The Effects Of Temperature And Salinity On The Longevity Ofopisthorchis Viverrinicercariae: A Climate Change Concern

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 ofOpisthorchis 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 flukeO. viverrinithrough cercarial stage, longevity ofO. viverrinicercaria was examined at different experimental temperatures (22 degrees C, 30 degrees C and 38 degrees 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 degrees C and 30 degrees C. Cercarial longevity was significantly shortened when water temperatures reached 38 degrees 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 degrees C, but statistically significant from cercarial longevity at temperatures of 22 degrees C and 30 degrees C, and salinities of 2.5 PPT and 5 PPT. The results suggest that higher temperatures negatively impact parasite longevity. This reflects thatO. viverrinitransmission patterns may be impacted by changes in water temperature and salinity resulting from climate change.