Molecular Characterization of Fasciola and Dicrocoelium Species Isolated from Ruminant Livestock in Qazvin, Iran

INTRODUCTION

Fascioliasis and dicrocoeliasis are the most frequent zoonotic diseases with increasing human health problems in different parts of Iran. Two species, Fasciola hepatica (F. hepatica) and Fasciola gigantica (F. gigantica), are spread in the country. Molecular approaches have a decisive role in identifying both the species. The aim of this study was to detect Fasciola spp. and Dicrocoelium spp. by amplifying the ITS-2 and 28S rDNA gene sequence.

METHODS

Overall, 30 infected liver samples were collected from the livestock of Qazvin, Iran. The adult flukes were collected from different livestock. DNA extraction and PCR amplification of ribosomal RNA gene region (ITS2) and 28S rDNA gene fragment were conducted and a phylogenetic tree was constructed.

RESULT

All the isolates obtained from the cattle (No: 7) and 82.6% (No: 19) of sheep isolates were infected with F. hepatica species, whereas 17.4% (No: 4) of sheep isolates were infected with F. gigantica. It was also shown that F. hepatica was the predominant species of Fasciola present in the region. All the specimens were infected with Dicrocoelium dendriticum (D. dendriticum).

CONCLUSION

Both the species of Fasciola were found in Qazvin. D. dendriticum was the sole infecting species of the Dicrocoelium genus in the livestock of the city of Qazvin. Further research studies are needed to determine the intermediate host of the parasites in the region.

Hepatic Dicrocoelium dendriticum infection in a miniature horse

A miniature horse which died following humane seizure from an Ontario farm was emaciated with serous atrophy of fat. Autopsy revealed hepatic atrophy and moderate periportal fibrosis. Eggs and trematodes seen in the liver were identified as Dicrocoelium dendriticum. This appears to be the first reported case of infection of equids in North America with Dicrocoelium dendriticum.

Comparison of Fecal Egg Counts and ELISA for the Diagnosis of Dicrocoelium Dendriticum Infection

From economical point of view, Dicrocoelium Dendriticum (D. dendriticum) causes a lot of damages to the livestock industry annually. So, the rapid diagnosis of infection is very important. The diagnosis is based on egg per count of feces (EPG) test because detection according to clinical symptoms is difficult. Since EPG is not accurate and sensitive, the serological methods become important for the diagnosis of this parasite as they are more accurate in comparison to EPG test and they are able to diagnose infection in a short time. In this study, somatic and Excretory-secretory antigens (EsAg) were isolated. The ELISA test was set up according to positive and negative sera and the results which were obtained compared to those obtained by the EPG test. The prevalence of infection in 550 samples by ELISA and EPG methods were 56% and 7% respectively, which shows the significant difference between these methods in examining the rate of infection. Based on the results, the specificity and sensitivity in ELISA test were 95% and 94%, respectively. The results showed that the ELISA is a more reliable test in comparison to EPG test for the rapid diagnosis of D. dendriticum infection.

Predicting risk habitats for the transmission of the small liver fluke, Dicrocoelium dendriticum to grazing ruminants

A multiple regression model was used to analyse if the structure of vegetation and soil patches in grazed units (pastures) can be used as explanatory variables to predict the prevalence of Dicrocoelium dendriticum, a common parasite of cattle and sheep, in grazing cattle stocks on the Baltic island of Öland in southern Sweden. The scale dependency was evaluated by comparing three levels of spatial resolution of patches. Prevalence data were obtained from slaughtered animals. Our models predict that the prevalence of D. dendriticum increases in grazed areas with woody vegetation, whereas moist and wet areas decrease parasite prevalence. The predictive power of the statistical models increased with increasing level of patch resolution. Approximately 42% of the variation in parasite prevalence (angular transformation) was explained by the areal proportion of vegetation types (4th-root-transformed). Based on the results obtained, we believe that our model strategy provides a rational and systematic tool to identify habitats that carry risk for D. dendriticum infection of ruminants, and that it can be applied to other parasites with similar life cycles such as Fasciola hepatica.

Dicrocoelium dendriticum: a true infection?

Dicrocoelium dendriticum is a liver parasite of ruminants. Humans are occasionally infected by ingestion of intermediate hosts. We report a rare case of dicrocoeliasis in a 55-year-old woman who presented with eosinophilia and elevated bilirubin. Therapy with albendazole eradicated the parasite and normalized blood parameters.

