Éva Fok

First autochthonous Dirofilaria immitis (Leidy, 1856) infection in a dog in Hungary

SummaryA 4 year-old, male Hungarian Vizsla dog which had never been abroad was referred with poor general condition, decrease in body weight, haematemesis and jaundice to the Central Clinic of Veterinary Science University, Budapest. After symptomatic treatment abdominal ultrasonography and diagnostic laparatomy were carried out. The dog was humanely euthanized two days later following owner’s consent because of sudden worsening of clinical conditions. Two adult heartworms (Dirofilaria immitis) were found in the right ventricle partially coiling around the tricuspid valve. PCR on blood was positive for both D. immitis and Dirofilaria repens while only D. repens microfilariae were found by modified Knott’s test and the serological test was negative for D. immitis antigens. This is the first, confirmed report of autochthonous canine heartworm infection in Hungary.

Screening blood-fed mosquitoes for the diagnosis of filarioid helminths and avian malaria.

BackgroundBoth Dirofilaria repens and recently D. immitis are known to be endemic in Hungary. As one of several recent cases, the fatal case of a dog infested with D. immitis in Szeged, Southern Hungary, received attention from the media. Hence it was decided to catch mosquitoes in the garden where the dog lived to screen for filarioid helminths and Plasmodium spp. using molecular tools.MethodsMosquitoes were caught in Szeged, in the garden where the infected dog was kept, in July 2013 with M-360 electric mosquito traps and were stored in ethanol until further procedure. Female mosquitoes were classified to genus level by morphology. Each mosquito was homogenized and analyzed for filarioid helminths and avian malaria using standardized PCR techniques. Positive mosquito samples were further identified to species level by comparing a section of the mitochondrial COI gene to GenBank® entries.ResultsIn this study, 267 blood-fed mosquitoes were caught in July 2013 in Szeged. Subsequent molecular screening revealed that not only D. immitis was present in the analyzed specimens but also DNA of D. repens, Setaria tundra and Plasmodium spp. was confirmed.ConclusionsThe analysis of blood-fed mosquitoes for the diagnosis of Dirofilaria spp. and other mosquito-borne pathogens seems to be an adequate technique to evaluate if filarioid helminths are present in a certain area. Usually only unfed female mosquitoes are analyzed for epidemiological studies. However, blood-fed mosquitoes can only be used for screening if a pathogen is present because the role of the mosquito as vector cannot be classified (blood of bitten host). Furthermore, Setaria tundra was confirmed for the first time in Hungary.

Sarcocystis-infection of cattle in Hungary

BackgroundReports on Sarcocystis-infection of cattle are outdated or lacking in many European countries, including those in the Central-Eastern part of the continent. Therefore, to assess the prevalence of Sarcocystis spp. among bovids in Hungary, a countrywide survey was initiated. In addition, fulminant deaths of four cattle, that showed clinical signs and post mortem lesions resembling acute sarcocystiosis (“Dalmeny disease”), were investigated.MethodsDuring the countrywide survey individual heart and oesophagus samples were collected at slaughterhouses from 151 beef cattle and from 15 buffalo, kept in 31 places of Hungary. Analysis for Sarcocystis spp. was carried out with conventional PCRs for the 18S rDNA gene and gel electrophoresis, followed by sequencing of 36 strongly positive samples. Mortality cases were evaluated by histological, molecular, bacteriological and virological analyses of samples from various organs.ResultsAmong slaughtered cattle the rate of Sarcocystis-infection was 66%. S. cruzi was identified as the most prevalent species in aurochs-like breed, and the zoonotic S. hominis in Hungarian grey cattle. Concerning the sudden deaths of cattle, Sarcocystis-infection could not be demonstrated in organs showing haemorrhages, but S. cruzi cysts were present in the muscles. In one case “S. sinensis” was molecularly identified in the blood (indicating sarcocystaemia). Results of analyses for bacterial/viral pathogens were negative.ConclusionsS. cruzi appears to be the most prevalent Sarcocystis sp. in cattle in Hungary, followed by the zoonotic S. hominis. However, the rate of infection with both species was shown to differ between cattle breeds. The suspected role of Sarcocystis spp. as causative agents of the fatal cases could not be confirmed.

Preliminary findings on the efficacy of selamectin in the treatment of dogs naturally infected with Dirofilaria repens

Subcutaneous dirofilariosis caused by Dirofilaria repens is common in dogs and it is an emerging helminthozoonosis in Europe, Asia, Africa and also in Hungary. Macrocyclic lactones are used for preventing the infection; however, their activity against the microfilariae and mature stages of this species is questionable. Selamectin is widely used for the prophylaxis of heartworm (D. immitis) infection. The objective of the present study was to test the microfilaricidal efficacy of the topical formulation of selamectin in dogs naturally infected with D. repens . A total of 78 Beagle dogs were examined for the presence of circulating microfilariae by Knotts test. Twenty-three of the microfilaraemic dogs were divided into four groups and included in the trial. The dogs received monthly or biweekly selamectin treatment and were subjected to monthly blood testing for a period of 252 or 336 days. At the end of the study, 65% of the dogs were not microfilaraemic and the rest had low number of microfilariae in their blood. These results indicate that chronic spot-on selamectin treatment may be a useful tool also in the control of canine subcutaneous dirofilariosis.

Prevalence of Setaria equina microfilaraemia in horses in Hungary.

Peripheral blood samples were collected randomly from 195 horses in various parts of Hungary, and the presence of microfilariae was evaluated by the Knott technique. On the basis of morphological identification 18 of the horses (9·2 per cent) were infected with Setaria equina, and the infection was confirmed in 10 animals by pcr and sequencing. The level of microfilaraemia was between 1 and 1138 larvae in 2 ml of blood. There was no correlation between the time of sampling or the sex of the animals (stallions versus mares) and the prevalence of infection, but the prevalence decreased with age. There was a significant association between the prevalence of microfilaraemia and the presence of still waters; positive samples were collected either in the region of Lake Balaton, the largest lake in the country, or at places with nearby ponds.

Toxoplasmosis in Tammar wallabies (Macropus eugenii) in the Budapest Zoo and Botanical Garden (2006-2010)

Smaller macropodid species (commonly referred to as wallabies) are extremely susceptible to toxoplasmosis: in most cases, infection with Toxoplasma gondii leads to death within a short time. Between June 2006 and July 2010, T. gondii was detected by immunohistochemical examination in six Tammar wallabies (Macropus eugenii) that died in the Budapest Zoo and Botanical Garden; in another four specimens histopathology revealed T. gondii-like organisms (which could not be differentiated from Neospora caninum solely by morphology), and in another 11 animals toxoplasmosis as the possible cause of death could not be excluded. The current zoo population of 12 Tammar wallabies was tested for T. gondii IgG antibodies by the modified agglutination test (MAT), with negative results. We suppose that most of the deaths were due to acute toxoplasmosis resulting from a recent infection.