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In this report, we describe the detection of bovine viral diarrhea virus (BVDV) contamination in commercial animal-derived sera and vaccines against animal viral pathogens on the market in Poland. Antibodies against BVDV were detected in 4/45 sera samples (8.9%) using an ELISA test. The presence of BVDV antigen was found using ELISA in 3/45 serum samples (6.6%) and 18/172 vaccine samples (10.5%). An RT -PCR was conducted using primers targeting two genome regions, the five prime untranslated region (5’UTR) and N-terminal protease (Npro). BVDV RNA was detected in 33/45 (73.3%) of sera, and 11/172 samples (6.4%) of collected vaccines, of which one vaccine did not declare BVDV strain in its composition. A single serum showed the presence of an infectious virus and only one was contaminated with all 3 species of BVDV. The most frequent species in sera was BVDV-3 (75.5%), whereas in vaccines only BVDV-1 was identified. Sequence analysis showed that the tested commercial sera and one vaccine were contaminated by six genotypes of BVDV: -1a, -1b, -1c, -1d, -2a, and -3. Identification of BVDV and its genetic material in animal-derived products is important due to the possibility of pestivirus transmission as well as the chance of falsifying the results of a diagnostic test. It also demonstrates the necessity of rigorous monitoring of the bioproducts used at the laboratory and industry level.

The 2 predominant circulating subtypes of influenza A virus in the dog population, equine-origin H3N8 and avian-origin H3N2, constitute a potential zoonotic risk. We determined the prevalence of influenza A antibodies in 496 dogs in Poland and found 2.21% of sera positive by commercial ELISA. Hemagglutination inhibition (HI) assays indicated 7.25% of sera positive using equine H3N8, swine H3N2, and pandemic H1N1 antigens, with the most frequently detected immune response being to H3N2. Considering interspecies transfer, reassortment ability, and close contact between dogs and humans, infections of dogs with influenza A virus should be monitored.

The study was performed on nasal swabs, tracheal samples, and sera obtained from young beef heifers aged between 6 and 12 months, from farms in eastern and south-eastern Poland. The samples were evaluated using bovine herpesvirus 1 (BHV-1) ELISA kits (ELISA BHV1 antibody and ELISA BHV1 antigen) and PCR. Among all the animals examined, 37 (32.2%) were positive in the ELISA BHV1 antigen test. The presence of BHV-1 was confirmed by PCR in 42 (36.5%) animals. In the ELISA BHV1 antibody test, 39 (33.9%) seropositive animals were identified. The presence of BHV-1 positive samples was observed in all the examined breeds of young cattle. There were no significant differences (P ≤ 0.05) in BHV-1 positive samples. The results indicate that the incidence of BHV-1 infections in feedlot cattle herds studied was 32.2%-36.5%, which suggests that preventive measures should be implemented in order to limit transmission of the virus.

The variability of the ORF2a, ORF2b, ORF3, and ORF4 genes of the equine arteritis virus (EAV) was analysed during a seven year observation of persistent infection in a stallion of the Malopolska breed. A total of 11 semen samples were collected between 2004 and 2011. RNA of EAV isolates obtained from the semen of the stallion was amplified, sequenced, and compared with the sequences of other strains available in GenBank. Multiple nucleotide substitutions were found in sequences of the analysed regions, however, neither deletion nor insertions were detected. The highest number of point mutations (11-6 synonymous and 5 non-synonymous) were found in the ORF2b gene, and the lowest number of substitutions (6-5 synonymous and one non-synonymous) were found in the ORF2a gene. None of the identified mutations affected any of the glycosylation or phosphorylation sites of the minor EAV protein. Phylogenetic analysis of the ORF3 gene of EAV isolates showed that they grouped together within the cluster of European strains of EAV. Additionally, the ORF3 gene sequences of the isolates showed high (86.4% - 98.3%) similarity to the previously isolated Polish EAV strains.

ABSTRACTThe aim of the study was to assess the occurrence of bovine respiratory syncytial virus (BRSV) and bovine herpesvirus 1 (BHV-1) in herds of European (Polish) bison in the Białowieża National Park. The materials consisted of nasal swabs and sera (n = 35) obtained from male and female Polish bison ranging in age from 1 to 3 years. Anti-BRSV and BHV-1 antibodies were detected using commercially available indirect Enzyme-linked immunosorbent assay (ELISA) kits. The occurrence of BHV-1 and BRSV was confirmed using polymerase chain reaction (PCR) and reverse transcription (RT-PCR) methods, respectively. In the examined nasal samples and sera only 3 of 35 were BRSV positive using the ELISA kit and in RT-PCR. In the case of BHV-1, 6 of the 35 samples were positive in ELISA and PCR methods. Of the six individuals that tested positive for BHV-1, three were also seropositive for BRSV. Individuals reacting positively in the ELISA assay were confirmed using PCR for BHV-1 and in RT-PCR for BRSV. In summary, these studies confirm the presence of BRSV and BHV-1 viruses in European Bison in Poland, and should be continued in more herds of bison in Poland.

Tick-borne encephalitis (TBE) is one of the most common zoonotic diseases in Europe transmitted by Ixodidae vectors. While small mammals such as bank voles and ticks constitute the main reservoirs for virus transmission, large sylvatic species act as a food source for ticks. Cervids such as roe deer and red deer are considered sentinel species for TBE in natural foci. In addition, an increase of the population size and density of large wild mammals in an area corresponds to an increase in the tick burden and may potentially increase the prevalence of TBE virus (TBEV) in ticks and tick hosts and further exposure risk in humans. Humans are considered accidental hosts. The prevalence of TBE relies on interactions between host, vector and environment. The present study examines the exposure of the largest European herbivore, the European bison (Bison bonasus) to TBEV infection. Assessed using the IMMUNOZYM FSME ELISA (PROGEN), the overall TBEV seroprevalence was 62.7% in the 335 European bison that were studied. ELISA results were confirmed by the gold-standard virus neutralization test (VNT) with 98.7% sensitivity and thus giving a true prevalence of 63.5%. TBEV seroprevalence was significantly correlated to the origin, age group, sex, population type (free living/captive) and sanitary status (healthy/selectively eliminated/found dead/killed in accident) of the European bison in the univariable analysis. The highest seroprevalences were observed in the three largest north-eastern wild populations (Białowieska, Borecka and Knyszyńska forests), which corresponded with the highest incidence of human cases reported in the country. The risk of TBEV seropositivity increased with age and was higher in female and free-ranging European bison. Additionally, to the epidemiological investigation, the continuous detection of TBEV antibodies was studied by repetitive testing of animals over the course of 34 months. Two of six seropositive animals remained seropositive throughout the study. The presence of antibodies was followed throughout the study in seropositive European bison and for at least a year in animals that seroconverted during the observation period.