Evolutionary Status of Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) Variants in Swine Farms in Lima, Peru: A Review of Molecular and Epidemiological Evidence through 2026

Porcine reproductive and respiratory syndrome (PRRS) is a major economically important disease affecting the global swine industry. Its etiological agent, porcine reproductive and respiratory syndrome virus (PRRSV), exhibits substantial genetic diversity driven by mutation, recombination, and selective pressures. Following taxonomic revisions by the International Committee on Taxonomy of Viruses, PRRSV isolates are classified into Betaarterivirus europensis and Betaarterivirus americense. In Peru, the molecular and epidemiological evolution of PRRSV in Lima’s swine farms remains insufficiently characterized. This review aimed to characterize the evolutionary dynamics of PRRSV variants circulating in Lima through 2026. A narrative review with a systematic search strategy was conducted following PRISMA 2020 principles. Searches of PubMed/MEDLINE, Scopus, Web of Science, SciELO, Redalyc, LILACS, and GenBank identified 200 records, of which 60 met the eligibility criteria. Studies addressed global taxonomy and molecular biology (50.0%), international evolutionary dynamics (25.0%), South American epidemiology (8.3%), and PRRSV evolution in Lima (16.7%). Evidence suggests three periods: European-genotype detection (1998-2012); increased epidemiological characterization and reports of genetically distinct or highly virulent lineages (2013-2022); and diversification of B. americense, including NADC34-like sublineages and field-strain recombination evidence (2022-2026). These findings support sustained genomic surveillance, whole-genome sequencing, and coordinated molecular monitoring across South America.