A canine purgation study and risk factor analysis for echinococcosis in a high endemic region of the Tibetan plateau

The Tibetan plateau of western China has been shown to have a very high prevalence of human cystic echinococcosis (CE) caused by Echinococcus granulosus and human alveolar echinococcosis (AE) caused by Echinococcus multilocularis. The domestic dog is suspected to be the primary definitive host for the transmission of both E. granulosus and E. multilocularis to humans in this locality. A purgation study of 371 dogs in Shiqu County, Sichuan Province during 2002-2003 resulted in an E. multilocularis prevalence of 12% and an E. granulosus prevalence of 8%. These crude prevalences were then adjusted, based on the known sensitivity of arecoline purgation for the detection of E. granulosus and a suggested sensitivity for the detection of E. multilocularis. In addition, it was assumed that some immature parasites of either species could be misidentified morphologically and wrongly assigned. This resulted in credible true prevalence intervals of between 13-33% for E. multilocularis and 8-19% for E. granulosus. Prevalences of other intestinal helminthes found on purgation were: Taenia spp. 31%, Dipylidium caninum 1%, and ascarids 8%. Risk factors associated with the acquisition of canine echinococcosis were evaluated based on responses to a questionnaire administered to dog owners. Male dogs were more likely to be infected with Echinococcus spp. than female dogs (P<0.05) and dogs allowed to roam were more likely to be infected with E. multilocularis (P<0.05).     

Detection of Echinococcus multilocularis in wild boars in France using PCR techniques against larval form

Recently, new data have been collected on the distribution and ecology of Echinococcus multilocularis in European countries. Different ungulates species such as pig, goat, sheep, cattle and horse are known to host incomplete development of larval E. multilocularis. We report a case of E. multilocularis portage in two wild boars from a high endemic area in France (Department of Jura). Histological examination was performed and the DNA was isolated from hepatic lesions then amplified by using three PCR methods in two distinct institutes. Molecular characterisation of PCR products revealed 99% nucleotide sequence homology with the specific sequence of the U1 sn RNA gene of E. multilocularis, 99 and 99.9% nucleotide sequence homology with the specific sequence of the cytochrome oxydase gene of Echinococcus genus and 99.9% nucleotide sequence homology with a genomic DNA sequence of Echinococcus genus for the first and the second wild boar, respectively.     

Echinococcus multilocularis infections in domestic dogs and cats from Germany and other European countries

A cross-sectional survey was conducted to estimate the prevalence of Echinococcus multilocularis and E. granulosus infections in domestic dogs and cats from Germany and other European countries. Faecal samples of 21,588 dogs and 10,650 cats routinely submitted to a private veterinary laboratory between June 2004 and June 2005 were examined using the ZnSO(4)-NaCl flotation method. Taeniid eggs were detected in 54 (0.25%) and 37 (0.34%) of the canine and feline faecal samples, respectively. Taeniid eggs were separated and subjected to a DNA preparation and a modified two-step PCR for the detection of Echinococcus spp. based on mitochondrial 12S rRNA genes. PCR products from Echinococcus-negative but cestode-positive reactions were cloned and sequenced to determine the Taenia species. E. multilocularis DNA was specifically amplified in 43 (0.24%) and 25 (0.23%) of the samples from dogs and cats, respectively. E. granulosus DNA was not detected in any sample, while, E. multilocularis-positive samples were detected in dogs from Germany only, those of cats originated from Germany, Denmark and The Netherlands. The prevalence of E. multilocularis egg-positive canine samples was significantly higher in southern (0.35%) than in northern Germany (0.13%). In contrast, no significant regional difference was observed in cats from Germany. Taeniid eggs from Echinococcus-negative samples and from a few samples with macroscopically detected Taenia sp. proglottids were identified as eggs of T. crassiceps (n=8), T. martis, T. serialis, T. polyacantha, T. taeniaeformis and T. pisiformis in dogs (n=1 of each) and T. taeniaeformis (n=11) in cats. The spectrum of cestodes detected in domestic dogs and cats indicate the consumption of small rodents as infection source. The high proportion of E. multilocularis-positive samples, suggest domestic dogs and cats as a possible source of E. multilocularis infection for humans.     

