Edible viviparid snails are suspected to be the source of human echinostomiasis in Thailand, but little is known about the prevalence of viviparid snail parasitization by echinostomes in snails sold for human consumption in wet markets. Here, the prevalence of echinostome metacercariae and the association between parasitic intensity and host size, as well as the relationship to host species, were investigated. In total, 1100 viviparid snails belonging to four species (Cipangopaludina annandalei, Filopaludina martensi martensi, F. sumatrensis polygramma and F. doliaris) were obtained from wet markets in Chiang Rai Province, Northern Thailand. All snail species were found to be infected with echinostome metacercariae with total prevalence and mean intensity values of 16.5% and 16.4, respectively. The metacercariae of the avian trematode, Thapariella anastomusa were found in Filopaludina spp. snails. Interestingly, C. annandalei identified in this study had not previously been considered a food source and this is the first report of echinostome metacercaria in this snail species. Results confirmed the role of C. annandalei as the second intermediate host of the trematode; however, the species identity of these echinostomes remains unclear. Comparative morphology of these metacercariae and their adult stage require further study, and molecular markers are necessary to confirm their identification. Prevalence and intensity of echinostomes metacercariae was significantly associated with snail species.

中文翻译：

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从泰国北部湿货市场获得的食用胎生蜗牛中的蜗牛传播的人畜共患吸虫

食用胎生蜗牛被怀疑是泰国人类棘口虫病的源头，但人们对在湿货市场出售供人类食用的蜗牛中的棘口虫寄生胎生蜗牛的流行情况知之甚少。在这里，研究了棘口囊蚴的流行和寄生强度与宿主大小之间的关系，以及与宿主物种的关系。总共有 1100 只胎生螺，分属于 4 个物种（Cipangopaludina annandalei,鲶鱼,F. sumatrensis polygramma和F. doliaris) 是从泰国北部清莱府的湿货市场获得的。发现所有蜗牛物种都感染了棘口囊蚴，总患病率和平均强度值分别为 16.5% 和 16.4。禽吸虫的囊蚴，螳螂被发现于菲洛帕卢迪纳spp. 蜗牛。有趣的是，C.安南达莱在这项研究中发现的之前未被认为是食物来源，这是该蜗牛物种中棘口囊蚴的第一份报告。结果证实了作用C.安南达莱作为吸虫的第二中间宿主；然而，这些棘口动物的物种身份仍不清楚。这些囊蚴的比较形态及其成虫阶段需要进一步研究，分子标记对于确认它们的鉴定是必要的。棘口囊蚴的流行率和强度与蜗牛种类显着相关。