Leman: PRRSV variant 1C.5.32 in Iowa Since 2023 PRRSV sublineage 1C.5.32 has spread rapidly across Iowa11 August 2026 11 August 2026 1 minute read 1 minute read By: By: Chris Wright North America[Excerpts of a presentation by Rabsa Naseer, Iowa State University Veterinary Diagnostic Laboratory and colleagues at Iowa State University, USA, during the 2025 Leman Swine Conference]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. In 2023, an unprecedented clonal expansion within 1C.5, designated as variant 1C.5.32, was identified in Iowa. Compared to other major lineages, variant 1C.5.32 displays lower reverse transcription quantitative polymerase chain reaction (RT-qPCR) cycle threshold (Ct) values, suggesting higher viral loads. The 1C.5.32 variant sequences were screened for further recombination with RDP5, but none were detected.