Survey for Trichinella spp. in red foxes (Vulpes vulpes) in Belgium.

Concurrently with a survey for Echinococcus multilocularis in the red fox (Vulpes vulpes) in Flanders, northern Belgium, serological and parasitological analyses for Trichinella spp. were carried out from 1996 to 1999. Muscle samples from foxes in Wallonia, southern Belgium, were obtained during a survey for rabies and alveolar echinococcosis from 1998 to 2000.In muscle samples from tongue, diaphragm, hindlegs and tail of 179 Flemish foxes no larvae were found by trichinoscopy. Serum and muscle juice of, respectively 176 and 26 animals were examined using an ELISA for the detection of antibodies against excretory-secretory (ES) antigen. There were eight (4.5%) positive sera, but no positive muscle juice samples.All muscle samples from 639 foxes in Wallonia proved to be negative for larvae in artificial digestion. Serum and muscle juice of 130 and 478 foxes, respectively were examined in ES-ELISA. There were 61 (46.9%) positive sera and 90 (18.8%) positive muscle juice samples. A comparison between 88 serum and muscle juice samples of the same foxes showed that only half of the serum-positive animals were detected using muscle juice. However, for establishing the true meaning of these results, a more profound epidemiological study on the vulpine population in Belgium is necessary.     

Survey to determine the seroprevalence of Toxoplasma gondii infection in British sheep flocks

A serological survey of Toxoplasma gondii infection in adult breeding sheep in Great Britain was conducted using surplus sera taken during a seroprevalence study of Brucella melitensis in 2009. Of the 3539 sera collected from 227 flocks, 2619 (74 per cent) were found to be positive for T gondii specific antibody when tested using latex agglutination. Multilevel logistic modelling suggested that the likelihood of infection increased with age and this effect appeared to be amplified in animals vaccinated against T gondii. The model also indicated that the odds of sheep being seropositive were increased on premises where cattle were also kept. These results suggest a high level of Toxoplasma infection in breeding sheep in Great Britain and provide further evidence to suggest that postnatal infection is more common than congenital infection in sheep.     

Farmed wild boars exposed to Toxoplasma gondii and Trichinella spp

The meat of wild boar (Sus scrofa L.) can be a source of human infections with zoonotic parasites Toxoplasma gondii and Trichinella spp. We screened 197 wild boar sera collected at slaughter from 25 Finnish farms in 2007-2008 for serological evidence of infections with these parasites. Using a commercial direct agglutination test at a serum dilution of 1:40, T. gondii-specific IgG antibodies were detected in 65 (33.0%) samples, on 14 (56.0%) farms. Females, animals older than 24 months, animals of small herds, and animals originating from south-western parts of Finland were more often T. gondii-seropositive than were males, younger animals, animals of larger herds, and animals originating from the north and east, respectively. Four (2.0%) of the sera, originating from three (12.0%) farms, tested Trichinella-seropositive with an in-house ELISA and a conservative cut-off for seropositivity. One farm had both T. gondii- and Trichinella-seropositive animals. Taken together, an infection source had been present on 16 (64.0%) farms, and 69 (35.0%) of the 197 farmed wild boars intended for human consumption had specific serological evidence of exposure to a zoonotic parasite.     

Parasite fauna of red foxes in Berlin (West)

The infestation with ecto- and endoparasites of red foxes in Berlin (West) was investigated. As shown by post mortems of 100 animals (47 males and 53 females), none of them was found to be free of parasites. With regard to ectoparasites, 3 species of ixodes ticks, 7 flea species, one species of biting lice and mite species were demonstrated. The sarcoptic mange is often inducing the death of the foxes and is considered to be a limiting factor of the population increment. Concerning endoparasites, cestodes (6 species), trematodes (7 species), nematodes (10 species) and 3 coccidian species were found. The infestation rate with different species of hook worms, ascarids and mesocestoides was remarkably high. However, none of the foxes were infected with Trichinella spiralis or Echinococcus multilocularis. As shown by ELISA, in 15% of foxes antibodies against Borrelia burgdorferi were found. Therefore, the red fox must be considered as a reservoir host for Lyme-borreliosis.     

