Tolpinrud AStenos JChaber A-LDevlin JMHerbert CPas ADunowska MStevenson MAFirestone SMBarrs, VR2024-01-192024-07-252022-06-022024-01-192024-07-252022-07Tolpinrud A, Stenos J, Chaber A-L, Devlin JM, Herbert C, Pas A, Dunowska M, Stevenson MA, Firestone SM. (2022). Validation of an Indirect Immunofluorescence Assay and Commercial Q Fever Enzyme-Linked Immunosorbent Assay for Use in Macropods.. J Clin Microbiol. 60. 7. (pp. e0023622-).0095-1137https://mro.massey.ac.nz/handle/10179/70742Kangaroos are considered to be an important reservoir of Q fever in Australia, although there is limited knowledge on the true prevalence and distribution of coxiellosis in Australian macropod populations. Serological tests serve as useful surveillance tools, but formal test validation is needed to be able to estimate true seroprevalence rates, and few tests have been validated to screen wildlife species for Q fever. In this study, we modified and optimized a phase-specific indirect immunofluorescence assay (IFA) for the detection of IgG antibodies against Coxiella burnetii in macropod sera. The assay was validated against the commercially available ID Screen Q fever indirect multispecies enzyme-linked immunosorbent assay (ELISA) kit (IDVet, Grabels, France) to estimate the diagnostic sensitivity and specificity of each assay, using Bayesian latent class analysis. A direct comparison of the two tests was performed by testing 303 serum samples from 10 macropod populations from the east coast of Australia and New Zealand. The analysis indicated that the IFA had relatively high diagnostic sensitivity (97.6% [95% credible interval [CrI], 88.0 to 99.9]) and diagnostic specificity (98.5% [95% CrI, 94.4 to 99.9]). In comparison, the ELISA had relatively poor diagnostic sensitivity (42.1% [95% CrI, 33.7 to 50.8]) and similar diagnostic specificity (99.2% [95% CrI, 96.4 to 100]) using the cutoff values recommended by the manufacturer. The estimated true seroprevalence of C. burnetii exposure in the macropod populations included in this study ranged from 0% in New Zealand and Victoria, Australia, up to 94.2% in one population from New South Wales, Australia.(c) 2022 The Author/sCC BY 4.0https://creativecommons.org/licenses/by/4.0/Bayesian latent class modelsCoxiella burnetiiELISAQ feverenzyme-linked immunosorbent assayimmunofluorescence assaymacropodssensitivityspecificitytest validationAntibodies, BacterialBayes TheoremCoxiella burnetiiEnzyme-Linked Immunosorbent AssayFluorescent Antibody Technique, IndirectHumansQ FeverSeroepidemiologic StudiesVictoriaJournal article10.1128/jcm.00236-221098-660Xjournal-articlee0023622-https://www.ncbi.nlm.nih.gov/pubmed/35652310e0023622