Work

Molecular confirmation and epidemiological implications of Heterophyes heterophyes in Melanoides tuberculata from southern Thailand

Year: 2026

Type: article

Abstract: Fish-borne zoonotic trematodes remain important food-borne parasitic infections in East and Southeast Asia, where transmission depends on snail intermediate hosts in freshwater ecosystems. Surveillance of cercarial infections in freshwater snails is therefore essential for understanding local transmission dynamics and epidemiological risk. This study investigated cercarial infections in thiarid snails from southern Thailand, with emphasis on zoonotic heterophyids and transmission ecology. A total of 566 thiarid snails were examined, of which Melanoides tuberculata was the dominant species ( n = 476). Cercarial infections were detected exclusively in M. tuberculata (10/476; 2.1%). Three trematode species were identified: parapleurolophocercous cercariae of Heterophyes heterophyes and Haplorchis pumilio, and virgulate xiphidiocercariae of Loxogenes liberum. Species identification was achieved through integrated morphological examination and Internal transcript spacer 2 (ITS2) sequence analysis, which confirmed all three taxa. H. heterophyes and H. pumilio each infected a different individual snail (0.2%), with no co-infections observed, whereas L. liberum was detected in eight snails (1.7%). This study represents the first molecularly confirmed record of H. heterophyes from the freshwater thiarid snail M. tuberculata in Thailand. The findings expand the known ecological host range of this medically important heterophyid beyond its traditionally recognized brackish-water transmission system and suggest that freshwater transmission pathways may occur under suitable environmental conditions. The study further demonstrates the value of combining morphology with molecular tools for accurate identification of cercariae and highlights the importance of continued surveillance of snail-borne trematodes in endemic freshwater ecosystems.

Source: Parasite Epidemiology and Control

DOI: 10.1016/j.parepi.2026.e00553

Authors: Jirayus Komsuwan, Nuanpan Veeravechsukij, Wivitchuta Dechruksa, Kitja Apiraksena, Matthias Glaubrecht, Duangduen Krailas

Institutions: Silpakorn University, Universität Hamburg, Leibniz Institute for the Analysis of Biodiversity Change

Language: English

Topic: Mollusks and Parasites Studies

Subfield: Animal Science and Zoology

Field: Agricultural and Biological Sciences

Domain: Life Sciences

SDG: Good health and well-being

Open Access status: gold

Estimated APC paid: $1,800