{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,24]],"date-time":"2026-06-24T06:35:40Z","timestamp":1782282940132,"version":"3.54.5"},"reference-count":50,"publisher":"Public Library of Science (PLoS)","issue":"3","license":[{"start":{"date-parts":[[2026,3,13]],"date-time":"2026-03-13T00:00:00Z","timestamp":1773360000000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"American Association of Swine Veterinarians Foundation","award":["N\/A"],"award-info":[{"award-number":["N\/A"]}]}],"content-domain":{"domain":["www.plosone.org"],"crossmark-restriction":false},"short-container-title":["PLoS One"],"abstract":"<jats:p>Porcine reproductive and respiratory syndrome (PRRS) continues to be a major threat to U.S. swine industry, as a substantial number of herds become positive and can pose a risk to other nearby farms, especially in post weaning farms as multiple of them may be overseen by one worker. Personnel moving between farms without adequate biosecurity measures, may play a role in viral spread acting as a fomite. The ability to detect and distinguish between the free PRRS virus (PRRSV) genomic RNA vs its genome found in a viable virus form on frequently touched surfaces in growing pig farms was assess in this study. Ten PRRSV positive growing pig farms in the Midwestern U.S. were visited to collect 20 environmental surface samples and eight oral fluids from each one. Environmental samples were analyzed using standard RT-qPCR and viability RT-qPCR, while oral fluids were assessed using the VetMAX\u2122 PRRSV EU &amp; NA v3.0 kit. The virus\u2019 RNA was commonly detected on metal and plastic (non-porous) surfaces (e.g., pig pen top rail, mortality handling equipment\u2019s handle) from all farms, with 80 out of 200 environmental samples testing positive. Viable virus was detected in 48 samples across six farms, with non-porous materials testing positive more frequently. A generalized linear mixed effect model suggested a negative association (OR = 0.005; 95% CI 0.00, 6.82; p-value\u2009=\u20090.18) between the proportion of positive oral fluids and detecting viable virus from sampled surfaces. Agreement between the detection of RNA and viable PRRSV from surface samples using Cohen\u2019s kappa yielded perfect agreement (\u03ba\u2009=\u20091.00) from doorknobs of different locations, to low agreement (\u03ba\u2009=\u20090.29) in the floor of a specific area, among others. These results indicate the presence of viable virus on surfaces that are frequently touched by the farm\u2019s personnel. This study highlights the importance of biosecurity measures applied to the personnel and their potential role of environmental contamination and PRRSV dissemination. The use of viability RT-qPCR to detect viable PRRSV offers a practical tool in field settings to improve biosecurity protocols to reduce indirect transmission of PRRSV in swine production systems.<\/jats:p>","DOI":"10.1371\/journal.pone.0344714","type":"journal-article","created":{"date-parts":[[2026,3,13]],"date-time":"2026-03-13T17:34:37Z","timestamp":1773423277000},"page":"e0344714","update-policy":"https:\/\/doi.org\/10.1371\/journal.pone.corrections_policy","source":"Crossref","is-referenced-by-count":1,"title":["Determining farm surface porcine reproductive and respiratory syndrome virus (PRRSV) contamination through viability RT-qPCR"],"prefix":"10.1371","volume":"21","author":[{"ORCID":"https:\/\/orcid.org\/0009-0001-4640-9456","authenticated-orcid":true,"given":"Claudio Marcello","family":"Melini","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Amanda","family":"Palowski","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5991-2838","authenticated-orcid":true,"given":"Declan C.","family":"Schroeder","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2749-3496","authenticated-orcid":true,"given":"Cesar