[Study on Oncomelania hupensis snails infected with Schistosoma japonicum miracidia under different conditions in snail-existent non-endemic areas of schistosomiasis in Nantong City]

Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi. 2017 Dec 18;29(6):784-787. doi: 10.16250/j.32.1374.2017150.
[Article in Chinese]

Abstract

Objective: To understand the forming cause of the Oncomelania hupensis snail-existent non-endemic areas of schistosomiasis (SENEAS), and to verify the conclusion of previous studies, so as to provide the evidence for schistosomiasis monitoring in such areas in Nantong City, Jiangsu Province.

Methods: The controlled field tests were carried out to observe the O. hupensis snails artificially infected by schistosome miracidia in SENEAS. The influence of the soil from SENEAS and the endemic areas on O. hupensis snails artificially infected by miracidia were observed.

Results: All the experimental snails could be infected by schistosome miracidia except the smooth-shell snails from Tangyuan Village in the controlled field test environment of SENEAS or the endemic areas. The infection rates of the smooth-shell snails were lower than those of the ribbed-shell snails, but there were no statistically significant differences. The mortality rates of the smooth-shell snails were higher than those of the ribbed - shell snails, which were statistically significant (χ2Xindian = 135.118, χ2Shuangdian = 122.836, χ2Baipu =154.436, χ2Dingyan = 138.288, χ2Control = 151.923, all P < 0.01). There were no significant differences in the infection rates of snails between each test group of the soil from SENEAS and the endemic areas (χ2Rugao = 0.071, χ2Rudong = 0.216, both P > 0.05). Also there was no significant difference between each test group and the control group without soil (χ2 = 7.148, P > 0.05).

Conclusions: It is likely to form the spread of schistosomiasis in SENEAS in Nantong City with sufficient amount of infection source of schistosomiasis imported. It is still necessary to implement the surveillance of schistosomiasis and O. hupensis snails in Nantong City.

[摘要]目的 探索南通市有钉螺无血吸虫病流行的原因, 验证既往研究结论, 为该类地区血吸虫病监测提供科学依据。 方法 采用控制现场试验方法, 现场观察人工输入血吸虫毛蚴感染钉螺情况, 同时实验室比较观察“有螺无病”和 “有螺有病”区土壤对血吸虫毛蚴感染钉螺的影响。 结果 除如东县新店镇汤园村 (有螺无病) 现场光壳螺组外, 实验钉螺在“有螺无病”和“有螺有病”现场控制环境均可以被血吸虫毛蚴感染。 各组光壳钉螺感染率低于肋壳钉螺, 但无统计学意义; 各组光壳钉螺死亡率高于肋壳钉螺, 差异有统计学意义 (χ2 = 135.118, χ2 = 122.836, χ2 = 154.436, χ2 = 138.288, χ2 = 151.923, P均< 0.01)。 “有螺无病”和“有螺有病”区土壤试验组钉螺感染率差异无统计学意义 (χ2 = 0.071, χ2 = 0.216, P均 > 0.05), 各组与无土实验对照组差异亦无统计学意义 (χ2 = 7.148, P > 0.05)。 结论 南通地区“有螺无病”区在输入足够数量血吸虫病传染源后有可能形成血吸虫病的传播, 有必要开展血吸虫病和钉螺监测工作。.

Keywords: Miracidium; Oncomelania hupensis; Schistosomiasis; Snail-existent non-endemic area of schistosomiasis (SENEAS).

MeSH terms

  • Animals
  • China
  • Cities
  • Disease Vectors
  • Environment
  • Schistosoma japonicum
  • Schistosomiasis japonica*
  • Snails / parasitology*