Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “TREMATODE INFECTIONS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,405 records · Page 78Linked to original sources

A comparison of Texan and Hawaiian strains of the avian eyefluke, philophthalmus gralli, with a cautionary note on the importation of exotic animals.

Philophthalmus gralli (Mathis and Leger, 1910) was introduced into the San Antonio, Texas area within the last 25-30 years from an unknown foreign source. Strains of P. gralli originally from Texas and Hawaii were compared for differences in morphology, growth patterns, mating compatibility, and isozyme mobilities. Metacercarial cysts of the 2 strains were compared for viability after storage at room temperature. Adult stages of the 2 strains were indistinguishable based on sucker ratios, vitellaria, and egg sizes. In single- and multiple-worm infections, both strains exhibited similar growth patterns when reared in chickens. Adults of the 2 strains, when transplanted in concurrent infections, readily cross-inseminated. Isozyme mobilities of 5 enzymes were identical in all adult worms examined from both strains. After 3 days, metacercarial cysts from both strains rapidly lost their ability to excyst. The cysts of the Texan strain remained viable for 4 days longer than the Hawaiian strain, although excystment rates were low during that period. The evolutionary implications of this imported species are discussed.

Animals↗

[Infection status of sweetfish from Kwangjung-stream and Namdae-stream in Yangyang-gun, Kangwon-do with the metacercariae of Metagonimus yokogawai].

This study was performed to observe the infection status of sweetfish, caught from Kwangjung-stream and Namdae-stream in Yangyang-gun, Kangwon-do in August 1989, with the metacercariae of Metagonimus yokogawai. All of 28 sweetfish from Kwangjung-stream were infected with the metacercariae of M. yokogawai. The number of metacercariae in a fish ranged 89-521(224 on average), and the number of larvae/g of flesh was 12 approximately 55 (22 on average). On the other hand, no metacercariae were detected in the fish from Namdae-stream. It has been confirmed that the Kwangjung-stream in Yangyang-gun, Kangwon-do is one of the endemic foci of metagonimiasis in Korea.

Animals↗

High annealing temperature-random amplified polymorphic DNA (HAT-RAPD) analysis of three paramphistome flukes from Thailand.

The rumen flukes of 37 cows (Bos indicus) from Chiang Mai and Lamphun provinces were investigated, and the overall prevalence of infection was 78.38% (29/37). Three species were found: Paramphistomum epiclitum, Orthocoelium streptocoelium, and Fischoederius elongatus with prevalences of infection of 75.68%, 48.65%, and 40.54%, respectively. Genomic DNA was amplified by polymerase chain reaction based on the high annealing temperature-random amplification of polymorphic DNA (HAT-RAPD) technique. Five random 10-mer oligonucleotide primers (OPA2, OPA4, OPB18, OPC9, and OPH11) produced distinct banding patterns in three species. No genetic variations in these three species were identified using 10 arbitary primers.

Animals↗

Susceptibility of eye fluke-infected fish to predation by bird hosts.

Host manipulation by trophically transmitted parasites may predispose infected hosts to predation and in this way enhance parasite transmission. In most study systems, however, the evidence comes from laboratory studies, and therefore knowledge of the effect of manipulation on parasite transmission efficiency in the wild is still limited. Here we examined the effect of Diplostomum spathaceum (Trematoda) eye flukes on the susceptibility of fish intermediate hosts to predation by bird definitive hosts. Our earlier studies have shown that the parasite alters fish phenotype and increases their susceptibility to artificial predation under laboratory conditions. In the present field study, we allowed wild birds to feed on fish from cages placed into a lake, and found that predation vulnerability of infected fish did not differ from that of controls. However, we suggest that the experimental set-up likely affected the result because the cages allowed gulls, which caught most of the fish in the study, to feed on fish in an easy, unnatural manner by standing on the edges of the cages. Nevertheless, considerable predation was observed, which provides important initial evidence of how this question should be addressed in the wild.

Analysis of Variance↗

Presence of Trichobilharzia szidati in Lymnaea stagnalis and T. franki in Radix auricularia in northeastern France: molecular evidence.

A molecular approach was used to analyse a focus of cercarial dermatitis in northeastern France (Lake Der-Chantecoq), including both cercariae and snails,by sequencing the internal transcribed spacers (ITS1 for ocellate furcocercariae and ITS2 for snails). Lymnaea stagnalis were found infected with the furcocercariae of Trichobilharzia szidati, and T. franki furcocercariae were found in Radix auricularia. The record of these two visceral parasites of birds in northern France confirms strong host-parasite relationships. The use of these standardised markers will be of the highest significance for our understanding of the epidemiology of cercarial dermatitis in this recreational lake.

