{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,11,15]],"date-time":"2025-11-15T10:37:09Z","timestamp":1763203029661,"version":"build-2065373602"},"reference-count":23,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2025,4,25]],"date-time":"2025-04-25T00:00:00Z","timestamp":1745539200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Merck Animal Health"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Viruses"],"abstract":"<jats:p>The purpose of this study was to determine any associations of EHV-2, EHV-5, and dual infection with EHV-2\/-5 with demographic parameters, clinical signs, and coinfection with other common respiratory pathogens. Nasal swabs collected from 9737 horses were tested for EHV-2 and EHV-5, as well as EHV-1, EHV-4, EIV, S equi, ERAV, and ERBV, by qPCR. Clinical signs and demographic parameters were recorded, and prevalence factors were evaluated for significance regarding EHV-2 and\/or EHV-5 infection. Out of the 9737 horses in this study, 17.8% tested EHV-2-positive (n = 1731), 15.8% tested EHV-5-positive (n = 1536), 33.4% tested positive for both viruses EHV-2\/-5 (n = 3247), and 33.1% tested negative for both viruses (n = 3223). When comparing EHV-2 and\/or EHV-5 infected horses to horses testing qPCR-negative for both viruses, horses infected with EHV-2 alone were more likely to be younger Thoroughbreds with a history of recent transportation, presenting with fever, and having a higher rate of coinfections with EHV-4 and S. equi. Horses infected with EHV-5 alone were less likely to be used for pleasure purposes, had fewer clinical signs, and were more likely to be coinfected with EHV-4. Horses dually infected with EHV-2 and EHV-5 were much more likely to be younger, used for competition, presenting with a fever, and coinfected with additional respiratory pathogens. It is apparent from the study population that horses infected with EHV-2 alone or in combination with EHV-5 had breed predilections, greater frequency of clinical signs, and a higher rate of coinfections with EHV-4, ERBV, and S. equi.<\/jats:p>","DOI":"10.3390\/v17050612","type":"journal-article","created":{"date-parts":[[2025,4,25]],"date-time":"2025-04-25T04:08:24Z","timestamp":1745554104000},"page":"612","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Investigation of Selected Prevalence Factors Associated with EHV-2 and\/or EHV-5 Infection in Horses with Acute Onset of Fever and Respiratory Signs"],"prefix":"10.3390","volume":"17","author":[{"given":"Kaitlyn","family":"James","sequence":"first","affiliation":[{"name":"Department of Obstetrics, Gynecology and Reproduction Biology, Massachusetts General Hospital, Boston, MA 02114, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9978-5546","authenticated-orcid":false,"given":"Duane E.","family":"Chappell","sequence":"additional","affiliation":[{"name":"Merck Animal Health, Rahway, NJ 07065, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Bryant","family":"Craig","sequence":"additional","affiliation":[{"name":"Merck Animal Health, Rahway, NJ 07065, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7462-4532","authenticated-orcid":false,"given":"Chrissie","family":"Pariseau","sequence":"additional","affiliation":[{"name":"Merck Animal Health, Rahway, NJ 07065, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Cara","family":"Wright","sequence":"additional","affiliation":[{"name":"Merck Animal Health, Rahway, NJ 07065, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Philip","family":"van Harreveld","sequence":"additional","affiliation":[{"name":"Merck Animal Health, Rahway, NJ 07065, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Samantha","family":"Barnum","sequence":"additional","affiliation":[{"name":"Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, CA 95616, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Nicola","family":"Pusterla","sequence":"additional","affiliation":[{"name":"Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, CA 95616, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2025,4,25]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"148","DOI":"10.1016\/j.tvjl.2009.08.017","article-title":"Equine gammaherpesviruses: Pathogenesis, epidemiology and diagnosis","volume":"186","author":"Fortier","year":"2010","journal-title":"Vet. 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