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Animals : An Open Access Journal From... Dec 2023In recent years, the consumption of fish products has surged in European countries, being an essential part of a healthy diet. Despite representing a small part of EU... (Review)
Review
In recent years, the consumption of fish products has surged in European countries, being an essential part of a healthy diet. Despite representing a small part of EU production, freshwater fisheries hold considerable significance for lake-dwelling populations and tourists seeking traditional dishes. This increased fish consumption has brought to light potential health risks associated with fish-borne zoonotic helminths (FBZHs), now acknowledged as global food-borne parasites. Fish-borne zoonotic helminths belong to various taxonomic groups, including nematodes (Anisakidae), trematodes (Opisthorchiidae and Heterophyidae), and cestodes (Diphyllobothriidae). More than 50 species of FBZH are known to cause human infections, derived from eating raw or undercooked aquatic foods containing viable parasites. Despite increased attention, FBZHs remain relatively neglected compared to other food-borne pathogens due to factors like chronic disease progression and under-diagnosis. This systematic review concentrates on the prevalence of six freshwater FBZHs (, , , , , and ) in Italy and neighbouring countries. The study explores the expansion of these parasites, analysing their biological and epidemiological aspects, and the factors that influence their proliferation, such as the increased cormorant population and the lake eutrophication phenomena. In summary, this research highlights the necessity for further research, the development of spatial databases, and the establishment of a unified European policy to effectively manage these multifaceted health concerns. It strongly advocates adopting a One-Health approach to address the growing incidence of parasitic zoonoses within the context of food safety in EU countries.
PubMed: 38136832
DOI: 10.3390/ani13243793 -
Parasitology May 2021In this study of Metagonimus suifunensis (M. suifunensis) in the Russian Southern Far East, the variability of the full-length sequences of the cytochrome b (cytb) mtDNA...
In this study of Metagonimus suifunensis (M. suifunensis) in the Russian Southern Far East, the variability of the full-length sequences of the cytochrome b (cytb) mtDNA gene was assessed for the first time. In addition, the cox1 mtDNA gene sequences were also obtained for this species from new localities. In total, 87 and 81 sequences of the cytb and cox1 genes, respectively, were used in the current study. The cytb gene proved more promising and revealed two haplogroups that are associated with the spatial distribution of the species: geographical isolation caused the fixation of differences between northern and southern populations. In addition, the results obtained for the cytb gene opened up new perspectives in the analysis of sequences of the cox1 gene, which was not sufficiently effective as a sole marker. Based on data for both mitochondrial genes, molecular processes influencing the formation of the modern population were analysed for M. suifunensis. The new data confirmed the previously expressed opinion that this species colonized the study territory from north to south and will form the basis for determining possible ways of its further expansion, which is important for predicting the emergence of new foci of metagonimosis.
Topics: Amino Acid Sequence; Animals; Base Sequence; Cytochromes b; Disease Vectors; Genetic Markers; Genetic Variation; Haplotypes; Heterophyidae; Male; Rats; Rivers; Russia; Trematode Infections
PubMed: 33583451
DOI: 10.1017/S0031182021000275 -
Parasitology Research Feb 2022Freshwater snails play an essential role in the transmission of trematode parasitic flatworms that can infect wild and domestic animals, as well as humans. This study...
Freshwater snails play an essential role in the transmission of trematode parasitic flatworms that can infect wild and domestic animals, as well as humans. This study aimed to investigate the rate of cercarial infections in freshwater snails collected from two study areas, Inlay Lake and Yezin Dam, in Myanmar. A total of 4,740 snail samples were collected from Inlay Lake (n = 3,837) and Yezin Dam (n = 903), and infection rate by cercarial emergence was examined. Cercarial DNA samples were analysed by PCR. Based on morphological characteristics, eleven snail species and eight cercarial types were identified. Snails of Melanoides tuberculata in the family Thiaridae were found as the most abundant, followed by Indoplanorbis exustus of the family Planorbidae, in both study areas. The infection rate by cercarial emergence in snails in Inlay Lake and Yezin Dam was 5.8% (224/3,837) and 48.6% (439/903), respectively. Echinostome cercariae showed the highest infection rate in both study areas. Phylogenetic analysis of cercarial internal transcribed spacer 2 (ITS2) sequences revealed that at least seven cercaria types belonged to five digenean trematode families, two of which were zoonotic trematodes in the families of Opisthorchiidae/Heterophyidae and Schistosomatidae. Furthermore, cercarial 28S ribosomal RNA gene analysis showed that the furcocercous cercariae in Yezin Dam were identified as Schistosoma spindale, a causative agent of ruminant schistosomiasis. This is the first report on zoonotic trematode cercariae in snails in Myanmar. The findings indicate that various snail species act as intermediate host for trematode species that infect aquatic animals, mammals and humans in the country.