A.","family":"Corzo","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"340","published-online":{"date-parts":[[2026,3,13]]},"reference":[{"issue":"9","key":"pone.0344714.ref001","doi-asserted-by":"crossref","first-page":"223","DOI":"10.1136\/vr.e1386","article-title":"Control or eradication? Costs and benefits in the case of PRRSV","volume":"170","author":"L Fraile","year":"2012","journal-title":"Vet Rec"},{"key":"pone.0344714.ref002","article-title":"The financial impact of PRRS virus","volume-title":"The porcine reproductive and respiratory syndrome compendium","author":"J Holck","year":"2003","edition":"2"},{"issue":"2","key":"pone.0344714.ref003","doi-asserted-by":"crossref","first-page":"72","DOI":"10.54846\/jshap\/754","article-title":"Assessment of the economic impact of porcine reproductive and respiratory syndrome virus on United States pork producers","volume":"21","author":"D Holtkamp","year":"2013","journal-title":"JSHAP"},{"key":"pone.0344714.ref004","first-page":"189","article-title":"Updates on the economic impact of PRRSV to US pork producers","author":"O Osemeke","year":"2024","journal-title":"2024 Allen D Leman Swine Conference Research Abstracts and Proceedings. Saint Paul, Minnesota, USA: University of Minnesota"},{"key":"pone.0344714.ref005","article-title":"Interpreting MSHMP\u2019s Chart 1 for PRRS and PEDv","author":"M Kikuti","year":"2019","journal-title":"Morrison Swine Health Monitoring Program"},{"issue":"5","key":"pone.0344714.ref006","doi-asserted-by":"crossref","first-page":"261","DOI":"10.54846\/jshap\/1218","article-title":"Proposed modifications to porcine reproductive and respiratory syndrome virus herd classification","volume":"29","author":"D Holtkamp","year":"2021","journal-title":"JSHAP"},{"key":"pone.0344714.ref007","article-title":"MSHMP Team","year":"2023","journal-title":"Review of MSHMP PRRS Chart 2"},{"key":"pone.0344714.ref008","doi-asserted-by":"crossref","first-page":"105976","DOI":"10.1016\/j.prevetmed.2023.105976","article-title":"Infection dynamics and incidence of wild-type porcine reproductive and respiratory syndrome virus in growing pig herds in the U.S. Midwest","volume":"217","author":"J Angulo","year":"2023","journal-title":"Prev Vet Med"},{"key":"pone.0344714.ref009","unstructured":"Montoya J, Kikuti M, Vilalta C, Sanhueza J, Corzo CA. PRRSV farm prevalence in near-to-market-pigs in the United States. 52nd AASV Annual Meeting Navigate the future. together. Virtual: American Association of Swine Veterinarians; 2021. p. 424."},{"issue":"1","key":"pone.0344714.ref010","doi-asserted-by":"crossref","first-page":"5","DOI":"10.1186\/s40813-020-00181-z","article-title":"Biosecurity in pig farms: a review","volume":"7","author":"LV Alarc\u00f3n","year":"2021","journal-title":"Porcine Health Manag"},{"issue":"7","key":"pone.0344714.ref011","doi-asserted-by":"crossref","first-page":"1134","DOI":"10.3390\/ani14071134","article-title":"Biosecurity Insights from the United States Swine Health Improvement Plan: Analyzing Data to Enhance Industry Practices","volume":"14","author":"M Harlow","year":"2024","journal-title":"Animals (Basel)"},{"issue":"1","key":"pone.0344714.ref012","doi-asserted-by":"crossref","first-page":"34","DOI":"10.1186\/s40813-024-00387-5","article-title":"Assessment of porcine reproductive and respiratory syndrome virus (PRRSV) farm surface contamination through environmental sampling","volume":"10","author":"CM Melini","year":"2024","journal-title":"Porcine Health Manag"},{"issue":"1","key":"pone.0344714.ref013","doi-asserted-by":"crossref","DOI":"10.1371\/journal.pone.0291181","article-title":"Assessment of temperature and time on the survivability of porcine reproductive and respiratory syndrome virus (PRRSV) and porcine epidemic diarrhea virus (PEDV) on experimentally contaminated surfaces","volume":"19","author":"M Mil-Homens","year":"2024","journal-title":"PLoS One"},{"issue":"2","key":"pone.0344714.ref014","doi-asserted-by":"crossref","first-page":"66","DOI":"10.54846\/jshap\/1369","article-title":"Comparative