Echinococcosis in Dogs in the Czech Republic

Svobodová V. , B. Lenská: Echinococcosis in Dogs in the Czech Republic. Acta Vet. Brno 2002, 71: 347-350. In central Europe, foxes are principal definitive hosts of Echinococcus multilocularis. However, dogs may become definitive hosts too, and due to close contact with humans they may be the source of infection. We examined samples of dog faeces from the areas with high density of red foxes. The dogs were rigorously selected on the basis of specific individual history confirming predator habits and a possibility of free movement allowing the dogs to hunt for rodents. Samples of dog faeces were examined by ELISA detecting specific coproantigens Echinococcus spp. (CHEKIT – Echinotest, Bommeli, Switzerland). A total of 186 samples of dog faeces were examined with 15 positive cases detected (8.1%). Echinococcus multilocularis, coproantigens, ELISA, zoonosis, prevalence Parasitic diseases with zoonotic potential present a significant health problem worldwide. Echinococcus multilocularis, a small tapeworm of Taeniidae family, also belongs among zoonotic helminths. Its occurrence is especially linked to the fox as the definitive host. However, dogs and cats may become definitive hosts as well. In particular the animals that may hunt murids and that live in close contact with humans present a considerable risk. Such animals may also become source of the disease for humans. In the conditions of central Europe red fox (Vulpes vulpes) is the main definitive host of this parasite (Thompson and Eckert 1983; Dubinsk ̆ et al. 1999). Other definitive hosts may include the dog (Canis familiaris) (Deplazes et al. 1999) and the cat (Felis catus f. domestica) (Deblock et al. 1989; Petavy et al. 1988). Small rodents are becoming intermediate hosts. On the territory of the Czech Republic, they are represented in particular by common vole (Microtus arvalis) (Koláfiová 1999). The eggs of E. multilocularis may cause alveolar echinococcosis in humans, which is a dangerous zoonosis. The prevalence of alveolar echinococcosis in the endemic areas of central Europe ranges between 0.03 and 1.2 per 100,000 inhabitants (Eckert and Deplazes 1999). The objective of the present work was to establish the prevalence of E. multilocularis in dogs that live in and move around the areas with dense population of red foxes. Materials and Methods During the period of 2000 to 2001 samples of faeces were collected from dogs especially from the areas where the occurrence of E. multilocularis in red foxes was reported earlier (Pavlásek 1998; Mart ínek et al. 2001) or where it was indicated by the data provided by district offices of the State Veterinary Administration. The dogs were selected for the examination strictly on the basis of specific individual history confirming predator habits and a possibility to move around freely and to hunt for rodents. The numbers of samples of dog faeces from different localities with confirmed prevalence of E. multilocularis were as follows: 44 samples from a locality with 63.3% prevalence, 52 samples from another locality also with 63.3% prevalence, 4 samples from a locality with 6.6% prevalence, 6 and 39 samples from two distant localities with equally 28.6% prevalence. Samples were also taken from two localities where the occurrence in red foxes had not been confirmed (24 and 5 samples) and from one locality where no examination in red foxes had been carried out (12 samples). ACTA VET. BRNO 2002, 71: 347–350 Address for correspondence: Doc. MVDr. Vlasta Svobodová, CSc. Department of Parasitology, Faculty of Veterinary Medicine University of Veterinary and Pharmaceutical Sciences Brno Palackého 1-3, 612 42 Brno, Czech Republic Phone: + 420 5 4156 2265 Fax: + 420 5 4924 8841 E-mail: svobodovav@vfu.cz http://www.vfu.cz/acta-vet/actavet.htm The samples of dog faeces were stored at –18 °C and –80 °C until tested. One g of every sample was used for investigation. Samples of dog faeces were examined by ELISA for the detection of specific coproantigens of Echinococcus spp. (CHEKIT – Echinotest, Bommeli, Switzerland).

Parasitic diseases with zoonotic potential present a significant health problem worldwide.Echinococcus multilocularis, a small tapeworm of Taeniidae family, also belongs among zoonotic helminths.Its occurrence is especially linked to the fox as the definitive host.However, dogs and cats may become definitive hosts as well.In particular the animals that may hunt murids and that live in close contact with humans present a considerable risk.Such animals may also become source of the disease for humans.
In the conditions of central Europe red fox (Vulpes vulpes) is the main definitive host of this parasite (Thompson and Eckert 1983;Dubinsk˘et al. 1999).Other definitive hosts may include the dog (Canis familiaris) (Deplazes et al. 1999) and the cat (Felis catus f. domestica) (Deblock et al. 1989;Petavy et al. 1988).Small rodents are becoming intermediate hosts.On the territory of the Czech Republic, they are represented in particular by common vole (Microtus arvalis) (Koláfiová 1999).The eggs of E. multilocularis may cause alveolar echinococcosis in humans, which is a dangerous zoonosis.The prevalence of alveolar echinococcosis in the endemic areas of central Europe ranges between 0.03 and 1.2 per 100,000 inhabitants (Eckert and Deplazes 1999).
The objective of the present work was to establish the prevalence of E. multilocularis in dogs that live in and move around the areas with dense population of red foxes.

