Leman: PRRSV variant 1C.5.32 in Iowa

The porcine reproductive and respiratory syndrome virus (PRRSV-2) remains the most economically devastating swine pathogen in the US, with losses exceeding $1 billion dollars annually. The emergence and turnover of dominant PRRSV lineages are well documented, typically occurring on a 1 to 4-year cycle. Since its emergence in 2020, sub lineage 1C.5 has spread rapidly, contributing to more than 45% of US detections. In 2023, an unprecedented clonal expansion within 1C.5, designated as variant 1C.5