Morphological and molecular characteristics of Echinococcus multilocularis and Echinococcus granulosus mixed infection in a dog from Xinjiang, China

The Xinjiang plateau of western China has been shown to have a high prevalence for human cystic echinococcosis (CE) caused by Echinococcus granulosus, and human alveolar echinococcosis (AE) caused by Echinococcus multilocularis. The domestic dog is suspected to be the primary definitive host for the transmission of both E. granulosus and E. multilocularis to humans in this locality. Seventeen of 30 stray dogs from Hejing County of Xinjiang were found positive for E. granulosus post mortem, and one double infection was suspected. Worm samples were collected, dyed by carmine, and observed microscopically. Carmine staining examination clearly revealed the differences in number of proglottids and appearance of uterine branches and lateral genital pore for those two species of Echinococcus. Furthermore, gene target DNA fragments were amplified for formal identification of the two parasite species, based on 12s rRNA mitochondrial gene. The PCR products were purified and sequenced. Compared with NCBI GenBank, the DNA sequences demonstrated 100% identity with E. granulosus (sheep strain, G1 genotype) and E. multilocularis.     

The helminth fauna of red foxes (Vulpes vulpes Linnaeus 1758) in north Hesse and east Westphalia. 1. Cestodes]

Between November 1989 and June 1990 a total number of 397 foxes were examined for the presence of cestodes. The animals came from the districts of Arnsberg, Detmold and Kassel. In 16.4% of the foxes infections with Echinococcus multilocularis were found, in 28.5% Taenia crassiceps, in 14.4% Taenia polyacantha, in 4.3% Mesocestoides spp., in 3.3% Multiceps multiceps, in 2.5% Hydatigera taeniaeformis, in 0.8% Taenia hydatigena and in 0.3% Taenia martis. Infections with Echinococcus multilocularis very often showed high worm numbers of more than 1000 per fox. The number of worms for the other cestodes mostly varied between one and ten specimen per animal.     

Detection of Echinococcus multilocularis in foxes in The Netherlands

Echinococcus multilocularis was demonstrated in 5 out of 272 foxes in The Netherlands close to the border with Germany and Belgium. Besides microscopic examination of mucosal scrapings, two different PCR assays were used based on the detection of E. multilocularis DNA in colon content. Two distinct areas in The Netherlands were positive for E. multilocularis. Two positive foxes were found in the northern province of Groningen and three positive foxes were found in the southern province of Limburg. Both PCR assays detected more positive foxes compared to microscopic examination of the intestinal content. This is the first report of E. multilocularis in foxes occurring in The Netherlands.     

Control of Echinococcus multilocularis in Central Europe-- possibilities and limitations

Human alveolar echinococcosis is a life-threatening parasitic zoonosis which occurs in rare cases in Central Europe. It is caused by the larval stage of Echinococcus multilocularis. In this publication, strategies for the control of parasites of the genus Echinococcus are reviewed and discussed with regard to their applicability to E. multilocularis on the background of the epidemiological situation in Central Europe. First results of field studies are presented in which strategies based on the application of praziquantel-containing baits to foxes have been tried. Requirements concerning the surveillance of control measures are demonstrated and the limitations of the imaginable control strategies discussed.     

Prevalence of Echinococcus multilocularis in the red fox (Vulpes vulpes) in southern Belgium

Between June 1998 and February 2002, 709 red foxes killed in Wallonia (south of Belgium) were available for parasitological examination of the gut. The identification of Echinococcus multilocularis was based on morphological data. E. multilocularis adults were observed in 20.2% of the animals. The analysis of data revealed marked differences between the geological areas of Wallonia; the highest prevalence (33%) was found in the Ardenne and the lowest (0%) on the Plateau de Herve. Host gender and the collection season had no effect on the prevalence. However, the latter was significantly higher in juveniles (<8 months of age). The geographical distribution of E. multilocularis in Belgium is much wider than originally thought.     

