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Annals of Parasitology 2022Centrocestus formosanus is a zoonotic small invasive heterophyid fluke with worldwide distribution. Its three-host life cycle requires a thiarid snail as first...
Further contribution to the life history of Centrocestus formosanus (Nishigori, 1924) Price, 1932 (Trematoda: Heterophyidae) with special reference to a new first intermediate host from the South Western Ghats, India.
Centrocestus formosanus is a zoonotic small invasive heterophyid fluke with worldwide distribution. Its three-host life cycle requires a thiarid snail as first intermediate host, fishes as second intermediate hosts and piscivorous birds and mammals as definitive hosts for completion. As far as is known, the only first intermediate host being utilized, globally, by this parasite is the snail, Melanoides tuberculata. In the present study, life cycle stages of C. formosanus were recovered naturally and successfully tested in the laboratory. Study also adds a new host to its life cycle, the snail Bithynia (Digoniostoma) pulchella, as the first intermediate host with natural infection. Parasitological descriptors (prevalence, mean intensity and mean abundance) of infection were measured for each host. Being an invasive parasite, addition of a new host to C. formosanus life cycle has notable ecological and evolutionary significance.
PubMed: 37702283
DOI: 10.17420/ap6804.482 -
Emerging Infectious Diseases Nov 2022A survey of intestinal helminths targeting 1,440 schoolchildren in 12 primary schools on Kome Island (Lake Victoria), Tanzania, revealed small trematode eggs in 19...
A survey of intestinal helminths targeting 1,440 schoolchildren in 12 primary schools on Kome Island (Lake Victoria), Tanzania, revealed small trematode eggs in 19 children (1.3%), seemingly of a species of Haplorchis or Heterophyes. The eggs were molecularly confirmed to be Haplorchis pumilio on the basis of 18S and 28S rDNA sequences.
Topics: Child; Animals; Humans; Heterophyidae; Lakes; Tanzania; Trematode Infections; DNA, Ribosomal
PubMed: 36286076
DOI: 10.3201/eid2811.220653 -
Annals of Parasitology 2021Studies on distribution of parasites are important to reveal the ecology of host-parasites interactions. The objective of the study was to compare the variations in...
Spatio-temporal and host-dependent variations in prevalence and intensity of heterophyid (Digenea: Heterophyidae) metacercariae infection in brackishwater and freshwater fishes: a comparative study.
Studies on distribution of parasites are important to reveal the ecology of host-parasites interactions. The objective of the study was to compare the variations in heterophyid encysted metacercariae (EMC) infection in freshwater and brackishwater fish hosts and variation in parasitological descriptors of metacercariae infection during different seasons. The status of infection with heterophyid EMCs in the second intermediate host fishes from brackishand freshwater resources was investigated. Seasonal changes in the occurrence of EMCs in different fish hosts were monitored in a longitudinal field survey lasting 12 months from June 2018 to May 2019. Distribution of heterophyid EMCs was found varied in freshwater and brackishwater fishes with higher prevalence in brackishwater fish. There was a distinct seasonal trend in the prevalence of infection for all heterophyid EMCs in the brackishwater fish examined with high burden during summer. Thus variations in parasitic infection among hosts underpin the importance of parasites as an evolutionary or ecological force.
Topics: Animals; Fish Diseases; Fishes; Fresh Water; Heterophyidae; Metacercariae; Prevalence; Trematode Infections
PubMed: 35294142
DOI: 10.17420/ap6704.391 -
Parasitology Research Jan 2021We report for the first time the infection of dolphins with Ascocotyle longa found in the intestines of three different species, Sotalia guianensis, Steno bredanensis,...
We report for the first time the infection of dolphins with Ascocotyle longa found in the intestines of three different species, Sotalia guianensis, Steno bredanensis, and Tursiops truncatus gephyreus, which were found washed ashore along the southeastern and southern Brazilian coast. The worms were identified based on morphological and molecular data using the 28S rDNA gene and the COI gene. Specimens of A. longa from the pinniped Otaria flavescens were also analyzed. As the first isolation of A. longa from cetaceans, the present study increases the distribution area and range of definitive hosts of this trematode, and provides new molecular data to complement the phylogeny of the group in future studies, thus contributing to the scientific knowledge of this potentially zoonotic parasite.