Adult↗

The rate of development of Polylabroides multispinosus (Monogenea: Microcotylidae) parasitic on the gills of Acanthopagrus australis (Pisces: Sparidae).

Experiments were done to determine the rate of development of Polylabroides multispinosus. Eggs hatch after an average 9, 7 and 6 days at 20, 24 and 28 degrees C, respectively. The ciliated oncomiracidium hatched with one pair of clamps (c.p.). Juvenile worms less than 3 days post-infection (p.i.) had 2 c.p. and blood and hematin in the simple, saccular gut. The gut bifurcated at 11 c.p. (6-9 days p.i.) (24 degrees C). The genital atrium, testes, ovary and vitellaria appeared at 16 c.p. (8-11 days p.i.), 22 c.p. (10-14 days p.i.), 30 c.p. (14-18 days p.i.) and 40 c.p. (17-21 days p.i.), respectively. Eggs were produced at 20 days p.i. The period from egg deposition to egg deposition is about one month at 24 degrees C.

Animals↗

Partial characterization and isolation of 130 kDa antigenic protein of Dicrocoelium dendriticum adults.

The study focused on characterizing and isolating Dicrocoelium dendriticum antigens or their fractions that could be used for the immunological diagnosis of dicrocoeliosis. Somatic (SoAg) and excretory-secretory antigens (ESAg) were analyzed by SDS-PAGE and their specificity was evaluated by Western blot with homologous and heterologous sera. The antigens were partially purified by chromatographic techniques of gel-filtration (Sephacryl S-300) and ion exchange (Hitrap-DEAE-Sepharose). Western blot analysis using sera of ovine infected with D. dendriticum revealed eight main antigenic polypeptides ranging from 24 to 205 kDa for SoAg and seven for ESAg with apparent molecular mass in the range of 26-205 kDa. We detected a specific parasite protein with an approximate molecular weight of 130 kDa in SDS-PAGE gels, arranged as a 450 kDa tetramer in native conditions. It also showed strong immunoreactivity by Western blot against ovine sera experimentally infected with D. dendriticum. Gel filtration chromatography (Sephacryl S-300) also showed other specific proteins, one of about 24 kDa in SoAg and another of about 42 kDa in ESAg. The elution conditions of 450 kDa protein (130 kDa monomer) by DEAE chromatography were similar to those from the somatic antigen (pH 7.2, 0.1M NaCl, in 29-34 ml fractions) and from the excretion-secretion antigen (pH 8.0, 0.1M NaCl, in 29-35 ml fractions). The suitability of 130 kDa polypeptide for D. dendriticum infection diagnosis was confirmed by Western blot using a pool of sera as well as individual serum samples from experimentally infected sheep. The sequence of amino termini of 130 kDa polypeptide from both fractions was the same and identical to that reported for a peptide from D. dendriticum described as a globin. This sequence also revealed an appreciable similarity with the amino end of globins from some phylogenetically related worms.

Amino Acid Sequence↗

Host-induced morphological variability in adult Posthodiplostomum minimum (Digenea: Neodiplostomidae).

Posthodiplostomum minimum adults were collected from natural hosts at Lake Pátzcuaro, Michoacán, México and from experimentally infected hosts. Intraspecific variation was measured using principal component analysis (PCA). Morphological traits such as general body shape, size, and the specific location of certain distinctive organs and structures showed great variation among hosts as described by PCA. These results extend previous studies on host-induced variation in P. minimum in showing that some conservative traits such as vitelline follicle distribution in fore-and hindbody, could be used for an extensive and complete revision of the genus Posthodiplostomum.

Animals↗

The first human case of Clinostomum complanatum (Trematoda: Clinostomidae) infection in Korea.

The authors present the first human case of Clinostomum pharyngitis in Taegu, Korea. The patient was a 56-year old male who visited an otolaryngology clinic due to foreign body sensation and pain of the pharyngeal region for 3-4 days. He used to eat raw fresh-water fish. Otolaryngological examinations revealed a living worm adhered to the right posterior pharyngeal wall. The worm removed was identified as C. complanatum after morphological observations. It is likely that more attention should be paid to eating raw fresh-water fish in Korea with regards to Clinostomum pharyngitis.

Animals↗

Common-source outbreak of acute infection due to the North American liver fluke Metorchis conjunctus.

