Sessions

Canine circovirus (CanineCV) belongs to the family Circoviridae, genus Circovirus. Circoviruses are globally widespread pathogens with a wide host range. It includes relevant pathogens like porcine circoviruses 1-4 (PCV-1 to PCV-4), of which PCV-2 is the causative agent of postweaning multisystemic wasting syndrome (PMWS), as well as the Beak and feather disease virus (BFDV) in psittacine. While the role of these pathogens is well described in veterinary practice, canine circovirus infection has only come into the scientific spotlight over the past decade. Canine circovirus was first identified in 2012 from serum samples of clinically healthy dogs. According to the literature, CanineCV infection is most often associated with gastrointestinal symptoms, respiratory lesions, as well as hematological and immunological disorders. In Hungary, the most common wild canid is the red fox (Vulpes vulpes), whose investigation may be of key importance in mapping the prevalence of CanineCV infection in the country.

Foxes carrying the virus may represent a risk to domestic dogs, and their analysis can provide important insights into the transmission pathways of the virus. Therefore, in our study, we set the following objectives: (i) screening Hungarian fox populations for the presence of CanineCV using qPCR, (ii) identifying circulating viral strains in Hungary through melting curve analysis and sequencing, (iii) and conducting phylogenetic comparisons of Hungarian strains with each other and with strains available in the GenBank, in order to investigate viral genome evolution.

We analyzed DNA extracted from 365 samples of foxes provided by the NÉBIH Veterinary Diagnostic Laboratory using a SYBR Green-based qPCR method. For positive samples, a ~500 bp segment of the viral genome was amplified and identified by Sanger-sequencing. Maximum Likelihood estimation was applied for sequence comparisons.

The virus was detected in 6.84% (25/365) of the tested population. The melting temperature of the samples ranged from 90 to 91.2 ºC, which did not allow for differentiation of distinct viral strains. The identified Hungarian sequences form a closely related phylogenetic group. Red foxes are likely to play a significant role in the spread of the virus; therefore, their examination is essential from the perspective of protecting the health of domestic dogs. In the future, we plan to include samples from all regions of Hungary, in order to obtain a more comprehensive picture of the virus’s prevalence in the wild population.