The diagnosis of feline leukaemia virus (FeLV) infection in owned and group-housed rescue cats in Australia

Westman, M. et al. (2019) The diagnosis of feline leukaemia virus (FeLV) infection in owned and group-housed rescue cats in Australia. Viruses, 11(6), 503. (doi: 10.3390/v11060503) (PMID:31159230) (PMCID:PMC6630418)

Abstract

A field study was undertaken to (i) measure the prevalence of feline leukaemia virus (FeLV) exposure and FeLV infection in a cross-section of healthy Australian pet cats; and (ii) investigate the outcomes following natural FeLV exposure in two Australian rescue facilities. Group 1 (n = 440) consisted of healthy client-owned cats with outdoor access, predominantly from eastern Australia. Groups 2 (n = 38) and 3 (n = 51) consisted of a mixture of healthy and sick cats, group-housed in two separate rescue facilities in Sydney, Australia, tested following identification of index cases of FeLV infection in cats sourced from these facilities. Diagnostic testing for FeLV exposure/infection included p27 antigen testing using three different point-of-care FeLV kits and a laboratory-based ELISA, real-time polymerase chain reaction (qPCR) testing to detect FeLV proviral DNA in leukocytes, real-time reverse-transcription PCR (qRT-PCR) testing to detect FeLV RNA in plasma, and neutralising antibody (NAb) testing. Cats were classified as FeLV-uninfected (FeLV-unexposed and presumptively FeLV-abortive infections) or FeLV-infected (presumptively regressive and presumptively progressive infections). In Group 1, 370 FeLV-unexposed cats (370/440, 84%), 47 abortive infections (47/440, 11%), nine regressive infections (9/440, 2%), and two progressive infections (2/440, 0.5%) were identified, and 12 FeLV-uninfected cats (12/440, 3%) were unclassifiable as FeLV-unexposed or abortive infections due to insufficient samples available for NAb testing. In Groups 2 and 3, 31 FeLV-unexposed cats (31/89, 35%), eight abortive infections (8/89, 9%), 22 regressive infections (22/89; 25%), and 19 progressive infections (19/89; 21%) were discovered, and nine FeLV-uninfected cats (9/89; 10%) were unclassifiable due to insufficient samples available for NAb testing. One of the presumptively progressively-infected cats in Group 3 was likely a focal FeLV infection. Two other presumptively progressively-infected cats in Group 3 may have been classified as regressive infections with repeated testing, highlighting the difficulties associated with FeLV diagnosis when sampling cats at a single time point, even with results from a panel of FeLV tests. These results serve as a reminder to Australian veterinarians that the threat of FeLV to the general pet cat population remains high, thus vigilant FeLV testing, separate housing for FeLV-infected cats, and FeLV vaccination of at-risk cats is important, particularly in group-housed cats in shelters and rescue facilities, where outbreaks of FeLV infection can occur.

• Item Type: Articles
• Additional Information: This research was supported financially by the Australian Companion Animal Health Foundation (grant numbers 006/2013 and 004/2015) and Boehringer Ingelheim Animal Health, Australia. Mark Westman was supported by an Australian Postgraduate Award (APA), the Neil and Allie Lesue Scholarship, the Herbert Johnson Travel Grant Scholarship, and an Australian Endeavour Fellowship. Richard Malik was supported by the Valentine Charlton Bequest. The molecular work was partially performed using the logistics of the Centre for Clinical Studies, Vetsuisse Faculty, University of Zurich.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Hosie, Professor Margaret and Westman, Dr Mark and McDonald, Mr Mike

Creator Roles

Westman, M.: Conceptualization, Visualization, Methodology, Investigation, Data curation, Writing – original draft, Writing – review and editing, Project administration, Funding acquisition
McDonald, M.: Data curation, Writing – review and editing
Hosie, M.: Conceptualization, Visualization, Methodology, Writing – review and editing, Supervision, Project administration, Funding acquisition

• Authors: Westman, M., Norris, J., Malik, R., Hofmann-Lehmann, R., Harvey, A., McLuckie, A., Perkins, M., Schofield, D., Marcus, A., McDonald, M., Ward, M., Hall, E., Sheehy, P., and Hosie, M.
• College/School: College of Medical Veterinary and Life Sciences > School of Infection & Immunity; College of Medical Veterinary and Life Sciences > School of Biodiversity, One Health & Veterinary Medicine; 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
• Published Online: 31 May 2019
• Copyright Holders: Copyright © 2019 The Authors
• First Published: First published in Viruses 11(6):503
• Publisher Policy: Reproduced under a Creative Commons License