Evaluation of three serological tests for the diagnosis of Brucella suis in dogs using Bayesian latent class analysis

Catherine C Kneipp; Ronald Coilparampil; Mark Westman; Monica Suann; Jennifer Robson; Simon M Firestone; Richard Malik; Siobhan M Mor; Mark A Stevenson; Anke K Wiethoelter

doi:10.1016/j.prevetmed.2024.106345

Evaluation of three serological tests for the diagnosis of Brucella suis in dogs using Bayesian latent class analysis

Prev Vet Med. 2024 Sep 19:233:106345. doi: 10.1016/j.prevetmed.2024.106345. Online ahead of print.

Authors

Affiliations

¹ Melbourne Veterinary School, Faculty of Science, The University of Melbourne, Parkville, Victoria 3010, Australia. Electronic address: c.kneipp@unimelb.edu.
² The New South Wales Animal and Plant Health Laboratories at the Elizabeth Macarthur Agricultural Institute, NSW Department Primary Industries, Menangle, NSW 2568, Australia.
³ Sullivan Nicolaides Pathology, Brisbane, Queensland 4006, Australia.
⁴ Melbourne Veterinary School, Faculty of Science, The University of Melbourne, Parkville, Victoria 3010, Australia.
⁵ Centre for Veterinary Education, University of Sydney, Sydney, NSW 2006, Australia; School of Animal and Veterinary Sciences, Charles Sturt University, NSW 2678, Australia.
⁶ Institute of Infection, Veterinary and Ecological Sciences, The University of Liverpool, Liverpool L35RF, United Kingdom.

PMID: 39332104
DOI: 10.1016/j.prevetmed.2024.106345

Abstract

Brucella suis infection of dogs is an emerging issue worldwide requiring specific management to address zoonotic risks and animal welfare concerns. Diagnosis in dogs is routinely based on serological testing, but to date these tests have only been validated for use in production animal species and humans. This study aimed to assess the diagnostic performance of three commonly used serological tests in dogs. Canine sera (n = 989) were tested with the Rose Bengal rapid plate agglutination test (RBRPT), the complement fixation test (CFT) and a competitive ELISA (C-ELISA). Diagnostic test performance was evaluated using a three test, two population Bayesian latent class analysis accounting for conditional dependence between the three tests. Positive and negative predictive values (PPV, NPV) were calculated for a range of expected prevalence estimates for the individual tests and test combinations interpreted in series and parallel. The RBRPT showed the highest individual Se of 0.902 (95 % posterior credible interval [PCI] 0.759-0.978) and the CFT the highest individual diagnostic specificity (Sp) of 0.914 (95 % PCI 0.886-0.946). The C-ELISA had marginally the best overall diagnostic performance (Youden's index = 0.807). The CFT and the C-ELISA interpreted in parallel returned the highest combined Se and Sp (0.988 and 0.885, respectively). All tests returned NPVs of > 0.982 in 2-8 % prevalence settings. Series interpretation of the three-test combination as well as the two-test combinations of the RBRPT and the C-ELISA and the CFT and the C-ELISA produced a PPV of 0.502 when the estimated prevalence was 8 %. While all tests are suitable for the detection of B. suis antibodies in dogs, they should not be interpreted in isolation as their diagnostic value is dependent on the pre-test probability of the disease. As such they are useful tools for the diagnosis of B. suis in dogs when exposure, history and clinical presentation indicate a risk of brucellosis.

Keywords: Bayesian latent class analysis; Brucella suis; Competitive ELISA test (C-ELISA); Complement fixation test (CFT); Dogs; Rose Bengal rapid plate agglutination test (RBRPT).