Human Q fever outbreak investigation and management in six European countries: a One Health compendium of practices and recommendations

BACKGROUND: Q fever is a zoonotic disease caused by Coxiella burnetii, with domestic ruminants serving as the main reservoir. Infected animals can shed large quantities of the pathogen into the environment after normal parturition or abortion, enabling airborne transmission to humans and potentially triggering outbreaks of variable scale. Effective outbreak management requires the rapid identification of all related cases, tracing of infection source(s), and implementing proportionate control measures that protect human health while considering animal health and ecosystem integrity.

OBJECTIVES: This report aimed to review and compare human Q fever outbreak management protocols across several European countries, identify areas of convergence, highlight operational challenges, and outline key gaps in diagnostic tools, source investigations, and cross-sector coordination. It also seeks to propose research priorities and recommendations to support more coordinated One Health preparedness and response.

SOURCES: The analysis was conducted within the European Union-funded Q‑Net‑Assess project, involving partners from Belgium, France, Germany, Spain, The Netherlands, and the United Kingdom. Information was drawn from national procedures, guideline documents, and operational experiences shared by researchers and experts affiliated with academic, public health, veterinary, and reference laboratories.

CONTENT: This report describes practices related to outbreak detection, notification, case investigation, identification of sources, and implementation of control measures across countries. It maps key differences in national protocols, highlighting variability in diagnostic approaches, environmental sampling, molecular typing, and cross-sector coordination. The synthesis identifies both shared methodological elements and structural limitations that affect timely and effective outbreak management.

IMPLICATIONS: Findings underscore the need for more harmonized and integrated Q fever outbreak management across Europe. The report outlines research priorities and provides recommendations aimed at strengthening diagnostic capacity, enhancing environmental and molecular investigation tools, and improving One Health collaboration. These insights have potential relevance for other airborne zoonotic diseases.