BACKGROUND: We investigated an outbreak of acute clinical illness among 19 people who ate raw fish (sashimi) prepared from the white sucker, Catostomus commersoni, caught in a river north of Montreal, Canada. METHODS: We collected epidemiological, clinical, laboratory, and serological data on 19 individuals who ate the sashimi and six who did not. Because of the suggestive clinical picture, we set out to recover helminth parasites from uneaten fish. FINDINGS: The illness consisted of persistent upper abdominal pain, low grade fever, high blood eosinophil concentrations, and raised liver enzymes. After 10 days, opisthorchild-like eggs were found in stools. Symptoms persisted for 3 days to 4 weeks without treatment, but responded rapidly to praziquantel therapy. Necropsy of golden hamsters infected with metacercariae from uneaten fish revealed adult flukes identified as Metorchis conjunctus. INTERPRETATION: We describe an acute illness caused by the North American liver fluke M conjunctus. This is a new human disease and is the first report of a common-source outbreak of an acute illness caused by liver flukes of the family Opisthorchiidae.

Adult↗

Host specificity among Ancyrocephalinae (Monogenoidea) of Nebraska sunfish.

This study addressed the problem of local patterns of host specificity among Ancyrocephalinae (Monogenoidea) on bass and sunfish species, when the hosts occur in different species combinations in separate ponds. One hundred fifty-three fish of the Centrarchidae, from 4 study sites in Nebraska, were collected. Host species included bluegill (Lepomis macrochirus), green sunfish (L. cyanellus), largemouth bass (Micropterus salmoides), black crappie (Pomoxis nigromaculatus), white crappie (P. annularis), and rock bass (Ambloplites rupestris). These fish occurred in different species combinations, depending on the pond sampled. Results indicated that several centrarchid species could inhabit the same pond and yet support distinct monogene communities. Clavunculus bursatus, Onchocleidus helicis, O. principalis, and Syncleithrum fusiformis were found only on largemouth bass, regardless of what other centrarchids were present in a particular pond. Haplocleidus dispar occurred on green sunfish, bluegill, largemouth bass, and black crappie, and H. furcatus occurred on both bluegill and largemouth bass. Onchocleidus cyanellus and O. ferox were found on both bluegill and green sunfish. Rock bass were present in only 1 of the 4 ponds, but were not infected with any monogenes, even though co-occurring centrarchids were often heavily infected. Largemouth bass had the most diverse ancyrocephaline communities. The degree of parasite host specificity among these monogenes was inversely related to the diversity of host species present in a particular pond. In general, the parasites were more host specific than might be inferred from the literature; parasite species did not necessarily colonize supposedly receptive host species even when the latter were present, and host relatedness was the major factor in determining whether host species shared a common parasite species.

Animals↗

Differential infectivity of Transversotrema patialense for naive fish.

The discovery of Transversotrema patialense cercariae in an aquarium harboring tropical fish triggered the present study. The purpose was to estimate the potential range of infection of local freshwater and fishpond populations by T. patialense. Experimental infection of T. patialense differed among 3 species employed: 76.5% for Tilapia zillii, 37.8% for Gambusia affinis, and none for 2 varieties of Cyprinus carpio. These patterns of infectivity are different from those published previously for T. patialense infections, and they may be attributed to the origin of the fish (temperate water vs. tropical and subtropical waters) and the size of their scales. In G. affinis, but not in the other species, worm load and fish length were closely related, and the left side harbored heavier worm burdens than the right side. Taken together, these results suggest that imported T. patialense may spread to various indigenous natural and cultured fish populations, with ensuing potential harm to these populations.

Animals↗

Distribution patterns of marine bird digenean larvae in periwinkles along the southern coast of the Barents Sea.

An important component of the parasite fauna of seabirds in arctic regions are the flukes (Digena). Different species of digeneans have life cycles which may consist of 1 intermediate host and no free-living larval stages, 2 intermediate hosts and 1 free-living stage, or 2 intermediate hosts and 2 free-living larval stages. This study examined the distribution of such parasites in the intertidal zones of the southern coast of the Barents Sea (northwestern Russia and northern Norway) by investigating 2 species of periwinkles (Littorina saxatilis and L. obtusata) which are intermediate hosts of many species of digeneans. A total of 26,020 snails from 134 sampling stations were collected. The study area was divided into 5 regions, and the number of species, frequency of occurrence and prevalence of different digenean species and groups of species (depending on life cycle complexity) were compared among these regions, statistically controlling for environmental exposure. We found 14 species of digeneans, of which 13 have marine birds as final hosts. The number of species per sampling station increased westwards, and was higher on the Norwegian coast than on the Russian coast. The frequency of occurrence of digeneans with more than 1 intermediate host increased westwards, making up a larger proportion of the digeneans among infected snails. This was significant in L. saxatilis. The prevalence of different species showed the same pattern, and significantly more snails of both species were infected with digeneans with complicated life cycles in the western regions. In L. saxatilis, environmental exposure had a statistically significant effect on the distribution of the most common digenean species. This was less obvious in L. obtusata. The causes of changing species composition between regions are probably (1) the harsh climate in the eastern part of the study area reducing the probability of successful transmission of digeneans with complicated life cycles, and (2) the distribution of different final hosts.