[Prevalence of liver flukes in hair goats slaughtered in Hakkari (Yüksekova) Province]

The aim of this investigation was to determine the prevalence of distomatosis in 267 hair goats which were slaughtered in the slaughterhouses belonging to butchers located in Yüksekova district of Hakkari province. In the study, distomatosis were detected in 165 (61.80%) of the 267 hair goats. Distomatosis was found in 20/98 (20.41%) hair goats which were younger than one year old and in 145/169 (85.80%) which were older than one year. It was found that the species most often responsible were Fasciola hepatica (41.21%) and Dicrocoelium dendriticum (42.42%). Mixed infections (F. hepatica+D. dendriticum) were found only in hair goats older than one year (13.94 %). In this investigation, Fasciola gigantica was found to infect only the ones older than one year (2.76%).

Lipid peroxidation and antioxidant potential of sheep liver infected naturally with distomatosis

The aim of this study was to assess the effects of natural distomatosis infections on sheep liver malondialdehyde (MDA) concentration, activities of enzymatic antioxidants (glutathione peroxidase (GPx), superoxide dismutase (Cu, Zn-SOD), catalase (CAT)) and concentrations of non-enzymatic antioxidants (reduced glutathione (GSH), vitamin C, and beta-carotene). Eighteen Akkaraman sheep naturally infected with Fasciola sp and Dicrocoelium dentriticum (D. dentriticum) and ten healthy Akkaraman sheep were included in the study Liver samples for the analysis of MDA, GPx, Cu, Zn-SOD, CAT, GSH, vitamin C, and beta-carotene and blood samples for the measurement of alanine aminotransferase and aspartate aminotransferase were collected immediately after sheep in the two groups were slaughtered. The concentration of MDA and activity of GPx in the group with distomatosis were higher than in the control group (P < 0.001). However, the Cu, Zn-SOD, CAT activities and the GSH, vitamin C concentrations in the infected group were significantly lower than in the control group (P < 0.001). The serum beta-carotene was not found to be statistically different in the two groups (P > 0.05). ALT and AST serum activities of the group with distomatosis were significantly higher in comparison to the control group (P < 0.001). In this study it was demonstrated that lipid peroxidation increased and activities or/and concentrations of antioxidant compounds were significantly changed in the liver of sheep with distomatosis.

Characterization of the 28S and the second internal transcribed spacer of ribosomal DNA of Dicrocoelium dendriticum and Dicrocoelium hospes

Isolates of Dicrocoelium dendriticum (n=150) from sheep and cattle bred in southern Italy and isolates (n=5) of D. hospes from a Bos indicus from Senegal were characterized genetically. The 28S region and the second internal transcribed spacer (ITS-2) plus flanking 5.8S and 28S sequences (ITS-2+) of ribosomal DNA (rDNA) were amplified by polymerase chain reaction and sequenced from individual flukes. Regarding the 28S rDNA, sequences of 568 and 581 bp were obtained for D. dendriticum and D. hospes, respectively. No intraspecific variation was observed between the 28S rDNA of all the D. dendriticum specimens studied and the D. dendriticum 28S rDNA sequence present in GenBank. However, intraspecific variation was observed in the 28S rDNA of the D. hospes specimens compared to the sequence present in GenBank. Regarding the ITS2+ rDNA, sequences of 402 and 428 bp were obtained for D. dendriticum and D. hospes, respectively; both sequences were deposited in GenBank. Variations intra- and interpopulation were observed for D. dendriticum, whereas 100% identity was observed in all the ITS2+ sequences of D. hospes. With respect to the interspecific variations, the ITS-2+ of D. dendriticum and D. hospes differed in 33 positions. The findings of the present study showed an ITS2+ sequence variability (8.2-8.5%) between D. dendriticum and D. hospes, thus demonstrating the utility of this sequence to discriminate the two species.

EPIDEMIOLOGICAL CHARACTERISTICS OF AN INVADING PARASITE: DICROCOELIUM DENDRITICUM IN SYMPATRIC WAPITI AND BEEF CATTLE IN SOUTHERN ALBERTA, CANADA

Previous surveys of wild ungulates indicate that the liver fluke, Dicrocoelium dendriticum, was rare in the Cypress Hills area of southeastern Alberta. However, 41 of 59 wapiti (Cervus elaphus) sampled during the 2003 and 2004 hunting seasons from this region were infected, with 7 hosts containing >1,000 worms. Prevalence and mean intensity were similarly high in sympatric beef cattle and mule deer. Worm abundance in wapiti was age related, with calves containing significantly higher numbers of worms (mean +/- SD abundance = 825 +/- 1098) than adults (107 +/- 259). This pattern with host age was not evident in beef cattle, although the smaller sample sizes may be a contributing factor. These results indicate that D. dendriticum is now well established in Cypress Hills Park, circulating between at least 3 species of sympatric ungulates, including beef cattle.