Topics: Animals; Cercaria; Humans; Lakes; Myanmar; Phylogeny; Schistosomatidae; Snails; Trematoda; Trematode Infections
PubMed: 35032219
DOI: 10.1007/s00436-022-07428-4 -
Journal of Helminthology Jul 2022The assassin snail genus is widespread in Southeast Asia, and is distributed all over the world via the aquarium trade. One species of genus , , is known to act as...
The assassin snail genus is widespread in Southeast Asia, and is distributed all over the world via the aquarium trade. One species of genus , , is known to act as intermediate host of parasitic trematodes. This study investigates the taxonomic diversity of larval trematodes infecting . and in Thailand. Larval trematodes were identified by combining morphological and DNA sequence data (cytochrome oxidase I and internal transcribed spacer 2). Species delimitation methods were used to explore larval trematode species boundaries. A total of 1107 specimens of sp. were collected from 25 localities in Thailand. Sixty-two specimens of . ( = 33) and . ( = 29) were infected by zoogonid cercariae, heterophyid metacercariae and echinostome metacercariae, with an overall prevalence of 5.6% (62/1107) and population-level prevalences in the range of 0.0-22.3%. DNA sequence data confirmed that the larval trematodes belong to the families Echinostomatidae, Heterophyidae and Zoogonidae. As such, this is the first report of zoogonid cercariae and heterophyid metacercariae in . , and echinostome metacercariae in . . Moreover, this study provides evidence of tentative species-level differentiation between Thai sp. and Cambodian , as well as within , and .
Topics: Animals; Cercaria; Echinostoma; Humans; Larva; Metacercariae; Snails; Thailand; Trematoda
PubMed: 35894430
DOI: 10.1017/S0022149X22000463 -
Parasites, Hosts and Diseases May 2023The present study aimed to determine the infection status of trematode metacercariae and adults in cyprinoid fish from the Khun Thale Swamp in Surat Thani, Southern...
The present study aimed to determine the infection status of trematode metacercariae and adults in cyprinoid fish from the Khun Thale Swamp in Surat Thani, Southern Thailand, with epidemiologic and faunistic viewpoints. In 2020, 577 fish in 15 species were collected in the summer (February-April) and rainy (September-November) seasons. Fish were individually examined for trematode metacercariae in the whole body and adults in the gastrointestinal tract using a stereomicroscope. Three species of digenetic trematode metacercariae, i.e., Haplorchis taichui, Haplorchoides mehrai, and Centrocestus formosanus, were detected in the muscle, fin, and/or scale of fish. Two species of adult flukes, including Rohdella siamensis and Helostomatis cyprinorum, were collected in the intestines. The prevalence of overall trematode infections was 32.4% (187/577 fish), which was higher in the rainy season (41.4%; 118/285) than in the summer season (23.6%; 69/292). The metacercariae of H. taichui and H. mehrai were detected in 7 fish species each, and those of C. formosanus were found only in Rasbora toneri. The aspidogastrean trematode R. siamensis (adult) was detected in Babonymus gonionotus. A digenean species, H. cyprinorum (adult), was found in Labiobarbus siamensis and Osteochilus vittatus. The present study has first confirmed that the metacercariae of heterophyid flukes, including H. taichui, H. mehrai, and C. formosanus, and adults of R. siamensis (Aspidogastrea) and H. cyprinorum (Digenea) are infected in some species of the cyprinoid fish from the Khun Thale Swamp in Surat Thani, Thailand.
