Global review finds PRRSV remains widespread in pigs and wild boars

Porcine reproductive and respiratory syndrome virus remains deeply entrenched in global swine production, according to a new systematic review and meta-analysis in Veterinary Sciences that pooled serology data from pigs and wild boars worldwide. The authors, Giulia Graziosi, Consiglia Longobardi, and Caterina Lupini, conclude that PRRSV is still widespread, with higher prevalence linked mainly to animal density, while published data remain limited for many countries. The paper also notes that wild boar seropositivity has been reported, especially near pig farms, but available evidence suggests only limited wild boar-to-wild boar spread and an uncertain role as a sustained reservoir. At the same time, newer strain-level work from China underscores that the virus's global footprint is not just broad but biologically diverse: investigators in southwestern China recently isolated a European-like PRRSV-1 strain from Sichuan piglets and found it could still cause fever, respiratory signs, growth retardation, and mortality, even if disease was less severe than that caused by a comparison NADC30-like PRRSV-2 strain. (mdpi.com)

Why it matters: For veterinarians and swine health teams, the review reinforces that PRRSV is still a surveillance and biosecurity problem, not a solved one. WOAH continues to classify PRRS as a listed disease affecting domestic and captive wild pigs, and the virus remains economically significant: Iowa State University reported in 2024 that PRRS was associated with an estimated $1.2 billion in annual U.S. production losses from 2016 to 2020, up 80% from a decade earlier. For practitioners, the takeaway is familiar but important: herd density, animal movements, replacement introductions, and regional transmission pressure still shape risk, and wildlife interface questions shouldn't be ignored even if wild boars appear to be a weaker maintenance host than domestic swine. The newer China data add another practical reminder: PRRSV-1 and PRRSV-2 differences matter on the ground, because emerging PRRSV-1 lineages can produce clinically important disease while showing different pathogenicity profiles from better-known PRRSV-2 strains. (woah.org)

What to watch: Expect follow-up work to focus less on whether PRRSV is globally widespread, and more on where surveillance gaps, strain differences, and domestic pig-wild suid interfaces are still undermining control. That includes closer attention to PRRSV-1 emergence in places such as China, where a BJEU06-1-like strain was recently characterized without detectable recombination and with lung and tonsil tropism in challenged piglets, adding to evidence that local strain evolution and pathogenicity differences could complicate control planning. (mdpi.com)