Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2018 May 15;18(1):218.
doi: 10.1186/s12879-018-3135-4.

Airborne geographical dispersal of Q fever from livestock holdings to human communities: a systematic review and critical appraisal of evidence

Nicholas J Clark  1 , Ricardo J Soares Magalhães  2   3
Affiliations

Airborne geographical dispersal of Q fever from livestock holdings to human communities: a systematic review and critical appraisal of evidence

Nicholas J Clark et al. BMC Infect Dis. .

Abstract

Background: Q fever is a zoonotic disease caused by Coxiella burnetii. This bacterium survives harsh conditions and attaches to dust, suggesting environmental dispersal is a risk factor for outbreaks. Spatial epidemiology studies collating evidence on Q fever geographical contamination gradients are needed, as human cases without occupational exposure are increasing worldwide.

Methods: We used a systematic literature search to assess the role of distance from ruminant holdings as a risk factor for human Q fever outbreaks. We also collated evidence for other putative drivers of C. burnetii geographical dispersal.

Results: In all documented outbreaks, infective sheep or goats, not cattle, was the likely source. Evidence suggests a prominent role of airborne dispersal; Coxiella burnetii travels up to 18 km on gale force winds. In rural areas, highest infection risk occurs within 5 km of sources. Urban outbreaks generally occur over smaller distances, though evidence on attack rate gradients is limited. Wind speed / direction, spreading of animal products, and stocking density may all contribute to C. burnetii environmental gradients.

Conclusions: Q fever environmental gradients depend on urbanization level, ruminant species, stocking density and wind speed. While more research is needed, evidence suggests that residential exclusion zones around holdings may be inadequate to contain this zoonotic disease, and should be species-specific.

Keywords: Airborne dispersal; Coxiella burnetii; Geographical contamination gradient; Q fever; Spatial epidemiology; Zoonotic disease.

PubMed Disclaimer

Conflict of interest statement

Ethics approval and consent to participate

Not applicable.

Competing interests

RMS declares that he is an editorial board member of BMC Infectious Diseases

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Figures

Fig. 1
Fig. 1
Schematic representation of potential drivers of Coxiella burnetii spatial dispersal from livestock holdings. Green shading indicates potential human transmission pathways. The top section of the figure demonstrates how airborne dispersal and environmental contamination are proposed to contribute to the zoonotic exposure of human communities. This dispersal can be influenced over a range of spatial distances by factors represented in the bottom section of the figure
See this image and copyright information in PMC

References

    1. Orr H, Christensen H, Smyth B, Dance D, Carrington D, Paul I, Stuart J. Case-control study for risk factors for Q fever in Southwest England and Northern Ireland. Eur Surveill. 2006;11(10):260–262. doi: 10.2807/esm.11.10.00655-en. - DOI - PubMed
    1. Roest H-J, van Gelderen B, Dinkla A, Frangoulidis D, van Zijderveld F, Rebel J, van Keulen L. Q fever in pregnant goats: pathogenesis and excretion of Coxiella burnetii. PLoS One. 2012;7(11):e48949. doi: 10.1371/journal.pone.0048949. - DOI - PMC - PubMed
    1. Raoult D, Marrie T, Mege J. Natural history and pathophysiology of Q fever. The Lancet Infect Dis. 2005;5(4):219–226. doi: 10.1016/S1473-3099(05)70052-9. - DOI - PubMed
    1. Vaglia A, Di Fabrizio N, Dal Pra P. Q fever: clinical epidemiological remarks on our case report. Giornale di Malattie Infettive e Parassitarie. 1984;36(12):1343–1345.
    1. Caron F, Meurice JC, Ingrand P, Bourgoin A, Masson P, Roblot P, Patte F. Acute Q fever pneumonia: a review of 80 hospitalized patients. Chest. 1998;114(3):808–813. doi: 10.1378/chest.114.3.808. - DOI - PubMed

Publication types