Q fever: pets, vets and validating tests

Abstract

Q fever is a highly significant worldwide zoonosis caused by thebacteriumCoxiellaburnetii.While infection iscommonly asymptomatic, 40% of primary infections in humans are symptomatic, with serious acute or chronic debilitating illnesses possible, including endocarditis, post-Q fever fatigue syndrome and recrudescent granulomatous lesions in bone or soft tissue. The bacterium itself has a duplicitous lifecycle; a metabolically active form obligately replicates within the macrophage cell lineage while an inactive form has extreme environmental resilience, providing a means to travel to new cells and newhosts. Coupledwith a potentially large, seeminglyasymptomatic reservoirencompassingwild and domestic mammals, birds and arthropods, this bacterium continues to raise important questions about its impact on public health worldwide. Given the targeted and complex nature of testing required to confirm a diagnosis in humans, ongoing vigilance in promptly recognising clinical cases in humans and reappraisal of the potential risks created by animal exposure is required. This article outlines the current evidence on the potential role that cats and dogs might play in transmission of this bacterium and provides a framework for future studies.