Discovery of Carcinogenic Liver Fluke Metacercariae in Second Intermediate Hosts and Surveillance on Fish-Borne Trematode Metacercariae Infections in Mekong Region of Myanmar

Abstract

Countries of lower Mekong regions are highly alarmed by the spread of fish-borne trematode infections, i.e., small liver flukes and minute intestinal flukes especially in Thailand, Lao People’s Democratic Republic (Lao PDR), Vietnam, Cambodia and Myanmar. Moreover; the incidence of cholangiocarcinoma has also been increasing in the endemic area of liver fluke infections. Only a few reports have been published concerning the fish-borne trematodes infections in the central region of Myanmar. However; there is still a lack of information regarding the status of trematodes infections in second intermediate hosts in the Mekong region of Myanmar. Therefore, we conducted surveillance on the distribution of trematode metacercariae in small cyprinoid fishes collected from the Mekong region of Myanmar. A total of 689 fishes (12 different species of cyprinoid fishes) have been collected and examined by pepsin digestion methods. We discovered four species of fish-borne trematode metacercariae infections, i.e., carcinogenic liver fluke, Opisthorchis viverrini; minute intestinal flukes, Haplorchis taichui; Haplorchis pumilio and Haplorchoides sp. in Tachileik, the Mekong Region of Myanmar. The outcome of this study could be a useful index for the fish-borne zoonotic trematode epidemiology in the Mekong area. Besides, the results of our study contribute to filling the gap of information necessary for the control and prevention of fish-borne trematode zoonotic infections in the Mekong region.

Parasite Diversity in a Freshwater Ecosystem

“…A small amount of sediment was transferred to a Petri dish in which physiological saline (6–7 mL) was present. A stereomicroscope and light microscope were used to count and identify the metacercariae on the basis of the shape of cysts, size of suckers, and shape of the excretory bladder, according to [ 34 , 35 , 36 ]. Photographs of the identified trematode parasites are shown in Figure 1 b.…”

“…The identification of the examined protozoan, monogenean, and trematode parasite was completed using the standard keys [ 9 , 31 , 33 , 34 , 35 , 36 , 37 ].…”

A relatively high zoonotic trematode prevalence in Orientogalba ollula and the developmental characteristics of isolated trematodes by experimental infection in the animal model

“…Epidemiological investigation presumed that fish mint consumption was most likely the cause of the infections, and the trematode shed from the snail hosts was the causative agent. In fact, similar cases related to the practice of dining on raw vegetables have also occurred in Myanmar, Thailand, Northeast Ethiopia, and other countries [9,16,17]. Guangxi Zhuang Autonomous Region is contiguous to Yunnan Province and has similar climate conditions.…”

“…Preliminary snail identification was based on morphological characters using standardized taxonomic keys as described by Liu [12]. Meanwhile, the snail identifications were confirmed by the internal transcribed spacer 1 (ITS1) sequence as described by Correa et al [17] using at least 20 samples randomly selected from one site. The foot and soft body tissue of identified O. ollula were necropsied for trematode larvae (rediae, cercariae, or metacercariae).…”

Record of Metacercariae of Paragonimus Braun, 1899 (Platyhelminthes: Trematoda) in the Amazon Province: The Second Alert of Trematodes as Potential Risk to Human Health in the State of Pará, Brazil

“…Trematodes of the family Paragonimidae Dollfus, 1939 are widely reported in the literature as parasites in several species of invertebrates (intermediate hosts) and vertebrates, including humans (final host) (DIAS et al, 2003). Within this family, the genus Paragonimus Braun, 1899 is recorded as the endoparasites of mollusks, crustaceans, fish, birds, rodents, bats, cats, dogs, and humans, which can be parasitized by the consumption of undercooked crab and fish (PHYO MYINT et al, 2020;MARTINS et al, 2023).…”