Morphometry on Lancet Flukes Found in Japanese Sika Deer (Cervus nippon centralis) Captured in Iwate Prefecture, Japan

Thirty-six flukes were collected from the livers of wild deer (Cervus nippon centralis) captured in Iwate Prefecture, Japan, and were served for morphometry. The length and/or the width of the body, suckers, testes, ovary, vitelline glands, cirrus pouch and eggs in the uterus of the flukes were measured. The distance between anterior end of the body and position of the maximal body-width or upper end of the testes were also determined. A remarked morphological characteristic was that the right and left testes did not lie tandem but lined bilaterally. Also the position of the maximal body-width did not always locate in the posterior part of the body of the fluke. The property was in accordance with those for Dicrocoelium chinensis.

A retrospective survey of liver fluke disease in livestock based on abattoir data in Shiraz, south of Iran

Meat-inspection records in an abattoir located in the Fars province (southern part of Iran) from 20 March 1999 to 19 March 2004 were used to determine the prevalence and long-term trend of liver fluke disease in sheep, cattle and goats in the region. A total of 844,039 animals (cattle 131,716; sheep 577,090; goats 135,233) slaughtered in the 5-year period and overall 34,856 (4.1%) livers were condemned. Fasciolosis and dicrocoeliosis were responsible for 54 and 21% of total liver condemnations, respectively. The prevalence of liver condemnations due to fasciolosis was decreased from 3.89, 3.20 and 2.63% in 1999-2000 to 1.07, 0.59 and 0.24% in 2003-2004 for cattle, sheep and goats, respectively. The corresponding features for dicrocoeliosis were similar, declining from 1.47, 1.76 and 2.10% in 1999-2000 to 0.69, 0.34 and 0.25% in 2003-2004, respectively. Drought climatic conditions in conjunction with a greater awareness among farmers could be responsible factors.

An unusual case of biliary obstruction caused by Dicrocoelium dentriticum

Dicrocoelium dentriticum (D. dentriticum) is a liver fluke induced biliary obstruction. Infection usually occurs in herbivores such as sheep, goats and deer; human infection is very rarely encountered in clinical practice. We report on a 65-y-old female presenting with biliary obstruction caused by D. dentriticum. Following treatment with triclobendazole, her symptoms disappeared, and laboratory values returned to normal range within 6 months. Parasitosis is an important cause of biliary obstruction. We suggest that for patients presenting with biliary obstruction, D. dentriticum should be included in the differential diagnosis.

Herd-level seroprevalence of fasciolosis in cattle in north central Portugal

An epidemiological study of Fasciola hepatica in cattle was implemented in the north central region of Portugal. Both an enzyme-linked immunosorbent assay and an egg shedding quantification technique were used in the follow-up of seven herds. Two of these herds were negative and the other five were positive for F. hepatica. A herd cut-off of value of 0.425 optical density was calculated and herd sensitivity (HSe) and herd specificity (HSp) were defined. Three seroprevalence studies were also implemented in the region with stratification by county sub-regions for a period of 18 months. Overall mean herd prevalence in Vagos of 11, 23 and 48% was progressively found for the three studies, respectively.

Hepatic marker enzymes, biochemical parameters and pathological effects in lambs experimentally infected with Dicrocoelium dendriticum (Digenea)

Hepatic enzymes and biochemical parameter values were analysed in the sera of 32 lambs: 12 infected with 1,000 Dicrocoelium dendriticum metacercariae, 12 with 3,000 and eight controls. Blood samples were collected at intervals of 30 days from day 0 post-infection (p.i.). Half the lambs in each group were slaughtered on days 60 and 180 p.i, respectively. A histopathological and ultrastructural study was carried out on the liver, gall bladder and hepatic lymph nodes of all animals. A minute increase was detected in the bilirubin (7%) and albumin (3%) values in the infected lambs (with 30-2,063 worms) in comparison with those of the controls. The hepatic enzyme values did increase, above all aspartate aminotransferase (19%) and alanine aminotransferase (22%), mainly in the lambs tested with 3,000 metacercariae (38% and 48%, respectively). The increase was significant 60 days p.i. The severity of the lesions was closely associated with the parasite burden.

