An Outbreak of a Respiratory Disorder at a Russian Swine Farm Associated with the Co-Circulation of and .

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 () 1 and 2-related viremia. Based on longer PRRSV2 viremia, the dominant role of PRRSV2 over PRRSV1 in the outbreak was assumed.