Study on the prevalence of trematode cercariae infection in freshwater snails in Manipur, India.

Freshwater snails act as first intermediate carriers for numerous trematodes, which can induce sickness in both humans and animals. In Manipur, various species of freshwater snails have been discovered to harbor trematode infections. In this study, we aimed to assess the prevalence of different varieties of freshwater snail species serving as the primary, intermediate hosts for various trematodes in endemic areas of paragonimiasis, a disease caused by Paragonimus trematodes found in two separate regions, Luwangsangbam matai in the Imphal East district and Moreh in the Tengnoupal district of Manipur province. These areas are known to be endemic for human paragonimiasis. We examined 4074 snails, including Bortia costula, Filopaludina bengalensis, Paludomous pustulosa, Indoplanorbis exustus using the shedding and crushing method. Our findings revealed that 43(1.05%) snails were positive for different trematode cercariae. Specifically, Bortia costula was infected with Fasciola spp, and unidentified cercariae, while Filopaludina bengalensis and Paludomous pustulosa harboured Gymnacephalous and Echinostomous cercariae. Interestingly, Indoplanorbis exustus did not show any infection with trematode cercariae. A strong association was found between these types of snail species and cercarial infection. Furthermore, statistical analysis did not demonstrate a significant correlation between the geographical location and cercarial infection among snail species. Our study provides the current status of the prevalence of trematode cercarial infection in these snails, offering insights into disease transmission dynamics and the role of snails in paragonimiasis epidemiology.