Paleoparasitological Analysis of Coprolites from K2, an Iron Age Archaeological Site in South Africa: The First Finding of Dicrocoelium Sp. Eggs

Until now, Dicrocoelium sp. eggs have only been recorded from European and 1 North American archaeological sites. We present evidence for the first record of Dicrocoelium sp. from an African archaeological site. A paleoparasitological study was conducted on 7 coprolite samples from K2, a Late Iron Age site on the farm Greefswald, in the Northern Province of South Africa. Standard parasitological analysis revealed the presence of Dicrocoelium sp. and Trichuris sp. eggs. Today, the parasite does not occur in this region. Trichurid eggs are a relatively common find in paleoparasitological analysis. The presence of Dicrocoelium sp. provides new clues about the antiquity of this parasite, as well as aspects of ancient environment, climate, and interactions among humans, animals, and parasites.

[Prevalence of Fasciola hepatica and Dicrocoelium dendriticum in the cow: inspection in an east Switzerland abattoir]

On the basis of meat inspection in an abattoir in the eastern part of Switzerland, the incidence of liverflukes in cattle was recorded weekly during one year. The prevalence was compared with surveys from the seventies and nineties. The average incidence of Dicrocoelium dendriticum infection did not change. Although the prevalence of Fasciola hepatica apparently slightly decreased, an actual decrease of liverflukes could not be demonstrated.

Human infection with Dicrocoelium dendriticum in Riyadh district (Saudi Arabia)

Dicrocoelium dendriticum (the lancet fluke) is less common liver parasite. Adults inhibit bile duct, while characteristic eggs pass in stools. During one academic year, a total of 1196 patients referred to Parasitology Laboratory from King Abdel Aziz University Hospitals, 121 patients were positive for D. dendriticum. The majority was Saudis, and only 32 of the 121 patients (26.4%) had true dicrocoeliosis, as detected by re-examination after three days of liver free diet. The other patients have false Dicrocoeliasis. The infection was influenced by the patients' behaviours. The Saudis consume more sheep meat during month (Du-Elheja) of Haj and Feast. Examination of the slaughtered sheep at the governmental slaughterhouses showed the majority of them have the liver infected (9-24%) with the lancet liver fluke. It is concluded that rate of infection proportionates with the rate of sheep infection and the consumption of infected livers. For proper estimation of human infection should be on diet free liver before examination.

A preliminary study on dicrocoeliasis in Egypt, with a general review

Dicrocoelium dendriticum (D. dendriticum) is a lancet-shape liver fluke that affects sheep and mammals including man. Human and animal infections have been world widely reported particularly in some of the Eastern Mediterranean sheep raising countries. Infection is acquired by eating the second intermediate host (17 species of ants) with raw fruits, vegetables, herbs or even with the drinking water. As for the first intermediate host, there is about 54 different species of land snails. In spite of the fact that both the first and second intermediate hosts of D. dendriticum are available in Egypt, data about human and animal dicrocoeliasis is lacking. This investigation is a preliminary study to report on the presence of D. dendriticum (in sheep, goats and man in North Sinai Governorate) in Egypt.

A review of dicrocoeliosis of ruminants including recent advances in the diagnosis and treatment

Despite its widespread presence among grazing ruminants, dicrocoeliosis, also known as "small liver fluke" disease, is poorly known and often underestimated by researchers and practitioners in many countries. This is primarily due to the multiple parasitic infections which affect ruminant livestock and mask the pathology of dicrocoeliosis, to the difficulties in diagnosing it with coprological techniques and, finally, to the few effective drugs found. Furthermore, the biological cycle of Dicrocoelium, which requires a snail and an ant as intermediate hosts, and the high number of ecological and epidemiological variables affecting the disease make it difficult to set up experimental designs to study dicrocoeliosis. In the past 50 years, many aspects of this disease have been broadly investigated (aetiology, life cycle, diffusion, epidemiology, pathogenesis and immunology) but its diagnosis and treatment still remain moot issues. Dicrocoeliosis often remains clinically undetected and its diagnosis is mostly based on adult dicrocoelia recovered in the liver post mortem or on egg detected at coprological examination. The prophylaxis of the small liver fluke has been difficult and unsatisfactory to date due to the complexity of its biological life cycle and epidemiology. Many anti-helminthic drugs are practically ineffective against dicrocoeliosis if used at the dosage recommended against other gastrointestinal helminths and lungworms. The most important aspects of the aetiology, biological cycle, spread, epidemiology and pathogenesis of dicrocoeliosis are reviewed and the recent advances in the diagnosis and treatment are focused on.

