Balanocochlis glans (Gastropoda: Thiaridae) as a New Intermediate Host of Centrocestus formosanus (Digenea: Heterophyidae) in the Philippines.

PURPOSE: Centrocestus formosanus Nishigori, 1924 is a zoonotic trematode known to cause centrocestiosis in the gills of fish and is also categorized as an intestinal trematodiosis in humans. Accurate identification of its pleurolophocercous cercariae is essential for assessing and managing public health risks. METHODS: Approximately 400 Balanocochlis glans snails were collected from the Casecnan River, Nueva Vizcaya, Luzon, Philippines. Cercariae were isolated using the crushing method and both morphological and molecular analyses (partial 28S rDNA and cox1 sequences) were performed for parasite identification. RESULTS: A total of 13.75% of B. glans individuals were found to be infected with pleurolophocercous cercariae of C. formosanus, confirmed through molecular data. CONCLUSION: The detection of C. formosanus in B. glans represents a new intermediate host record. These findings provide important baseline data for understanding the parasite's ecology and are critical for developing targeted interventions to mitigate its potential impact on aquatic ecosystems, public health, and local communities.