What have we learned from 7 years of equine rhinitis B virus qPCR testing in nasal secretions from horses with respiratory signs

Abstract

Background: Equine rhinitis B virus (ERBV) has been given little attention by practitioners compared to other respiratory viruses, mainly because of the lack of diagnostic modalities and association with clinical disease. The objective of the study was to determine the frequency of detection of ERBV in nasal secretions from 6568 horses with acute onset of respiratory signs. Methods: ERBV-positive qPCR results from nasal secretions submitted to a molecular diagnostic laboratory from 2013 to 2019 were reviewed. Results: A total of 333 ERBV qPCR-positive samples (5.1%) were detected with increasing yearly frequency since the introduction of the assay in 2013. In comparison, only three of 356 (0.8%) healthy horses tested qPCR-positive for ERBV. Median age for ERBV qPCR-positive horses was 3 years of age, and fever, coughing and nasal discharge were the most common signs reported. Further, co-infections with other respiratory pathogens were reported in 73 (21.9%) of ERBV qPCR-positive samples. Conclusion:ERBV is a commonly detected respiratory virus from nasal secretions of young horses presenting with fever, nasal discharge and coughing.

Investigation of the Frequency of Detection of Common Respiratory Pathogens in Nasal Secretions and Environment of Healthy Sport Horses Attending a Multi-Week Show Event during the Summer Months

“…The swabs were assayed for the presence of equine influenza virus (EIV), equine herpesvirus-1 (EHV-1), EHV-4, equine rhinitis A virus (ERAV), equine rhinitis B virus (ERBV), and Streptococcus equi ss. equi ( S. equi ) using previously reported real-time TaqMan PCR assays [ 10 , 11 , 12 ].…”

Frequency of Detection and Prevalence Factors Associated with Common Respiratory Pathogens in Equids with Acute Onset of Fever and/or Respiratory Signs (2008–2021)

“…The demographic of ERVs showed similar prevalence factors as EHV-4. ERVs have been shown to mostly infect young performance horses, alone or in combination with other respiratory pathogens [ 12 , 38 , 39 , 40 ]. The role of ERVs as respiratory pathogens with clinical implication has repeatedly been documented, despite the fact that these viruses can be found sporadically in healthy horses [ 40 ].…”

“…ERVs have been shown to mostly infect young performance horses, alone or in combination with other respiratory pathogens [ 12 , 38 , 39 , 40 ]. The role of ERVs as respiratory pathogens with clinical implication has repeatedly been documented, despite the fact that these viruses can be found sporadically in healthy horses [ 40 ]. The highest frequency of EHV-1 detection was observed during the spring months and affected both young (1–4 years of age) as well as older horses (10–14 years of age).…”

“…Nasal secretions were assayed for the presence of EIV, EHV-1, EHV-4, and S. equi for all submissions using previously reported real-time TaqMan PCR assays [ 13 , 53 ]. Nasal secretions were also tested for ERAV and ERBV starting 1 September, 2012 on a total of 7720 individual submissions using previously reported qPCR assays [ 40 ]. Sample quality and efficiency of nucleic acid extraction was determined using a housekeeping gene (equine glyceraldehyde-3-phosphate dehydrogenase (e GAPDH )) as previously described [ 54 ].…”

Frequency of Detection of Respiratory Pathogens in Clinically Healthy Show Horses Following a Multi-County Outbreak of Equine Herpesvirus-1 Myeloencephalopathy in California

“…The initial swabs were tested for EHV-1 by qPCR, as previously reported [ 19 ], and the results were reported within 24 h of sample analysis to the submitting veterinary clinic. As part of the study project, purified nucleic acids were subsequently also tested for the presence of EIV, EHV-2, EHV-4, EHV-5, ERAV, ERBV, S. equi, and S. zooepidemicus using previously reported real-time TaqMan PCR assays [ 20 , 21 , 22 ]. To determine sample quality and efficiency of nucleic acid extraction, all the samples were analyzed for the presence of the housekeeping gene equine glyceraldehyde-3-phosphate dehydrogenase (eGAPDH), as previously described [ 19 ].…”