Abattoir Condemnation due to Parasitic Infections and its Economic Implications in the Region of Trikala, Greece

The prevalence of parasitic infections responsible for the condemnation of carcasses and viscera during meat inspection, and their economic implication, was estimated in a year long abattoir survey of 10 277 slaughtered farm animals in the region of Trikala, Greece. The organs examined for the presence of parasitic lesions during meat inspection were: liver and lungs of all animals, rumen of cattle, small intestine of lambs and kids, and muscles of cattle and swine. The parasitic lesions observed in the lungs of cattle, sheep and goats were caused only by hydatid cysts. No hydatid cysts were observed in the lungs of swine. The parasitic lesions observed in the liver of cattle, sheep and goats were as a result of hydatid cysts and flukes of Fasciola hepatica and Dicrocoelium dendriticum, while those of swine were due to milk spots only. Moniezia sp. proglottids were found in the small intestine of lambs only. The prevalence of parasites responsible for the condemnation of marketable organs was low (0.26%). Parasites were responsible for 22% of the total of condemned organs, and their annual cost was 99, 00 GDR (approximately 292 Euros). The parasites most contributing to marketable organ condemnation were hydatid cysts (26%) and D. dendriticum flukes (26%).

Morphologic and biochemical changes caused by experimentally induced dicroceliosis in hamsters (Mesocricetus auratus)

BACKGROUND AND PURPOSE

The aim of the study reported here was to investigate the pathomorphologic changes caused by experimentally induced dicroceliosis and their correlation with hepatobiliary function.

METHODS

Studies were carried out at days 80 and 120 after oral inoculation of hamsters with 40 metacercariae of Dicrocoelium dendriticum.

RESULTS

The parasite-induced pathologic changes were assessed by presence of fluke eggs in feces, increased plasma alanine transaminase and aspartate transaminase activities and morphologic alterations. Dicroceliosis was characterized by bile ductular proliferation and enlargement of the bile duct surface area caused by hyperplastic cholangitis in septal bile ducts. The liver from infected animals contained portal tracts infiltrated with small to moderate numbers of lymphocytes, macrophages, and eosinophils. Simultaneously, there was an increase in portal tract collagen that extended to the interlobular septa and caused pressure atrophy of the hepatic parenchyma. The concentration of thiobarbituric acid-reactive substances and the ratio of oxidized to reduced glutathione, measured as markers of oxidative stress, were significantly increased.

CONCLUSIONS

The presence of oxidative alterations could be related to the morphologic evidence of chronic inflammatory response as well as to liver cellular injury indicated by cellular swelling, and increased presence of peroxisomes and lysosomes.

Natural dicrocoeliasis in imported sheep, Jeddah, Saudi Arabia

Dicrocoelium dendriticum is a common liver fluke of sheep and other herbivorous animals. Examination of imported sheep showed 40% in Somalian sheep, 26% in Turkish and 2% in native breed sheep. The results were discussed with stress on epidemiology.

Epidemiology of parasitoses in dairy animals in the North West Humid Himalayan Region of India with particular reference to gastrointestinal nematodes

A systematic survey was conducted during two spells of 5 years each (1986-1990 and 1993-1997) to study the prevalence of parasitoses with particular reference to gastrointestinal (GI) nematodes and flukes in dairy animals (crossbred and native cattle, and buffaloes) belonging to 12 villages in the Kangra valley (Himachal Pradesh). Flukes (Fasciola, amphistomes and Dicrocoelium) and strongyles were the most important parasitic infections. Fasciola was endemic throughout the year, with a higher percentage infection in buffaloes than in cattle. Other fluke and nematode infections showed a seasonal pattern in prevalence, with a small peak in March April followed by a high peak in July September. The faecal egg counts (eggs per gram, epg) of flukes (Fasciola/amphistomes) ranged from 50 to 300 in cattle and 50 to 400 in buffaloes, with high loads during the rainy and post-rainy seasons. The GI nematode egg counts (excluding Toxocara) revealed a similar trend, with the overall monthly mean epg ranging from 85 to 1720 in cattle and 90 to 1625 in buffaloes, with a high peak during the months of July to September. On coproculture of positive samples, the nematode infections in order of prevalence were: Strongyloides, Trichostrongylus, Haemonchus, Oesophagostomum, Bunostomum and Mecistocirrus. The prevalence of most of the parasites was lower during the second 5-year period.

[Liver fluke infestation in New World camelids. Parasitology, pathology, clinical findings and therapy]

In Llamas and Alpacas infestation with Fasciola hepatica or Dicrocoelium dendriticum can cause liver damage, sometimes even with lethal outcome. Once infected South American Camelids (SACs) react more sensitively to these parasites than other domestic ruminants. We report here on the pathology, parasitology, clinics and therapy of this disease. Concerning Dicrocoelium dendriticum we describe own clinical results and therapeutic outcome in addition to the pathological investigation. According to anatomic corrosion casts, the bile ducts of SACs show more similarity with the equine bile system than with the bile system of domestic ruminants.