Materials and Methods
During the period of 2000 to 2001 samples of faeces were collected from dogs especially from the areas where the occurrence of E. multilocularis in red foxes was reported earlier (Pavlásek 1998;Martínek et al. 2001) or where it was indicated by the data provided by district offices of the State Veterinary Administration.The dogs were selected for the examination strictly on the basis of specific individual history confirming predator habits and a possibility to move around freely and to hunt for rodents.The numbers of samples of dog faeces from different localities with confirmed prevalence of E. multilocularis were as follows: 44 samples from a locality with 63.3% prevalence, 52 samples from another locality also with 63.3% prevalence, 4 samples from a locality with 6.6% prevalence, 6 and 39 samples from two distant localities with equally 28.6% prevalence.Samples were also taken from two localities where the occurrence in red foxes had not been confirmed (24 and 5 samples) and from one locality where no examination in red foxes had been carried out (12 samples).
The samples of dog faeces were stored at -18 °C and -80 °C until tested.One g of every sample was used for investigation.Samples of dog faeces were examined by ELISA for the detection of specific coproantigens of Echinococcus spp.(CHEKIT -Echinotest, Bommeli, Switzerland).
The summary of the results of examinations in dogs with breakdown by different areas with various levels of E. multilocularis prevalence in red foxes is presented in Table 1.Topography of different localities with confirmed echinococcosis in red foxes and dogs is depicted in Fig. 1.

Discussion
The overview of epidemiological situation in the Czech Republic was prepared by Koláfiová (1999).The occurrence is known in particular in foxes as the principal definitive hosts of Echinococcus multilocularis.Average prevalence was determined at 19.7% on the basis of monitoring during the period of 1994-1999, when intestines of red foxes which had been shot and found negative for rabies were examined (Pavlásek 1998).In some localities, especially in southern Bohemia, much higher values of prevalence at 70.6% (Pavlásek 1998) and 63.3% (Martínek et al. 2001) were found.Dogs and cats were confirmed as facultative definitive hosts by âada et al. (1999), who diagnosed post mortem the infection in a kitten, and by Martínek et al. (1999), who demonstrated presence of E. multilocularis in one case (1.8%) out of 55 samples of dog faeces collected on the streets of a small village in southern Bohemia.
There are not much data available on the occurrence of echinococcosis in dogs, because the post mortem diagnosis, which is normally used in red foxes, cannot be applied in dogs in large scale.Therefore mostly intravital methods are used.Average prevalence detected in our group of dogs was 8.1%.Positive samples of dog faeces originated also from the localities, where no occurrence of E. multilocularis was confirmed during recent years.It can be expected that at the level of 12.5% of positive samples of dog faeces the infection in red foxes does not occur at present.The prevalence of echinococcosis in dogs in the Czech Republic seems to be at a higher level, because for instance in Switzerland coproantigens were detected by ELISA in dogs in 0.3% only (Deplazes et al. 1999).Higher values of prevalence, diagnosed in dogs in the Czech Republic, correspond to our strategy of sampling, since the animals originated from the areas where the density of red foxes was high.Moreover, the owners reported that the animals selected had a possibility to move freely and to hunt for rodents.A similar situation with higher occurrence of echinococcosis in dogs in an endemic locality in Switzerland was described by Deplazes et al. (1998), who detected coproantigens in 9% of dogs on farms.Although the statement of positive detection in the areas where only low numbers of samples were obtained, may not be completely objective, it certainly shows that echinococcosis is not rare in the given locality.If the group of dogs sampled had been randomly selected from different parts of the country including large cities, the number of positive cases would be probably lower.
The detection of coproantigens specific for Echinococcus spp.by ELISA is genusspecific.However, on the basis of epidemiological situation in the Czech Republic and with regard to characteristic features of the group of dogs selected we assume that the agent was mainly Echinococcus multilocularis.Compared with SCT (Intestinal Sedimentation and Counting Technique, Rausch et al. 1990), the method used has a sensitivity of 80% and a specificity of 95-99% (Deplazes and Eckert 1996).Therefore we continue to store positive samples for PCR examination for the purpose of final diagnosis.
Although the occurrence of E. multilocularis in the definite hosts is not rare at all, the disease in humans develops only seldom (Kreidl et al. 1998;Auer and Aspöck 2001).A single case of alveolar echinococcosis was reported in humans in the Czech Republic (•lais et al. 1979).Nevertheless the danger of infection must be prevented.The dogs that may be exposed should be dewormed on a regular basis every three months with praziquantel or epsiprantel (Deplazes and Eckert 2001).

Table 1
Comparison of the values of echinococcosis prevalence in red foxes and dogs