Topics: Animals; Atlantic Ocean; Bottle-Nosed Dolphin; Brazil; Electron Transport Complex IV; Heterophyidae; Intestines; RNA, Ribosomal, 28S; Trematode Infections
PubMed: 33169307
DOI: 10.1007/s00436-020-06956-1 -
Tropical Biomedicine Jun 2020Raw or undercooked fish dishes are the major sources of human infection of fishborne trematodes (FBT) and the situation of metacercarial infection in fish greatly affect...
Raw or undercooked fish dishes are the major sources of human infection of fishborne trematodes (FBT) and the situation of metacercarial infection in fish greatly affect the prevalence in humans, especially those fish that are commonly used for raw consumption. To investigate the situation of infection with metacercaria of FBT in fish often used to prepare raw fish dishes by local people to assess the risk of infection to humans in Ninh Binh province, Vietnam. 345 fish belonging to five species of freshwater and one species of brackish water fish were collected from fishermen or small-scale fish dealers in Kim Son and Yen Khanh districts, Ninh Binh province between May 2017 and May 2018. Metacercaria of FBT was discovered by pepsin and hydrochloric acid digestion techniques and identified by the morphological and molecular analysis. Among examined fish, 44.06% infected with FBT metacercaria and the highest prevalence was in Cyprinus carpio (86.54%), Ctenopharyngodon idellus (78.43%) and Hypophthalmichthys molitrix (66.67%) while Konosirus punctatus - the brackish water fish - were free from infection. Three species of FBT were found; namely Haplorchis pumilio (accounting for 99.84% of collected metacercariae), Haplorchis taichui and Clonorchis sinensis. The average density was 1.06 metacercariae per gram of freshwater fish and the highest number was of C. idellus (6.38 cysts/gram) followed by Cirrhinus molitorella and C. carpio. Results of the study show the high prevalence of infection of FBT metacercariae among freshwater fish often used to prepare raw fish dishes in Ninh Binh province. These findings suggest the need for greater awareness of the risk from raw fish dishes among public health authorities and people.
Topics: Animals; Clonorchis sinensis; Cross-Sectional Studies; Fish Diseases; Fishes; Food Contamination; Heterophyidae; Metacercariae; Trematoda; Vietnam
PubMed: 33612813
DOI: No ID Found -
International Journal For Parasitology.... Apr 2022() n. sp. is described based on adults from experimentally infected ducklings () fed with metacercariae from the visceral serosa of the Mediterranean banded killifish,...
() n. sp. is described based on adults from experimentally infected ducklings () fed with metacercariae from the visceral serosa of the Mediterranean banded killifish, (Cyprinodontiformes: Aphaniidae), from coastal lagoons in northeastern Italy (Emilia-Romagna Region). The new species is placed into the subgenus because of the presence of a single row of circumoral spines, vitelline follicles being confined between the ventral sucker and testes, and uterine loops not reaching anterior to the ventral sucker. () n. sp. differs from other members of the subgenus , as well as other species of , by the number (27-33) of circumoral spines which are 13.5-17 μm long and 3.5-5 μm wide, and by the morphology of a gonotyl which is composed of about 8 large refractile pockets. The occurrence of metacercariae in indicates that the life cycle of the new species is completed in brackish water lagoons. It is the fourth species of described in Europe and may be endemic to the Mediterranean region because its second (fish) intermediate host is endemic to this region.
PubMed: 36117855
DOI: 10.1016/j.ijppaw.2021.10.003 -
The Korean Journal of Parasitology Dec 2021Total 513 heterophyid flukes were collected from a carcass of wild Korean raccoon dog, Nyctereutes procyonoides koreensis, in Korea. With morphological and molecular...
Total 513 heterophyid flukes were collected from a carcass of wild Korean raccoon dog, Nyctereutes procyonoides koreensis, in Korea. With morphological and molecular characteristics, the flukes were identified to Cryptocotyle lata. The adult C. lata were minute, transparent, pentagonal, 522 µm long by 425 µm wide. Ceca extended into post-testicular region. Ventrogenital sac elliptical, 79 µm by 87 µm with genital pore and ventral sucker. Two testes semielliptical and slightly lobed, located in the posterior region, right testis 173 µm by 155 µm, left testis 130 µm by 134 µm. In a phylogenetic tree, the fluke specimen of this study was grouped with C. lata divergent from Cryptocotyle lingua. We report here N. procyonoides koreensis first as a natural definitive host of C. lata.