survival of ten porcine reproductive and respiratory syndrome virus strains at three temperatures","volume":"32","author":"A Quinonez-Munoz","year":"2024","journal-title":"JSHAP"},{"issue":"1","key":"pone.0344714.ref015","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1186\/s12985-023-02272-z","article-title":"Unexpected thermal stability of two enveloped megaviruses, Emiliania huxleyi virus and African swine fever virus, as measured by viability PCR","volume":"21","author":"C Balestreri","year":"2024","journal-title":"Virol J"},{"key":"pone.0344714.ref016","doi-asserted-by":"crossref","first-page":"28","DOI":"10.1186\/s40813-020-00168-w","article-title":"Guidelines for oral fluid-based surveillance of viral pathogens in swine","volume":"6","author":"A Henao-Diaz","year":"2020","journal-title":"Porcine Health Manag"},{"key":"pone.0344714.ref017","doi-asserted-by":"crossref","first-page":"20","DOI":"10.1016\/j.vetmic.2017.02.004","article-title":"Sampling guidelines for oral fluid-based surveys of group-housed animals","volume":"209","author":"ML Rotolo","year":"2017","journal-title":"Vet Microbiol"},{"issue":"6","key":"pone.0344714.ref018","doi-asserted-by":"crossref","first-page":"608","DOI":"10.3390\/vaccines9060608","article-title":"Phylogenetic Structure and Sequential Dominance of Sub-Lineages of PRRSV Type-2 Lineage 1 in the United States","volume":"9","author":"IAD Paploski","year":"2021","journal-title":"Vaccines (Basel)"},{"key":"pone.0344714.ref019","article-title":"Phylogenetic-based methods for fine-scale classification of PRRSV-2 ORF5 sequences: a comparison of their robustness and reproducibility","author":"K VanderWaal","year":"2024","journal-title":"openRxiv"},{"issue":"6","key":"pone.0344714.ref020","doi-asserted-by":"crossref","DOI":"10.1128\/spectrum.02916-23","article-title":"Refining PRRSV-2 genetic classification based on global ORF5 sequences and investigation of their geographic distributions and temporal changes","volume":"11","author":"W Yim-Im","year":"2023","journal-title":"Microbiol Spectr"},{"key":"pone.0344714.ref021","author":"DN Makau","year":"2024","journal-title":"PRRSLoom"},{"key":"pone.0344714.ref022","article-title":"R: a language and environment for statistical computing","year":"2024","journal-title":"Vienna, Austria: R Foundation for Statistical Computing"},{"key":"pone.0344714.ref023","doi-asserted-by":"crossref","DOI":"10.18637\/jss.v067.i01","article-title":"Fitting linear mixed-effects models using lme4","volume":"67","author":"D Bates","year":"2015","journal-title":"J Stat Softw"},{"key":"pone.0344714.ref024","article-title":"psych: Procedures for Psychological, Psychometric, and Personality Research","author":"W Revelle","year":"2025","journal-title":"Evanston, Illinois: Northwestern University"},{"key":"pone.0344714.ref025","article-title":"vcd: Visualizing Categorical Data","author":"D Meyer","year":"2023"},{"issue":"1","key":"pone.0344714.ref026","doi-asserted-by":"crossref","first-page":"3","DOI":"10.2307\/3315487","article-title":"Beyond kappa: A review of interrater agreement measures","volume":"27","author":"M Banerjee","year":"1999","journal-title":"Can J Statistics"},{"issue":"3","key":"pone.0344714.ref027","doi-asserted-by":"crossref","first-page":"276","DOI":"10.11613\/BM.2012.031","article-title":"Interrater reliability: the kappa statistic","volume":"22","author":"ML McHugh","year":"2012","journal-title":"Biochem Med (Zagreb)"},{"key":"pone.0344714.ref028","unstructured":"Tang W, Hu J, Zhang H, Wu P, He H. Kappa coefficient: a popular measure of rater agreement. 2015;27."