Serological and molecular investigation of SARS-CoV-2 in horses and cattle in Switzerland from 2020 to 2022

Hüttl, J. et al. (2024) Serological and molecular investigation of SARS-CoV-2 in horses and cattle in Switzerland from 2020 to 2022. Viruses, 16(2), 224. (doi: 10.3390/v16020224)

Abstract

Horses and cattle have shown low susceptibility to SARS-CoV-2, and there is no evidence of experimental intraspecies transmission. Nonetheless, seropositive horses in the US and seropositive cattle in Germany and Italy have been reported. The current study investigated the prevalence of antibodies against SARS-CoV-2 in horses and cattle in Switzerland. In total, 1940 serum and plasma samples from 1110 horses and 830 cattle were screened with a species-specific ELISA based on the SARS-CoV-2 receptor-binding domain (RBD) and, in the case of suspect positive results, a surrogate virus neutralization test (sVNT) was used to demonstrate the neutralizing activity of the antibodies. Further confirmation of suspect positive samples was performed using either a pseudotype-based virus neutralization assay (PVNA; horses) or an indirect immunofluorescence test (IFA; cattle). The animals were sampled between February 2020 and December 2022. Additionally, in total, 486 bronchoalveolar lavage (BAL), oropharyngeal, nasal and rectal swab samples from horses and cattle were analyzed for the presence of SARS-CoV-2 RNA via reverse transcriptase quantitative polymerase chain reaction (RT-qPCR). Six horses (0.5%; 95% CI: 0.2–1.2%) were suspect positive via RBD-ELISA, and neutralizing antibodies were detected in two of them via confirmatory sVNT and PVNA tests. In the PVNA, the highest titers were measured against the Alpha and Delta SARS-CoV-2 variants. Fifteen cattle (1.8%; 95% CI: 1.0–3.0%) were suspect positive in RBD-ELISA; 3 of them had SARS-CoV-2-specific neutralizing antibodies in sVNT and 4 of the 15 were confirmed to be positive via IFA. All tested samples were RT-qPCR-negative. The results support the hypotheses that the prevalence of SARS-CoV-2 infections in horses and cattle in Switzerland was low up to the end of 2022.

• Item Type: Articles
• Additional Information: This research was funded by a grant from the University of Zurich for exceptional research projects (“COVID-19 in a One-Health Context: Natural SARS-CoV-2 infection in animals and its implication control”; no. G-53420-01-01) and by the Federal Food Safety and Veterinary Office (Bundesamt für Lebensmittelsicherheit und Veterinärwesen, BLV (“COVID-19 and Domestic Animals: Study on the Situation in Switzerland, Northern Italy and Southern Germany During the Pandemic”; no. 1.20.04 0714001572).
• Keywords: SARS-CoV-2, animal, horse, cattle, serology, RT-PCR, neutralization, bovine coronavirus, one health, spillover.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Jones, Dr Sarah and Hosie, Professor Margaret and Tyson, Grace

Creator Roles

Jones, S.: Investigation
Tyson, G.: Investigation
Hosie, M.: Supervision

• Authors: Hüttl, J., Reitt, K., Meli, M. L., Meili, T., Bönzli, E., Pineroli, B., Ginders, J., Schoster, A., Jones, S., Tyson, G. B., Hosie, M. J., Pusterla, N., Wernike, K., and Hofmann-Lehmann, R.
• College/School: College of Medical Veterinary and Life Sciences > School of Infection & Immunity > Centre for Virus Research
• Journal Name: Viruses
• Publisher: MDPI
• ISSN: 1999-4915
• ISSN (Online): 1999-4915
• Copyright Holders: Copyright: © 2024 by the authors
• First Published: First published in Viruses 16(2): 224
• Publisher Policy: Reproduced under a Creative Commons licence