A Molecular and Epidemiological Description of a Severe Porcine Reproductive and Respiratory Syndrome Outbreak in a Commercial Swine Production System in Russia

• Published in: Viruses Vol. 14; no. 2; p. 375
• Main Authors: Havas, Karyn A, Makau, Dennis N, Shapovalov, Sergei, Tolkova, Ekaterina, VanderWaal, Kim, Tkachyk, Tymofii, Spronk, Gordon D, Heron, Brad, Dee, Scott A, Perez, Andres
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 11.02.2022; MDPI
• Subjects: Animal diseases; Animals; Communication; Disease Outbreaks - veterinary; Disease spread; Epidemics; Epidemiological Monitoring; Epidemiology; Evolution, Molecular; Farms; Genetic distance; Hogs; Laboratories; Molecular Epidemiology; Outbreaks; Phylogeny; Polymerase chain reaction; Porcine Reproductive and Respiratory Syndrome - epidemiology; Porcine Reproductive and Respiratory Syndrome - virology; Porcine respiratory and reproductive syndrome virus - genetics; Porcine respiratory and reproductive syndrome virus - isolation & purification; Quarantine; RNA-directed DNA polymerase; Russia - epidemiology; Swine; Swine Diseases - epidemiology; Swine Diseases - virology; swine production; Vaccines; viral emergence; viral evolution; viral transmission; Russia; United States > US; molecular epidemiology; viral evolution; viral transmission; viral emergence; swine production
• ISSN: 1999-4915; 1999-4915
• DOI: 10.3390/v14020375

Porcine reproductive and respiratory syndrome (PRRS) is an economically devastating disease of swine in many parts of the world. Porcine reproductive and respiratory syndrome virus (PRRSV) type 1 is endemic in Europe, and prevalence of the subtypes differ spatially. In this study, we investigated a severe PRRS outbreak reported in 30 farms located in eastern Russia that belong to a large swine production company in the region that was also experiencing a pseudorabies outbreak in the system. Data included 28 ORF5 sequences from samples across 18 of the 25 infected sites, reverse transcriptase real-time polymerase chain reaction (RT-qPCR) results from diagnostic testing, reports of clinical signs, and animal movement records. We observed that the outbreak was due to two distinct variants of wildtype PRRSV type 1 subtype 1 with an average genetic distance of 15%. Results suggest that the wildtype PRRSV variants were introduced into the region around 2019, before affecting this production system (i.e., sow farms, nurseries, and finisher farms). Clinical signs did not differ between the variants, but they did differ by stage of pig production. Biosecurity lapses, including movement of animals from infected farms contributed to disease spread.