},{"issue":"1","key":"pone.0344714.ref029","doi-asserted-by":"crossref","first-page":"14816","DOI":"10.1038\/s41598-019-51473-6","article-title":"Environmental distribution of Porcine Circovirus Type 2 (PCV2) in swine herds with natural infection","volume":"9","author":"G L\u00f3pez-Lorenzo","year":"2019","journal-title":"Sci Rep"},{"issue":"24","key":"pone.0344714.ref030","doi-asserted-by":"crossref","first-page":"3515","DOI":"10.3390\/ani12243515","article-title":"Presence of Porcine Circovirus Type 2 in the Environment of Farm Facilities without Pigs in Long Term-Vaccinated Farrow-to-Wean Farms","volume":"12","author":"G L\u00f3pez-Lorenzo","year":"2022","journal-title":"Animals (Basel)"},{"issue":"4","key":"pone.0344714.ref031","doi-asserted-by":"crossref","first-page":"192","DOI":"10.54846\/jshap\/1077","article-title":"Comparison of shower-in and shower-in plus bench entry protocols for prevention of environmental contamination due to personnel entry in a commercial swine facility","volume":"26","author":"A Anderson","year":"2018","journal-title":"JSHAP"},{"issue":"2","key":"pone.0344714.ref032","doi-asserted-by":"crossref","first-page":"296","DOI":"10.1111\/tbed.13707","article-title":"Stability of SARS\u2010CoV\u20102 and other coronaviruses in the environment and on common touch surfaces and the influence of climatic conditions: A review","volume":"68","author":"HA Aboubakr","year":"2020","journal-title":"Transbounding Emerging Dis"},{"issue":"1","key":"pone.0344714.ref033","doi-asserted-by":"crossref","first-page":"47","DOI":"10.1093\/infdis\/146.1.47","article-title":"Survival of influenza viruses on environmental surfaces","volume":"146","author":"B Bean","year":"1982","journal-title":"J Infect Dis"},{"issue":"1","key":"pone.0344714.ref034","doi-asserted-by":"crossref","first-page":"22868","DOI":"10.1038\/s41598-021-00843-0","article-title":"SARS-CoV-2 virus transfers to skin through contact with contaminated solids","volume":"11","author":"S Behzadinasab","year":"2021","journal-title":"Sci Rep"},{"issue":"2","key":"pone.0344714.ref035","doi-asserted-by":"crossref","DOI":"10.1093\/lambio\/ovac068","article-title":"Method validation for the recovery of the porcine respiratory and reproductive syndrome virus, a potential SARS-CoV-2 surrogate, from stainless steel","volume":"76","author":"J Dhakal","year":"2023","journal-title":"Lett Appl Microbiol"},{"issue":"3","key":"pone.0344714.ref036","doi-asserted-by":"crossref","first-page":"390","DOI":"10.2460\/javma.1996.208.03.390","article-title":"Stability of porcine reproductive and respiratory syndrome virus in the presence of fomites commonly found on farms","volume":"208","author":"EC Pirtle","year":"1996","journal-title":"J Am Vet Med Assoc"},{"issue":"22","key":"pone.0344714.ref037","doi-asserted-by":"crossref","first-page":"18238","DOI":"10.1021\/acsomega.1c06880","article-title":"Effect of Surface Porosity on SARS-CoV-2 Fomite Infectivity","volume":"7","author":"M Hosseini","year":"2022","journal-title":"ACS Omega"},{"issue":"3","key":"pone.0344714.ref038","doi-asserted-by":"crossref","first-page":"229","DOI":"10.1637\/aviandiseases-D-23-00027","article-title":"A Review of the Stability of Avian Influenza Virus in Materials from Poultry Farms","volume":"67","author":"E Spackman","year":"2023","journal-title":"Avian Dis"},{"issue":"1","key":"pone.0344714.ref039","doi-asserted-by":"crossref","first-page":"24","DOI":"10.1007\/s12560-010-9025-6","article-title":"Issues Concerning Survival of Viruses on Surfaces","volume":"2","author":"P Vasickova","year":"2010","journal-title":"Food Environ Virol"},{"issue":"1","key":"pone.0344714.ref040","doi-asserted-by":"crossref","first-page":"20210039","DOI":"10.1098\/rsfs.2021.0039","article-title":"Porous surfaces: stability and recovery of coronaviruses","volume":"12","author":"L Owen","year":"2021","journal-title":"Interface Focus"},{"issue":"2","key":"pone.0344714.ref041","doi-asserted-by":"crossref","DOI":"10.1128\/msystems.01350-20","article-title":"Indoor Dust as a Matrix for Surveillance of COVID-19","volume":"6","author":"N Renninger","year":"2021","journal-title":"mSystems"},{"issue":"1","key":"pone.0344714.ref042","first-page":"22","article-title":"Survival of Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) in