;
Tongjiang River channel;
surveillance;
schistosomiasis;
transmission risk;
Zhenjiang City
- From:
China Tropical Medicine
2024;24(1):53-
- CountryChina
- Language:Chinese
-
Abstract:
Objective To timely understand the current status and distribution of nail snails (Oncomelania hupensis) in Tongjiang River channels in Zhenjiang City, providing a scientific basis for achieving the goal of eliminating schistosomiasis. Methods From 2019 to 2023, nine Tongjiang River channels on the south bank of the Yangtze River under the jurisdiction of Zhenjiang City were selected as the monitoring area. Snail monitoring was carried out onshore and beach nail snails floats in the Tongjiang River channels, nail snails on attachments in hardened areas, snails induced by straw curtains, and snails carried by boats and domestic animals. Results The monitoring results of shoreline snail from 2019 to 2023 showed that the snail situation in the Tongjiang River channel and its outer river bank remained relatively stable from 2019 to 2020; however, in 2021, under the influence of the Yangtze River flooding disaster in 2020, the area of snails increased significantly. In 2021, the area with snails in the Tongjiang River channel and the outer river bank increased by 45.70% (11.95/26.15) and 100.00% (20.00/20.00) compared to 2020; the average density of nails snails in the Tongjiang River channel and the outer river bank and the emergence rate of snail frames both showed a significant increase, rising by 94.73% (0.18/0.19) and 68.08% (8.68/12.75) compared to 2020, and by 122.73% (0.81/0.66) and 102.78% (43.26/42.09), respectively. The differences in the increase in the occurrence rate of spiked frames in the Tongjiang River channel Chili River and Renmin River were not statistically significant (χ2=0.329, P>0.05; χ2=0.646, P>0.05). From 2022 to 2023, the density of nail snails and the occurrence rate of framed snails in the Tongjiang River channel showed a decreasing trend (F=4.72, P=0.04 and χ2=372.58, P<0.01). The area of nail snails, density of live snails, and occurrence rate of framed snails in the outer river bank showed a decreasing trend (F=13.96, P=0.02; F=23.43, P<0.01; χ2=1 029.69, P<0.01). During the five years, no nail snails were detected in the ancient canal and 11 tributaries. From 2019 to 2023, 180 times of 3 003 kg of floating objects were salvaged, with a total of 148 live snails detected. A total of 17 live snails were captured on attachments in the hardened berm area; a total of 11 live snails were captured by straw curtain snail baiting;112 boats were inspected, and no snails were found; there were 112 boats surveyed, and no snails were found; 97 cattle were observed, and 2 cattle were found to carry 1 live snail on their hooves; 321 sheep were observed, and no snails were found on their hooves; and no infectious snails were found in the monitoring area in 5 years. Conclusions Nail snails continue to exist in the Tongjiang River channel, and the risk factors for schistosomiasis transmission have not been completely eliminated. It is still necessary to carry out accurate monitoring of the snail situation in the Tongjiang River and the river bank, so as to grasp the risk of transmission in time and take emergency measures.
- Full text:202502190938572648010.Analysis of the monitoring results of nail snails in the Tongjiang River channel of Zhenjiang section on the south bank of Yangtze River from 2019 to 2023.pdf