Topics: Animals; Metacercariae; Thailand; Wetlands; Fish Diseases; Trematoda; Heterophyidae; Cypriniformes
PubMed: 37258263
DOI: 10.3347/PHD.23030 -
International Journal For Parasitology Nov 2019The complete cox1 gene sequence was analysed for Metagonimus suifunensis from eight localities in the Russian southern Far East, and the level of variability was...
The complete cox1 gene sequence was analysed for Metagonimus suifunensis from eight localities in the Russian southern Far East, and the level of variability was compared with that of Clonorchis sinensis from the same territory of Russia. These species belong to the superfamily Opisthorchioidea, have a similar distribution in the Russian southern Far East and share second intermediate and definitive hosts, but are distinguished by their first intermediate hosts belonging to different orders of caenogastropods. The data obtained showed that the nucleotide sequence variability of the M. suifunensis cox1 gene was significantly lower. This fact is considered in connection with a recent bottleneck passage for the M. suifunensis population, in contrast to C. sinensis, which could be due to the features of the Metagonimus life cycle under seasonal freezing temperatures, as well as historical geological and climatic changes in the Russian Far East. These factors could influence the microevolutionary processes and lead to a decrease in the level of variability in the M. suifunensis population. Based on the combination of genetic data and historical geo-processes in the region, the probable route of M. suifunensis expansion from the northern part of its current area in the Amur River basin to the southern territories of the Russian Far East is justified.
Topics: Animals; Clonorchis sinensis; Electron Transport Complex IV; Genetic Variation; Heterophyidae; Siberia
PubMed: 31628936
DOI: 10.1016/j.ijpara.2019.07.004 -
Acta Tropica Aug 2021Heterophyidiasis is a fish-borne zoonotic disease that is considered to be an emerging public health problem in the Philippines. This study was carried out to determine...
Heterophyidiasis is a fish-borne zoonotic disease that is considered to be an emerging public health problem in the Philippines. This study was carried out to determine the spatial distribution and risk factors of heterophyidiasis in five selected villages in New Corella, Davao del Norte in Southern Mindanao. Of the 1,101 individuals examined, 26 (2.36% overall prevalence rate, 95% CI 1.46-3.25) were positive for heterophyid eggs. Higher infection rate was observed in males (3.85%, 95% CI 2.27-5.43) than females (0.76%, 95% CI 0.02-1.5). Mapping of cases was done to show the spatial distribution of heterophyidiasis in New Corella. Multiple logistic regression analysis showed that gender, raw freshwater fish consumption, undercooked grilled fish consumption and proximity to rivers or creeks are the risk factors significantly associated with heterophyid infection. This study confirmed the presence of heterophyid infection in humans in the surveyed villages in New Corella in Southern Philippines.
Topics: Adolescent; Adult; Age Factors; Animals; Child; Child, Preschool; Cross-Sectional Studies; Diet; Female; Fishes; Fresh Water; Heterophyidae; Humans; Male; Middle Aged; Philippines; Prevalence; Risk Factors; Sex Factors; Socioeconomic Factors; Spatial Analysis; Trematode Infections; Young Adult
PubMed: 33932365
DOI: 10.1016/j.actatropica.2021.105940 -
The Korean Journal of Parasitology Jun 2021In this study, we intended to describe an unrecorded species of heterophyid trematode recovered from the small intestine of a Korean raccoon dog, Nyctereutes...
In this study, we intended to describe an unrecorded species of heterophyid trematode recovered from the small intestine of a Korean raccoon dog, Nyctereutes procyonoides koreensis, in Korea. A total of 13 small flukes were collected from a deceased Korean raccoon dog which was found in Chuncheon-si, Gangwon-do, Korea in May 2017. The trematode body were covered with many small spines, rectangular, broader than long, 807-1,103 µm long and 1,270-1,550 µm wide. Oral sucker in the anterior end slightly smaller than acetabulum. Pharynx muscular and well developed. Esophagus relatively long and sigmoid. Acetabulum small and located at median in anterior 2/5 portion. Ceca bifurcated at the anterior of genital pore and acetabulum and terminated at testis level. Testes larger, deeply lobed and located at the near of posterior end of body. Ovary small, triangular and located at the slight left of median and the anterior of left testis. Vitelline follicles dendritic and extend from the middle level of esophagus to the posterior portion of body. Eggs embryonated, operculated, small and 33-35×15-16 µm in size. Based on the morphological characteristics, the small heterophyid flukes recovered from the small intestines of Korean raccoon dog, N. procyonoides koreensis, were identified as Euryhelmis squamula (Digenea: Heterophyidae). Accordingly, this species of heterophyid flukes is to be a new trematode fauna in Korea by this study.