the Environment","volume":"11","author":"V Lugo Mesa","year":"2024","journal-title":"Vet Sci"},{"key":"pone.0344714.ref043","doi-asserted-by":"crossref","first-page":"752938","DOI":"10.3389\/fvets.2021.752938","article-title":"Emergence of a New Lineage 1C Variant of Porcine Reproductive and Respiratory Syndrome Virus 2 in the United States","volume":"8","author":"M Kikuti","year":"2021","journal-title":"Front Vet Sci"},{"issue":"33","key":"pone.0344714.ref044","doi-asserted-by":"crossref","DOI":"10.1128\/MRA.00260-21","article-title":"Phylogenetically Distinct Near-Complete Genome Sequences of Porcine Reproductive and Respiratory Syndrome Virus Type 2 Variants from Four Distinct Disease Outbreaks at U.S. Swine Farms over the Past 6 Years","volume":"10","author":"DC Schroeder","year":"2021","journal-title":"Microbiol Resour Announc"},{"issue":"12","key":"pone.0344714.ref045","doi-asserted-by":"crossref","first-page":"1026","DOI":"10.3390\/pathogens13121026","article-title":"Establishment of an Immortalized Porcine Alveolar Macrophage Cell Line That Supports Efficient Replication of Porcine Reproductive and Respiratory Syndrome Viruses","volume":"13","author":"NV Diep","year":"2024","journal-title":"Pathogens"},{"issue":"3","key":"pone.0344714.ref046","doi-asserted-by":"crossref","DOI":"10.1128\/JCM.01757-20","article-title":"Comparison of ZMAC and MARC-145 Cell Lines for Improving Porcine Reproductive and Respiratory Syndrome Virus Isolation from Clinical Samples","volume":"59","author":"W Yim-Im","year":"2021","journal-title":"J Clin Microbiol"},{"key":"pone.0344714.ref047","doi-asserted-by":"crossref","first-page":"110058","DOI":"10.1016\/j.vetmic.2024.110058","article-title":"Detection of Mycoplasma hyopneumoniae viability using a PCR-based assay","volume":"292","author":"A Canturri","year":"2024","journal-title":"Vet Microbiol"},{"key":"pone.0344714.ref048","doi-asserted-by":"crossref","first-page":"1911","DOI":"10.3389\/fmicb.2020.01911","article-title":"Rapid Selective Detection of Potentially Infectious Porcine Epidemic Diarrhea Coronavirus Exposed to Heat Treatments Using Viability RT-qPCR","volume":"11","author":"H Puente","year":"2020","journal-title":"Front Microbiol"},{"issue":"1","key":"pone.0344714.ref049","doi-asserted-by":"crossref","DOI":"10.1371\/journal.pone.0146616","article-title":"Characterization of Viral Load, Viability and Persistence of Influenza A Virus in Air and on Surfaces of Swine Production Facilities","volume":"11","author":"V Neira","year":"2016","journal-title":"PLoS One"},{"issue":"1","key":"pone.0344714.ref050","doi-asserted-by":"crossref","first-page":"81","DOI":"10.1051\/vetres:2006044","article-title":"Effect of temperature and relative humidity on the stability of infectious porcine reproductive and respiratory syndrome virus in aerosols","volume":"38","author":"J Hermann","year":"2007","journal-title":"Vet Res"}],"updated-by":[{"DOI":"10.1371\/journal.pone.0352265","type":"correction","label":"Correction","source":"publisher","updated":{"date-parts":[[2026,6,23]],"date-time":"2026-06-23T00:00:00Z","timestamp":1782172800000}}],"container-title":["PLOS One"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0344714","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,3,13]],"date-time":"2026-03-13T17:34:46Z","timestamp":1773423286000},"score":1,"resource":{"primary":{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0344714"}},"subtitle":[],"editor":[{"given":"Grzegorz","family":"Wo\u017aniakowski","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"editor"}]}],"short-title":[],"issued":{"date-parts":[[2026,3,13]]},"references-count":50,"journal-issue":{"issue":"3","published-online":{"date-parts":[[2026,3,13]]}},"URL":"https:\/\/doi.org\/10.1371\/journal.pone.0344714","relation":{},"ISSN":["1932-6203"],"issn-type":[{"value":"1932-6203","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,3,13]]}}}