Vet World   Vol.17   February-2024  Article-21

High prevalence of natural infection by the ruminant blood fluke Schistosoma spindale in the intermediate snail host Indoplanorbis exustus in Uttaradit, Northern Thailand

Background and Aim: Freshwater snails belonging to the family Planorbidae serve as the first intermediate hosts of many species of important parasitic flukes of animals and humans. Information regarding the occurrence of planorbid snail larval trematode infection is limited in Northern Thailand. Thus, this study aimed to estimate the prevalence of larval trematode infection of the freshwater snail Indoplanorbis exustus in Uttaradit, Thailand, and to identify trematode species based on their morphological and molecular characteristics.

Materials and Methods: Planorbid snail specimens were collected from a water reservoir in Uttaradit, Thailand, from June to August 2023. Snails were assessed for larval trematode infection through cercarial shedding and crushing methods. The released cercariae were preliminarily identified on the basis of their morphological characteristics. In addition, species identification of the detected cercariae was conducted using 28S ribosomal RNA and cytochrome c oxidase subunit 1 gene sequence analyses.

Results: The overall prevalence of cercarial infection was 61.5% (107/174) in planorbid snails in Uttaradit province. Two species of cercarial trematodes, Schistosoma spindale (106/174, 60.9%) and Artyfechinostomum malayanum (1/174, 0.6%), were identified using morphological and molecular analyses, of which S. spindale was the most abundant species. Our studied snails did not have mixed infection with more than two cercarial species.

Conclusion: Our findings reveal a remarkably high prevalence of S. spindale cercariae infecting planorbid snails in Uttaradit, indicating that humans and animals across the study area are at risk of infection. Our data may contribute to the development of effective strategies to control this zoonotic infectious disease. Keywords: Artyfechinostomum malayanum, cercaria, cercarial dermatitis, Indoplanorbis exustus, Planorbid snails, Schistosoma spindale.

Keywords: Artyfechinostomum malayanum, cercaria, cercarial dermatitis, Indoplanorbis exustus, Planorbid snails, Schistosoma spindale.

How to cite this article: Phuangsri C, and Japa O (2024) High prevalence of natural infection by the ruminant blood fluke Schistosoma spindale in the intermediate snail host Indoplanorbis exustus in Uttaradit, Northern Thailand, Veterinary World, 17(2): 413–420.

Received: 06-10-2023  Accepted: 29-01-2024     Published online: 20-02-2024

Corresponding author: Ornampai Japa   E-mail: ornampai.ja@up.ac.th

DOI: 10.14202/vetworld.2024.413-420

Copyright: Phuangsri and and Japa, et al. This article is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http:// creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.