Assessing Q fever in a representative sample from the United States population: identification of a potential occupational hazard.

Q fever has been associated with exposure to domesticated livestock and the agricultural industry. However large population-based studies examining the relationship are lacking. This report sought to describe the association between Coxiella burnetii infection and participation in agricultural work in the 2003-2004 National Health and Nutrition Examination Survey. Adjusted logistic regression analysis showed that agricultural workers were six times more likely to have antibody evidence of C. burnetii infection than those employed in other occupations (odds ratio 6·5, 95% confidence interval 1·7-25·3). These findings suggest that agricultural workers may experience greater C. burnetii infection and emphasize an important need for more detailed study of people engaged in this work.