Topics: Animals; Female; Heterophyidae; Male; Raccoon Dogs; Republic of Korea; Trematoda
PubMed: 34218603
DOI: 10.3347/kjp.2021.59.3.303 -
Anais Da Academia Brasileira de Ciencias 2021Centrocestus formosanus is a digenean parasite first described from Asia, which parasitizes Melanoides tuberculata (Gastropoda: Thiaridae) at the first intermediate...
Centrocestus formosanus is a digenean parasite first described from Asia, which parasitizes Melanoides tuberculata (Gastropoda: Thiaridae) at the first intermediate stage, and different fish species as second intermediate host. C. formosanus was previously recorded in Brazilian states, but never before in the southern region of this country. Recording and identification of digenean species through morphological identification is a taxonomic challenge. In light of this, we use an integrative taxonomic approach to report the occurrence of cercariae and metacercariae of C. formosanus in molluscs and fish, respectively, in an urban park located in southern Brazil. Specimens of M. tuberculata and the fishes Poecilia reticulata and Xiphophorus sp. (Poeciliidae) were collected for screening for parasites and molecular analyses using partial fragments of the 28S rDNA gene. The identification of C. formosanus obtained from molluscs and fish specimens permitted us to partially solve the life cycle of this parasite for the first time in the studied environment, demonstrating the necessity of monitoring and controlling molluscs populations. Nevertheless, our results will support future studies aiming to elucidate the life-cycle of C. formosanus in this region, since all sampled hosts' species are invasive in this environment.
Topics: Animals; Brazil; Fish Diseases; Heterophyidae; Trematoda; Trematode Infections
PubMed: 34406283
DOI: 10.1590/0001-3765202120191017 -
Journal of Helminthology Jan 2020Eurytrema coelomaticum is a digenean flatworm of ruminants that is the causative agent of eurytrematosis, a disease of veterinary health concern. Although modern...
Eurytrema coelomaticum is a digenean flatworm of ruminants that is the causative agent of eurytrematosis, a disease of veterinary health concern. Although modern techniques of morphological analysis have provided new insights about the morphology and anatomy of parasitic helminths, most studies on E. coelomaticum adults are based on conventional light microscopy. In the present study, a combined approach using brightfield, fluorescence, confocal and scanning electron microscopies (SEMs), together with the cryofracture technique, have updated morphological data on E. coelomaticum recovered from cattle in Rio de Janeiro State, Brazil. Light microscopy confirmed the presence of several structures present in the current description, such as suckers, pharynx, oesophagus, intestinal bifurcation and the cirrus-sac. Fluorescence stereomicroscopy revealed for the first time the cubic crystal protein inclusions in the forebody, which were further detailed by confocal and SEMs. Confocal microscopy provided detailed information of the muscular architecture associated with the attachment structures (suckers), digestive system (pharynx and oesophagus), egg-forming complex (ovary, Mehlis' gland and Laurer's canal) and male reproductive system, which are similar to those found in other digenean flukes. SEM images of cryofractured parasites showed mucus and developing eggs within uterine loops. It was demonstrated that the combination of advanced tools generated complementary information, confirming the importance of experimental morphology in parasitology. Therefore, the knowledge of the adult structural organization of E. coelomaticum was improved and this work has contributed to propose new morphological criteria to evaluate the effects of antiparasitic drugs on flukes of medical and veterinary importance.
Topics: Animals; Cattle; Cattle Diseases; Eggs; Female; Genitalia; Heterophyidae; Male; Microscopy, Confocal; Microscopy, Electron, Scanning; Platyhelminths; Trematode Infections
PubMed: 31964430
DOI: 10.1017/S0022149X19001135