Topics: Animals; Heterophyidae; Male; Phylogeny; Raccoon Dogs; Republic of Korea; Trematoda
PubMed: 34974672
DOI: 10.3347/kjp.2021.59.6.645 -
Revista Brasileira de Parasitologia... 2021Ascocotyle (Phagicola) longa is an etiological agent of human phagicolosis. Mugilids are the second intermediate host, the first being Heleobia australis, and mugilids...
Ascocotyle (Phagicola) longa is an etiological agent of human phagicolosis. Mugilids are the second intermediate host, the first being Heleobia australis, and mugilids predatory birds and mammals are its definitive hosts. The occurrence of cysts holding A. longa metacercariae is described in mugilids with a prevalence of up to 100%. The wide geographical distribution of A. longa and its intermediate hosts coupled with the rise in the consumption of raw or poorly cooked fish may elevate the risk of human infection. Therefore, in this study, we aimed to verify the distribution pattern of cysts holding A. longa in mugilids. The tissue and organ samples of these fish were processed in a domestic blender and examined under a stereoscopic microscope to identify the cysts holding the digenetic metacercariae. Of the 24 (100%) fish samples that were analyzed, 12 of Mugil curema and 12 of Mugil liza possessed cysts holding A. longa metacercariae. Digenetic cysts were identified to be present in the gills, heart, stomach, liver, intestines, mesentery, and muscular tissues collected from M. curema and M. liza. Conclusively, in M. curema, the cysts holding A. longa metacercariae were found to be distributed randomly throughout the fish body in almost every tissue and organ that was examined.
Topics: Animals; Cysts; Fish Diseases; Heterophyidae; Metacercariae; Smegmamorpha; Trematoda; Trematode Infections
PubMed: 34495044
DOI: 10.1590/S1984-29612021071 -
The Korean Journal of Parasitology Feb 2021The infection status of zoonotic trematode metacercariae (ZTM) was surveyed in freshwater fishes from the water systems of Geum-gang (River) in the Republic of Korea...
The infection status of zoonotic trematode metacercariae (ZTM) was surveyed in freshwater fishes from the water systems of Geum-gang (River) in the Republic of Korea (Korea). A total of 1,161 freshwater fishes from 6 local sites of Geum-gang were examined with the artificial digestion method for 4 years (2012-2015). Clonorchis sinensis metacercariae were detected in 122 (37.2%) out of 328 fishes in the positive fish species from 4 surveyed areas, and their mean intensity was 43 per fish infected. Metagonimus spp. metacercariae were found in 432 (51.7%) out of 835 fishes in the positive fish species from all 6 surveyed areas, and their mean intensity was 30 per fish infected. Centrocestus armatus metacercariae were detected in 285 (75.0%) out of 380 fishes in the positive fish species from 6 surveyed areas, and their mean intensity was 2,100 per fish infected. Echinostoma spp. metacercariae were found in 56 (19.7%) out of 284 fishes in the positive fish species from 5 surveyed areas, and their mean intensity was 10 per fish infected. Clinostomum complanatum metacercariae were detected in 98 (57.3%) out of 171 fishes in the positive fish species from only 2 surveyed areas, and their mean intensity was 11 per fish infected. Conclusively, the endemicity of ZTM is not so high in fishes from water systems of Geum-gang in Korea although it is more or less different by fish species, surveyed areas and ZTM species.
Topics: Animals; Clonorchis sinensis; Fish Diseases; Fishes; Heterophyidae; Metacercariae; Republic of Korea; Rivers; Time Factors; Trematoda; Trematode Infections; Water
PubMed: 33684984
DOI: 10.3347/kjp.2021.59.1.23 -
Gastroenterology Mar 2021
Topics: Animals; Biopsy; Child; Chronic Disease; Diarrhea; Duodenoscopy; Duodenum; Heterophyidae; Humans; Intestinal Mucosa; Male; Malnutrition; Narrow Band Imaging; Trematode Infections
PubMed: 33096101
DOI: 10.1053/j.gastro.2020.10.028