Research on the effects of environmental factors influenced by climate change on parasite transmissibility is an area garnering recent attention worldwide. However, there is still a lack of studies on the life cycle of Opisthorchis viverrini, a carcinogenic trematode found in countries of the Lower Mekong subregion of Lao PDR, Cambodia, Myanmar, Vietnam and Thailand. To evaluate the influences of environmental factors water temperature and salinity on the transmissibility of the liver fluke O. viverrini through cercarial stage, longevity of O. viverrini cercaria was examined at different experimental temperatures (22°C, 30°C and 38°C) and salinities (2.5 parts per thousand (PPT), 3.75 PPT and 5 PPT). The results reveal that different temperatures have statistically significant effects on cercarial longevity. The cercariae exhibited a thermostability zone ranging between 22°C and 30°C. Cercarial longevity was significantly shortened when water temperatures reached 38°C. Salinity also plays a key role in cercarial longevity, with cercarial survival significantly shorter at a salinity of 3.75 PPT than at 2.5 PPT and 5 PPT. A combined analysis of salinity and temperature revealed unique trends in cercarial longevity. At all experimental salinities, cercarial longevity was lowest when incubated in 38°C, but statistically significant from cercarial longevity at temperatures of 22°C and 30°C, and salinities of 2.5 PPT and 5 PPT. The results suggest that higher temperatures negatively impact parasite longevity. This reflects that O. viverrini transmission patterns may be impacted by changes in water temperature and salinity resulting from climate change.

中文翻译：

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温度和盐度对 Opisthorchis viverrini cercariae 寿命的影响：气候变化问题

研究气候变化影响的环境因素对寄生虫传播能力的影响是近年来全球关注的一个领域。但是，关于生命周期的研究还很缺乏。后鲎，一种致癌吸虫，在老挝人民民主共和国、柬埔寨、缅甸、越南和泰国的湄公河下游次区域国家发现。评价环境因素水温和盐度对肝吸虫传播能力的影响O. viverrini通过宫颈期，长寿O. viverrini在不同的实验温度（22°C、30°C 和 38°C）和盐度（2.5 ppm (PPT)、3.75 PPT 和 5 PPT）下检查尾蚴。结果表明，不同温度对尾蚴寿命的影响具有统计学意义。尾蚴表现出一个介于 22°C 和 30°C 之间的热稳定性区。当水温达到 38°C 时，子宫颈的寿命显着缩短。盐度在尾蚴寿命中也起着关键作用，3.75 PPT 盐度下的尾蚴存活时间明显短于 2.5 PPT 和 5 PPT。盐度和温度的综合分析揭示了尾蚴寿命的独特趋势。在所有实验盐度下，在 38°C 下孵育时，尾蚴寿命最低，但在 22°C 和 30°C 温度下的尾蚴寿命具有统计学意义，和 2.5 PPT 和 5 PPT 的盐度。结果表明，较高的温度会对寄生虫的寿命产生负面影响。这反映了O. viverrini传播模式可能会受到气候变化导致的水温和盐度变化的影响。