| Sumario: | Introduction: <i>Coxiella burnetii</i> (<i>C. burnetii</i>)-infected livestock and wildlife have been epidemiologically linked to human Q fever outbreaks. Despite this growing zoonotic threat, knowledge of coxiellosis in wild animals remains limited, and studies to understand their epidemiologic role are needed. In <i>C. burnetii</i>-endemic areas, ticks have been reported to harbor and spread <i>C. burnetii</i> and may serve as indicators of risk of infection in wild animal habitats. Therefore, the aim of this study was to compare molecular techniques for detecting <i>C. burnetii</i> DNA in ticks.
Methods: In total, 169 ticks from wild animals and cattle in wildlife conservancies in northern Kenya were screened for <i>C. burnetii</i> DNA using a conventional PCR (cPCR) and two field-friendly techniques: Biomeme’s <i>C. burnetii</i> qPCR Go-strips (Biomeme) and a new <i>C. burnetii</i> PCR high-resolution melt (PCR-HRM) analysis assay. Results were evaluated, in the absence of a gold standard test, using Bayesian latent class analysis (BLCA) to characterize the proportion of <i>C. burnetii</i> positive ticks and estimate sensitivity (Se) and specificity (Sp) of the three tests.
Results: The final BLCA model included main effects and estimated that PCR-HRM had the highest Se (86%; 95% credible interval: 56–99%), followed by the Biomeme (Se = 57%; 95% credible interval: 34–90%), with the estimated Se of the cPCR being the lowest (24%, 95% credible interval: 10–47%). Specificity estimates for all three assays ranged from 94 to 98%. Based on the model, an estimated 16% of ticks had <i>C. burnetii</i> DNA present.
Discussion: These results reflect the endemicity of <i>C. burnetii</i> in northern Kenya and show the promise of the PCR-HRM assay for <i>C. burnetii</i> surveillance in ticks. Further studies using ticks and wild animal samples will enhance understanding of the epidemiological role of ticks in Q fever.
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