The first detection of Echinococcus multilocularis in slaughtered pigs in Poland

Alveolar echinococcosis is a serious zoonosis caused by the larval stage of Echinococcus multilocularis. Pigs, as humans, can play the role of non-specific intermediate hosts of this parasite. Detection of E. multilocularis in swine can be taken as an indicator of infection risk for humans. This paper presents the first cases where E. multilocularis larval forms have been detected in pigs in Poland. A total of 256 pig livers with different lesions were collected from slaughterhouses in southern Poland and examined by nested PCR method. Three of them were identified as E. multilocularis positive. They contained noticeable spherical nodular whitish forms on the surface of the liver, recessed partially into the liver tissue. In two cases only single lesions (3mm and 6mm in diameter) were found, while in one case numerous (eight) lesions (2mm in diameter) were found. PCR E. multilocularis identification was confirmed by sequencing and comparison with the GenBank database.     

Field evaluation of an intravital diagnostic test of Echinococcus multilocularis infection in red foxes

Echinococcus multilocularis parasitizes the small intestine of red foxes (Vulpes vulpes) and other carnivores, and has a wide distribution throughout the northern hemisphere. This cestode is the causative agent of human alveolar echinococcosis, a life-threatening helminth zoonosis. In 2000-2002, 2130 red foxes were examined for its presence in Slovakia, with a total prevalence of 30.7%. The data on occurrence were obtained by the combination of necropsy of small intestines from red foxes and coproantigen detection in faecal samples. The correlation between the number of detected specimens and the value of optical density of copro-ELISA test was found. When worm burdens were low (1-25 specimens) the sensitivity of the method was 31.3+/-8.64%, when worm burdens were >50 specimens, 81.8+/-0.66%, and with high worm burdens (>1000 specimens) the sensitivity reached 100+/-0.34%. E. multilocularis presence was detected using the nested PCR method from the eggs in the faecal samples with a 100% specificity. In epidemiological surveys of this zoonosis, it is of crucial importance to detect animals with a high level of infection, which are responsible for the bulk of environmental contamination. The advantage of copro-ELISA test lies in allowing the intravital diagnostics to be employed within the epidemiological survey of E. multilocularis occurrence in the protected and urban areas.     

The first finding of Echinococcus multilocularis in dogs in Slovakia: an emerging risk for spreading of infection

Alveolar echinococcosis, caused by the metacestode Echinococcus multilocularis, is a zoonosis of public health significance. Apart from red foxes, other carnivore species can also serve as definitive hosts of this parasite. This study aimed to determine the occurrence of E. multilocularis in dogs in the Slovak Republic and identify risk factors for acquiring the infection. Out of 289 dogs examined, E. multilocularis was detected in eight samples (2.8%). Positive results were observed in shepherd dogs (12.5%), guard dogs (7.1%), hunting dogs (2.4%) and in one dog with unknown usage (2.5%). Catching rodents and feeding with raw viscera were confirmed to be the most important risk factors for E. multilocularis infection. On the contrary, the way of dog use, frequency of going to the rural areas, the age and gender of animals seem not to be risk factors for infection. No significant association was observed between the positivity of dogs coming from high endemic or non-endemic regions. This is the first report of E. multilocularis in dogs in the Slovak Republic that confirms substantial contribution of dogs to the transmission of the tapeworm in this territory and urges the necessity of prophylactic measures for dog owners.     

Echinococcus multilocularis (Cestoda,Taeniidae) in Red foxes (Vulpes vulpes) in northern Belgium

The first record of the tapeworm Echinococcus multilocularis (Cestoda, Taeniidae) in Red foxes (Vulpes vulpes) in northern Belgium is described. Between 1996 and 1999, 237 dead foxes were examined for the presence of this tapeworm using the intestinal scraping technique. Four foxes (1.7%) were found to be infected with E. multilocularis and showed medium to very high parasitic burdens. Three infected foxes originated from the south of the study area and the fourth animal came from the north of the study area near the border with The Netherlands. These findings are discussed in relation to the high endemicity of E. multilocularis in southern Belgium and to the increased distribution of the Red fox (V. vulpes) in northern Belgium during the last two decades.     