Evaluation of techniques for the enumeration of Dicrocoelium eggs in sheep faeces

To evaluate the accuracy of quantitative techniques for the enumeration of Dicrocoelium dendriticum eggs in faeces, eggs were added to fluke free sheep faeces to achieve densities of 25, 50, 100, 200, 400 or 800 eggs per gram (epg) (5 replicates per density). The faecal egg counts were determined by a modified McMaster method (WETZEL, 1951) utilizing solutions of ZnSO4 (sp. g. 1.3 and 1.45), K2CO3 (sp. g. 1.45) and HgI2/KI (sp. g. 1.44) for flotation or by a sedimentation technique (4 sedimentation processes of 45 min each). The influence of flotation time on egg counts was assessed by counting the eggs 3-5, 15-20, 30-35, 45-50 and 60-65 min after loading the McMaster chamber. The results were expressed as percentage rate of recovery. Significant best rate of recovery, 91.2 +/- 9.4%, was achieved using HgI2/KI solution for flotation and there was no significant influence of flotation time on the egg count. Utilizing ZnSO4 solutions and K2CO3 solution for flotation the rates of recovery for Dicrocoelium eggs were 9.0 +/- 7.1%, 26.7 +/- 24.9% and 13.0 +/- 11.6%, respectively, and a flotation time of more than 3-5 min did significantly increase the number of floated eggs. The rate of recovery for Dicrocoelium eggs using the sedimentation technique was 41.2 +/- 1.5%.

Characterization of adult Dicrocoelium dendriticum by isoelectric focusing

Water soluble extracts of 3131 adult specimens of Dicrocoelium dendriticum from cattle, sheep and goats, mainly from León province, were analysed by isoelectric focusing in thin-layer polyacrylamide gels. Activity of the following enzymes was studied: lactate dehydrogenase (LDH, EC 1.1.1.27), glucose phosphate isomerase (GPI, EC 5.3.1.9), phosphoglucomutase (PGM, EC 2.7.5.1), acid phosphatase (AcP, EC 3.1.3.2), alpha-glycerophosphate dehydrogenase (alpha-GPDH, EC 1.1.1.8), hydroxybutyrate dehydrogenase (HBDH, EC 1.1.1.30) and malate dehydrogenase (MDH, 1.1.1.37). Five distinct enzyme types were recognized for LDH (pH range 6.30-7.13), GPI (pH 6.13-6.80) and PGM (pH 6.20-6.60) whereas AcP showed three different patterns (pH 5.70-5.92). Weak and diffuse activity was detected for MDH (pH 4.8-6.2) and no activity was observed for alpha-GPDH and HBDH. In general, little phenotypic variation was observed between worms recovered from a single host, between those from hosts of the same species and between those from hosts of different species, although some enzyme types were found in some animals but not others. Nevertheless, it must be taken into account that most parasites came from sheep and also from a relatively small area in north-west Spain.

A DNA probe for the detection of Dicrocoelium dendriticum in ants of Formica spp. and Lasius spp

Repetitive DNA sequences present in the genome of Dicrocoelium dendriticum were identified by hybridization of genomic DNA that had been digested with different restriction enzymes with 32P-labeled genomic D. dendriticum DNA. DNA fragments containing repetitive sequences were isolated from PstI-digested D. dendriticum DNA and were subcloned into a plasmid vector. Plasmids containing repetitive sequences were identified by colony hybridization. One of these plasmids, designated Ddr-IV, was isolated and used as a probe in further studies. Ddr-IV is specific for D. dendriticum since it does not hybridize to DNA isolated from other trematodes. In addition, Ddr-IV was capable of detecting D. dendriticum metacercariae in ants (Formica cunicularia, F. rufibarbis, and Lasius sp.), which act as second intermediate hosts in the parasite's life cycle. Since metacercariae constitute the infectious stage of the parasite for grazing animals, Ddr-IV will provide a useful tool for epidemiology studies of dicrocoeliosis.

Prevalence of dicrocoeliosis in sheep and goats in Himachal Pradesh, India

A survey incorporating field and abattoir studies was carried out on the prevalence of Dicrocoelium dendriticum in sheep and goats in the Kangra valley of Himachal Pradesh (India). Coprological studies on these migratory animals revealed that 8.1% of sheep and 4.1% of goats were positive for dicrocoeliosis, with a mean number of eggs per gram of faeces (EPG) of 702.1 for sheep and 566.7 for goats. The necropsy liver examination of slaughtered animals revealed that 24.1% of sheep and 12.3% of goats were infected with D. dendriticum and they had mean fluke burdens of 247.2 (sheep) and 298.1 (goats). No significant differences in fluke burden, liver lesion score and EPG count were observed between sheep and goats. The seasonal distribution of dicrocoeliosis indicated a higher percentage of infection in autumn and winter as compared with spring and summer. The potential role of migratory sheep and goats in the epizootiology of dicrocoeliosis is discussed.

