TREMATODE INFECTION IN FRESHWATER SNAILS FROM MAHA SARAKHAM PROVINCE, THAILAND

Naruemon Bunchom1, Warayutt Pilap1, Warong Suksavate2, Kotchaphon Vaisusuk3, Narufumi Suganuma4, Takeshi Agatsuma4, Trevor N. Petney5 and Weerachai Saijuntha1

Abstract

Several trematode species utilize freshwater snails as intermediate hosts. The transmission stage of trematodes from the snail host to their next intermediate or final host involves cercarial and metacercarial stages. Thus, it is important to survey trematode infections in species of freshwater snails in human and/or animal endemic regions. Prevalence and types of trematode cercariae and metacercariae found in common freshwater snails in Maha Sarakham Province, Northeast Thailand were determined. Freshwater snails (n = 3,757) collected from canals, ponds and paddy fields at 51 sites belonged to six species, namely, Bithynia siamensis goniomphalos (Morelet, 1866) (prevalence = 60.8%, trematode infection =15.2%), Filopaludina martensi (Frauenfeld, 1865) (prevalence = 13.4%, trematode infection = 0.6%), Indoplaborbis exustus (Deshayes, 1834) (prevalence = 8.6%, trematode infection =1.6%), Melanoides tuberculata (Müller, 1774) (prevalence = 8.8%, trematode infection = 4.8%), Pomacea canaliculata (Lamarck, 1819) (prevalence = 3.3%, trematode infection = 0%), and Radix rubiginosa (Michelin, 1831) (prevalence = 5.1%, trematode infection = 6.8%), with nine and eight different types of cercariae and metacercariae respectively. The most common trematodes were xiphidio and longifurcate-pharyngeate (strigea) cercariae, while highest infection rate (5.24%) was with echinostome cercaria. These findings indicate freshwater snails in Maha Sarakham Province act as both first and second intermediate hosts of several trematode species of medical and veterinary importance.