We conducted a cross-sectional study to identify the major respiratory pathogen responsible for an outbreak of respiratory disease at a swine farm in West Siberia in 2019. We discovered that the peak of morbidity and mortality coincided with a high level of porcine reproductive and respiratory syndrome virus (PRRSV) 1 and 2-related viremia. Based on longer PRRSV2 viremia, the dominant role of PRRSV2 over PRRSV1 in the outbreak was assumed. Phylogenetic analysis revealed that the PRRSV1 strain belonged to sub-genotype 2—one of the predominant groups of genotype 1 PRRSVs in Russia. A partial open reading frame 7 sequence of the PRRSV2 isolate demonstrated a high identity with modified live vaccine-related strains from Denmark (93%) and wild-type VR2332 (92%). We identified the first instance of PRRSV1/PRRSV2 mixed infection in Russia. This finding indicates that further field investigations are needed to access PRRSV2 epidemiology in eastern Europe.

Porcine parvoviruses (PPVs) are widespread worldwide in the swine population. PPV1 is a significant infectious agent in pig production, causing porcine reproductive failure. The pathogenic potential of novel PPVs has been poorly studied. Since wild boars are a reservoir for PPVs, the aim of this study was to investigate their prevalence and genetic diversity in the wild boar population. Tissue samples (spleen, lungs, and lymph nodes) collected from 108 wild boars from three regions of Russia during 2021–2024 were analyzed. PPV1–7 were found in wild boar populations in Russia, and the most abundant species were PPV7 (59.3%) and PPV3 (49.1%). The research did not reveal any significant relationship between the gender and age of the animals and the prevalence of PPVs. A comparison between the detection rates of PPVs and PCV2/PCV3 revealed the random nature of coinfections. For phylogenetic analysis, complete VP1/VP2 gene sequences of 17 PPV1 isolates were obtained. Most of them belonged to the 27a-like group. Two isolates were in the same cluster as the highly virulent Kresse strain. Isolate BelWB57 had amino acid substitutions that were specific to both the Kresse and 27a-like strains, but it was not classified in either group. Additionally, three sequences for PPV2, PPV3, and PPV7, and one sequence for PPV5 and PPV6 VP1/VP2 genes were obtained. PPV2, PPV3, and PPV7 isolates demonstrated distribution across various clusters with strains from domestic pigs and wild boars from different countries. PPV6 isolate was included in the same clade as the Russian isolate from a domestic pig, whereas PPV5 did not enter any clade with representatives from our country. This is the first work devoted to the study of the PPV1–7 prevalence, as well as the genetic characteristics of isolates circulating among wild boars in various regions of Russia. Our data showed that PPV1–7 is widespread in wild boar populations. Phylogenetic analysis of PPV1 demonstrates a significant prevalence of 27a-like isolates.

A molecular genetic analysis of genomes of porcine reproductive respiratory syndrome virus (PRRSV) and porcine circovirus type 2 (PCV-2) circulating in the territory of the Russian Federation is given. The results of the study showed the presence of circulation of European genotypes of PRRSV strains that are similar to isolates found in France and Denmark from 1998 to 2001. We explained the homology of a fragment of one of the genes between the Russian isolates and the vaccine strain used in Porcilis PRRS (Intervet) vaccine, but this requires further study. Strains of the North American genotype of PRRS were not found. The PCV-2 genomes fall into three separate groups. One (genotype 2b) is formed by isolates in Malaysia, Brazil, Switzerland, China, Slovakia, the United Kingdom, and the United States, which were isolated during the period from 2004 to the present time. The second group consists of the field sequences of viruses isolated in 2000–2012 in Canada, the United States, China, and South Korea (genotype 2a). The third group is formed by highly pathogenic isolates evolved in 2013 in China (genotype 2c). The circulation of all three known genotypes of PCV-2-2a, 2b, and 2c-in the Russian Federation was shown.