Comparative evaluation of agar gel precipitation, counterimmunoelectrophoresis and passive haemagglutination tests for the diagnosis of Dicrocoelium dendriticum infection in sheep and goats

The sensitivity and specificity of the agar gel precipitation test (AGPT), counter immunoelectrophoresis (CIEP) and passive haemagglutination test (PHT) were evaluated for the diagnosis of Dicrocoelium dendriticum infection in naturally infected sheep and goats. Two hundred and forty five sheep and goat sera samples were tested using phosphate buffered saline, pH 7.2 extracted adult fluke antigen. CIEP detected 69.8% of the infected animals and was found to be the most sensitive, followed by PHT which detected 50.0% of the infected sheep and goats. AGPT was found to be the least sensitive, detecting only 23.8% of the infected animals. The specificity of

[Dicrocoelium dendriticum egg in feces of 2 Somali boys in Denmark. Transitory elimination after arrival to Denmark]

A case of spurious infection with Dicrocoelium dendriticum in two Somali boys in Denmark, who had eaten sheep's liver, is described. The diagnosis was established by careful questioning regarding culinary habits.

Ultrastructural investigations on the vitellaria of the digenean Dicrocoelium dendriticum

The paired vitellaria of the parasitic plathelminth Dicrocoelium dendriticum are composed of numerous follicles each of which contains vitellocytes at different stages of maturation and is enveloped by a basal lamina-like structure and a cytoplasmic sheath. The differentiation process of vitellocytes has been subdivided into three stages on the basis of morphological and functional characteristics. Stage I vitellocytes have a high nucleo/cytoplasmic ratio and a poorly differentiated cytoplasm mainly packed with free ribosomes. Stage II vitellocytes differentiate and increase in volume. Extensive RER and small Golgi complex appear and produce vesicles with an electron-dense content which fuse and give rise to large multigranular inclusions. Stage III vitellocytes are about to enter the vitelloduct, their cytoplasm is almost completely filled with the multigranular inclusions whose content reacts positively to the test for polyphenols. The inclusions are therefore interpreted as egg-shell globules. Mature vitellocytes also contain a small number of lipid droplets which are sometimes surrounded by a few polysaccharide particles, but completely lack protein yolk globules. The role of vitellocytes of D. dendriticum in egg-shell formation and embryo nutrition is discussed.

Studies on the incidence and pathogenesis of Dicrocoelium dendriticum in slaughtered sheep in Riyadh abattoir, Saudi Arabia

The incidence of Dicrocoelium dendriticum in slaughtered sheep both local and imported was carried out in Al Riyadh abattoir. A percentage of 28 was found among condemned livers. The highest rate of Dicrocoelium infection was among Naheemi sheep imported from Turkey. Recommendations to control this parasitic disease are necessary since it is a modern dangerous zoonotic parasite.

Coprological study of the Dicrocoelium dendriticum (Digenea) egg elimination by cattle in highland areas in León Province, northwest Spain

Dicrocoelium dendriticum egg output in cattle from five locations of the Porma river basin (León Province, Northwest Spain) was studied at monthly intervals between March 1986 and March 1987. We found D. dendriticum eggs in 37.64% of the 1251 samples examined, and the number of eggs per gram (epg) ranged from 10 to 1000 (average, 41.65 +/- 2.73). The main egg-elimination period, for prevalence, was autumn-winter. The average epg values were quite similar during all months except March, when the maximum was detected. The infection prevalence increased in cattle aged up to 2 years and then a slight, gradual decrease was observed with increasing host age. The average epg values ranged from 40.08 +/- 3.24 to 48.33 +/- 12.42 in all age groups except the oldest animals, for which the figures were lower. The rate of egg elimination was higher in animals that came from locations situated at a greater altitude.

