Yupa ChusongsangPhiraphol ChusongsangSuwalee WorakhunpisetZhiyue LvYanin LimpanontFaculty of Tropical Medicine, Mahidol UniversitySun Yat-Sen UniversityHainan Medical University2022-08-042022-08-042021-03-25Southeast Asian Journal of Tropical Medicine and Public Health. Vol.52, No.2 (2021), 259-27326975718012515622-s2.0-85119936445https://repository.li.mahidol.ac.th/handle/20.500.14594/78345A field study was conducted to investigate monthly variations in cercarial trematode infections in Bithynia siamensis siamensis snails in an Opisthorchis viverrini-endemic area of Chachoengsao Province, Thailand. A total of 45, 511 snails collected each month from September 2010 to August 2011, were examined for trematode infection, resulting in overall 0.10, 4.94, 1.03, and 0.01% prevalence of O. viverrini, xiphidiocercaria, amphistome, and furcocercous cercaria, respectively in B. s. siamensis. Highest prevalence of O. viverrini (0.33%) and amphistome (2.13%) were observed during the dry season (mid-February to mid-May) when rice paddies were dry, while highest prevalence of xiphidiocercaria (7.92%) occurred in the rainy season (mid-May to mid-October) when rice paddies were flooded. Monthly snail density ranged from 8.40 snails/m2 as observed in January 2011 to 32.39 snails/m2 observed in November 2010. These observations indicated dynamics of B. s. siamensis snail intermediate host of liver flukes in central Thailand depended on population density, cercarial trematode prevalence and ecology.Mahidol UniversityMedicineArticleSCOPUS