Animals↗

[Liver fluke infection and sarcoptic mange in red foxes in Berlin].

396 red foxes originating from the city of Berlin were examined for opisthorchiid liver flukes and clinical sarcoptic mange between January 1997 and March 1998. Out of 232 (= 58.6%) foxes positive for opisthorchiid flukes 221 animals harboured Metorchis bilis and 70 were infected with Opisthorchis felineus. Pseudamphistomum truncatum was found only in 8 foxes. M. bilis occurred as mono-infection in 154 animals. M. bilis in combination with O. felineus was found in 61 cases. Pure Opisthorchis infection as well as other fluke combinations were found in a small number of animals only. 85 (= 21.5%) foxes showed clinical sarcoptic mange. Liver fluke positive foxes showed a higher mange prevalence than uninfected animals. However, significant associations between flukes and manage were only found when comparing uninfected foxes with those having the highest worm burden. The association of liver flukes and mange could be established for adult female foxes by a significant Odds Ratio of 4.3.

Animals↗

Endemic focus of Fasciolopsis buski infection in Bangladesh.

Stool surveys were conducted on children 2--10 years of age in 27 villages within Dacca District and around this index area (1,668 children were sampled), revealing an endemic focus of Fasciolopsis buski infection to the south and the east of Dacca District. In order to determine the seasonal variation in the total snail populations and the natural rate of F. buski infection in the snails, two species of planorbid snails, Segmentina (Trochorbis) trochoideus and Hippeutis (Helicorbis) umbilicalis, were periodically sampled for 12 months from a village endemic for F. buski infection. Gymnocephalous cercariae were found in S. (T.) trochoideus snails during August, September and October. The size of the snail population (n = 1,275) was significantly correlated with inches of rainfall (r = +0.62; P less than 0.05) and water temperature (r = +0.59; P less than 0.05). The natural infection rate of F. buski in the snails ranged from 0.5--2%. Snails from non-endemic areas were exposed to 3--10 miracidia. A total of 13 of 49 (27%) of H. (H.) umbilicalis and 6 of 14 (43%) of S. (T.) trochoideus had gymnocephalous cercariae present 4 to 6 weeks after exposure to miracidia. Thus, snail strain variation is unlikely to be a barrier to F. buski transmission.

Animals↗

Intestinal fluke infections in Southeast Asia.

Twenty-three species of intestinal flukes reported in man in Southeast Asia are assigned to seven families: Echinostomatidae, Fasciolidae, Heterophyidae, Lecithodriidae, Microphallidae, Paramphistomatidae and Plagiorchiidae. The majority of species belongs to the Heterophyidae and Echinostomatidae families. Common species are Fasciolopsis buski, Echinostoma ilocanum, E. malayanum, E. revolutum and Haplorchis yokogawai. The countries where large number of species were reported are Thailand (14 species), Philippines (12 species), Indonesia (8 species) and Malaysia (4 species). Only one species was recognized in Laos, and Vietnam. Several species reported in man in the other regions, were reported in animals in Southeast Asia. It is possible that these are present in humans but have not yet been reported.

Animals↗

Cross-reactions in immunodiagnosis of patients infected with Schistosoma, Fasciola and Heterophyes using ELISA.

Cross-reactions in immunodiagnosis using schistosomal soluble egg antigen (SEA) and Fasciola adult worm antigen in cases with fascioliasis, heterophyiasis and schistosomiasis were studied by ELISA techniques. False positive reactions occurred in 10% of cases with fascioliasis and heterophyiasis respectively when using schistosomal SEA. Using Fasciola crude antigen, false positive reaction occurred in 25% of cases with schistosomiasis and 35% with heterophyiasis. The specificity of SEA in heterologous cases was 87% while that of Fasciola antigen was 70%. This difference was found to be statistically significant.

Animals↗

Opisthorchiasis and intestinal fluke infections in northern Thailand.

Four hundred and thirty-one residents from 16 provinces in northern Thailand who had previously been found positive for Opisthorchis viverrini or Opisthorchis viverrini-like eggs were given praziquantel 40 mg/kg. The stool was collected for 4 to 6 times and examined for adult worms. The prevalence of Opisthorchis viverrini in this group was 11.6%. Intestinal flukes, Haplorchis taichui and Haplorchis yokogawai, were predominantly found in 63.11% and 10.44% respectively. Other intestinal flukes (Centrocestus caninus, Echinostoma malayanum, Haplorchis pumilio, Phaneropsolus bonnei, Plagiorchid flukes, Prosthodendrium molenkampi and Stellantchasmus falcatus) were also found in small numbers.

Animals↗