Helminth findings in indigenous raccoon dogs Nyctereutes procyonoides (Gray, 1843)

Internal organs of 74 racoon dogs originating from the eastern districts of the Federal Land Brandenburg were subjected to a complete helminthological dissection. In addition, samples of diaphragma muscles from 46 further animals were examined for Trichinella larvae. Altogether 3 trematode- (Alaria alata, Isthmiophora melis, Metorchis bilis), 3 cestode- (Mesocestoides sp., Echinococcus multilocularis, Taenia polyacantha) and 7 nematode species (Capillaria aerophila, C. plica, Trichinella spiralis, Uncinaria stenocephala, Molineus patens, Crenosoma vulpis, Toxocara canis) could be identified. Thereby, the racoon dog has a comparable helminth spectrum as well known in red foxes. Differences in the frequency of the occurrence of helminths in both hosts can be explained by different food preferences.     

First report of a Trichinella papuae infection in a wild pig (Sus scrofa) from an Australian island in the Torres Strait region

Multiple Trichinella species are reported from the Australasian region although mainland Australia has never confirmed an indigenous case of Trichinella infection in humans or animals. Wildlife surveys in high-risk regions are essential to truly determine the presence or absence of Trichinella, but in mainland Australia are largely lacking. In this study, a survey was conducted in wild pigs from mainland Australia's Cape York Peninsula and Torres Strait region for the presence of Trichinella, given the proximity of a Trichinella papuae reservoir in nearby PNG. We report the detection of a Trichinella infection in a pig from an Australian island in the Torres Strait, a narrow waterway that separates the islands of New Guinea and continental Australia. The larvae were characterised as T. papuae (Kikori strain) by PCR and sequence analysis. No Trichinella parasites were found in any pigs from the Cape York Peninsula. These results highlight the link the Torres Strait may play in providing a passage for introduction of Trichinella parasites from the Australasian region to the Australian mainland.     

Echinococcosis--an international public health challenge

This review aims to summarise some of the recent studies that have been undertaken on parasites of the genus Echinococcus and the diseases which they cause. Although the adult parasite, which inhabits the intestine of various carnivore species is not pathogenic, the larval or metacestode stages can be highly pathogenic, causing economic losses to livestock and various forms of echinococcosis in humans, some of which have a high fatality rate. There is growing evidence that there are at least 5 species of Echinococcus rather than the generally accepted 4 species. Within these species there are a number of genotypes or strains. This can have implications for surveillance and control. In some wealthy countries, cystic echinococcosis caused by Echinococcus granulosus has been successfully controlled or indeed eradicated. However, in most parts of the world it remains a serious threat to human health. In the former Soviet Union, the disease has rapidly increased in incidence after the end of communist administration. Human alveolar echinococcosis, caused by Echinococcus multilocularis, is more sporadic. However, in some Chinese communities there is a disturbingly high human prevalence and in Europe there has been an increase in the detection rate of E. multilocularis in animals in the last 10 years. Echinococcosis can present diagnostic challenges, particularly in the definitive host in areas of low endemicity. Much of the recent work relating to the use of coproantigen and PCR to overcome these difficulties is summarized. New ideas for controlling the parasite are becoming available and these include both the use of vaccination and the application of mathematical models to determine the most cost effective means of control. Effective measures that are affordable are vital if the parasite is to be controlled in poor countries.     

Echinococcus multilocularis and Toxocara canis in urban red foxes (Vulpes vulpes) in Brussels, Belgium

During the last decades, European red foxes (Vulpes vulpes) have been implicated in the transmission of several viral or parasitic pathogenic agents to domestic animals and humans. In urban areas, risks of zoonoses transmission are likely to increase as a result of a higher rate of intra- and inter-species contacts. Foxes occur on 35% of the Brussels-Capital Region area and local densities reach up to 4 family groups per square kilometre. According to the directive 2003/99/ECC, a first survey for the presence in foxes of Echinococcus multilocularis and Toxocara canis was conducted in Brussels from 2001 to 2004. None of 160 foxes were found to be infected with E. multilocularis and 24 of 134 foxes were found to be infected with T. canis. Considering numbers of examined foxes, the sensitivity and the specificity of tests used for diagnosis, the 95% credibility intervals for the true prevalence of E. multilocularis and T. canis were estimated in a Bayesian framework to be 0 to 1.87% (median value of 0%) and 12.7 to 26% (median value of 18.7%), respectively. For T. canis, a significantly higher risk to be a carrier occurs in cubs and a significantly lower risk in adults.