Percutaneous ultrasound-guided cholecystocentesis in cows

A method was developed for percutaneous ultrasound-guided cholecystocentesis in cattle. The procedure was performed on the right side in the 9th, 10th, or 11th intercostal space of 30 cows. Of the 30 cows, 20 were slaughtered 24 hours after cholecystocentesis and the remaining 10 cows were slaughtered after a 10-day observation period. Changes in the peritoneum and gallbladder wall, observed at slaughter, were minimal. During the 10-day observation period, general behavior, attitude, and appetite of the 10 cows were normal. A transient, slight increase in rectal temperature was observed in 6 cows at 4, 5, or 8 days after cholecystocentesis. Total and differential WBC counts and total protein and fibrinogen concentrations, determined daily, were all within normal ranges. Bile samples from 20 cows were examined microscopically and biochemically. Fasciola hepatica and Dicrocoelium dendriticum eggs were observed in bile from 7 and 12 cows, respectively. Fecal examination revealed F hepatica eggs in 4 cows; D dendriticum eggs were not identified in any of the fecal samples. In 1 cow, F hepatica eggs were observed in the feces, but not in the bile. Bile acids concentration in bile varied from 12.5 to 68.5 mmol/L (mean +/- SD, 45.3 +/- 3.05 mmol/L) and in serum from 3.8 to 281.0 mumol/L (41.6 +/- 17.24 mumol/L). Negative correlation was obtained between bile acids concentration in bile and that in serum (r = -0.60, P less than 0.01). It was concluded that percutaneous ultrasound-guided cholecystocentesis in cows is a safe procedure and that microscopic and biochemical examinations of obtained bile can be useful diagnostic aids.

Human dicrocoeliasis. Report on 208 cases from Saudi Arabia

In 3 years, Dicrocoelium dendriticum ova were detected in 208 patients at the Armed Forces Hospital, Riyadh, Saudi Arabia during 1984-1986. At least 7 of these patients had a true infection and at least 34 patients had spurious infection as they gave a history of eating raw liver. 23% of the 208 patients were under 14 years of age. The peak incidence was between October and November in each of the 3 years. 134 of these patients were symptomatic. 16 patients had disturbed liver functions and 13 had eosinophilia. 10 patients had gall bladder or biliary tree disease and in at least 2 of which it was due to D. dendriticum. Malabsorption occurred in one patient. Praziquantel was used in 9 patients and was successful in treating 4 of these patients.

Studies on the parasitic helminths of slaughtered animals in Iraq. I. Parasitic helminths of the liver of herbivores

The livers and lungs of 580 sheep, 160 goats, 418 cattle, 50 camels and 48 buffaloes slaughtered in Baghdad in April-July, 1981 were examined for helminth parasites; 14.3% of the sheep, 0.6% of the goats, 18.2% of the cattle, 72.0% of the camels and 8.3% of the buffaloes were infected with trematodes and cestodes. Dicrocoelium dendriticum is reported from the livers of sheep in Iraq for the first time.

[The occurrence of hepatic trematodes in sheep from Emilia-Romagna]

In the present investigations, 563 samples of ovine faeces from 32 flocks of Emilia-Romagna have been examined for the presence of hepatic trematodes eggs. All flocks proved positive for Dicrocoelium dendriticum and 16 for Fasciola hepatica; 511 (90,76%) out of 563 animals proved positive, with 507 (90,05%) for D. dendriticum and 50 (8,88%) for F. hepatica, 46 of these last ones were positive for both parasites.

[Dicrocoelium dendriticum in sheep in the Democratic Republic of Germany district of Frankfurt/Oder]

In the district of Frankfurt/Oder of the German Democratic Republic, faecal examinations of 143 sheep stocks revealed a 31.3 percent infection with Dicrocoelium dendriticum. In different territories of the district, the intensity of the infection with Dicrocoelium dendriticum varied remarkably. Detailed investigations demonstrated, that the parasite was limited to pastures with Brownearth soil. Routine examinations revealed the fact, that the egg-output of Dicrocoelium dendritcum was very variable during the pasture season. During the whole time of the examinations, the authors found eggs in the faeces of sheep belonging to Dicrocoelium dendriticun. In the German Democratic Republic, this helminth species is not restricted to hills with limestones. It occurs also in lowlands with small amounts of lime like the Brown-earth zones of the district Frankfurt/Oder.

[Simultaneous presence of a Cestode cysticercoid (Cyclophyllidae, Hymenolepididae) and a Trematode metacercaria (Dicrocoeliidae) in Oxydesmus granulosus Palisot de Beauvoir (Myriapoda, Diplopoda, Polydesmidae) from Dahomey]

We report observations of cysticercoids of Hymenolepis gilloni (Hunkeler, 1972), a flatworm parasite of five species of Crocidura in Africa. The cysticercoids are found up against the outside of the gut of Myriapode, Oxydesmus granulosus, from Porto Novo (Dahomey). We also found the metacercaria of a Trematode which is probably a Dicrocoeliidae.