Your new experience awaits. Try the new design now and help us make it even better

ORIGINAL RESEARCH article

Front. Epidemiol.

Sec. Infectious Disease Epidemiology

Exposure of feral swine to Coxiella burnetii overlaps with human Q fever incidence in California

Provisionally accepted
Ian A. McMillanIan A. McMillan1*Samuel J. GolonSamuel J. Golon2Michael H NorrisMichael H Norris1Gregory A. FranckowiakGregory A. Franckowiak3James M. GrinoldsJames M. Grinolds3Richard A BowenRichard A Bowen2Vienna BrownVienna Brown3Bradley BorleeBradley Borlee2*
  • 1University of Hawaii at Manoa, Honolulu, United States
  • 2Colorado State University, Fort Collins, United States
  • 3USDA-National Feral Swine Damage Management Program, Fort Collins, United States

The final, formatted version of the article will be published soon.

Select one of your emails

You have multiple emails registered with Frontiers:

Notify me on publication

Please enter your email address:

If you already have an account, please login

You don't have a Frontiers account ? You can register here

Coxiella burnetii is a zoonotic pathogen that causes Q fever in humans. There are many known reservoirs of C. burnetii, including cattle, sheep, and goats with an expanding list of potential reservoirs including birds, reptiles, ticks and additional mammalian species, such as swine. Feral swine are a highly invasive species in the United States with significant populations and a broad geographic distribution. The role of feral swine in the transmission and spread of C. burnetii is poorly understood, although a recent report identified overlap between feral swine seroprevalence and human Q fever incidence in Texas. California accounts for a large proportion of human Q fever cases in the United States and in this study we characterized the seroprevalence of C. burnetii in feral swine populations in the state. Feral swine showed seropositivity rates up to 1.64% indicating some level of exposure and the possibility that they may serve as a reservoir for disease transmission and spread. Overlap with human Q fever incidence was identified in the central region of California. Although this study does not directly link feral swine to human infection, it identified spatial overlap between feral swine seroprevalence and human Q fever incidence in the state of California, possibly due to the presence of ruminants as the principal reservoirs of C. burnetii. The environmental stability and low infectious dose of C. burnetii, coupled with the geographic overlap between feral swine seroprevalence and human Q fever incidence suggests that feral swine may contribute to zoonotic disease transmission and spread.

Keywords: Feral swine, Coxiella burnetii, Q Fever, seroprevalence, California

Received: 26 Aug 2025; Accepted: 05 Dec 2025.

Copyright: © 2025 McMillan, Golon, Norris, Franckowiak, Grinolds, Bowen, Brown and Borlee. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence:
Ian A. McMillan
Bradley Borlee

Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.

Supplementary Material