Seroprevalence of Q fever in the United States, 2003-2004.
We performed serum testing for IgG antibodies against Coxiella burnetii (phase I and phase II) and analyzed questionnaire data from 4,437 adults > or = 20 years of age who participated in the National Health and Nutrition Examination Survey 2003-2004 survey cycle. National Q fever seroprevalence was determined by enzyme-linked immunosorbent assay and confirmed by using immunofluorescent antibody testing. Overall seroprevalence for Coxiella burnetii was 3.1% (95% confidence interval [CI] = 2.1-4.3%) among 4,437 adults > or = 20 years of age. Coxiella burnetii age-adjusted antibody prevalence was higher for men than for women (3.8%, 95% CI = 2.7-5.2% versus 2.5%, 95% CI = 1.5-3.7%, respectively, P < 0.05). Mexican Americans had a significantly higher antibody prevalence (7.4%, 95% CI = 6.6-8.3%) than either non-Hispanic whites (2.8%, 95% CI = 1.7-4.3%) or non-Hispanic blacks (1.3%, 95% CI = 0.6-2.5%) (P < 0.001). Multivariate analysis showed that the risk for Q fever antibody positivity increased with age and was higher among persons who were foreign-born, male, and living in poverty. These findings indicate that the national seroprevalence of Q fever in the United States is higher than expected on the basis of case numbers reported to the Centers for Disease Control and Prevention from state health departments. Potential differences in risk for exposure by race/ethnicity warrant further study.
Anderson
Alicia D
AD
National Center for Zoonotic, Vector-Borne, and Enteric Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA. aha5@cdc.gov
Kruszon-Moran
Deanna
D
Loftis
Amanda D
AD
McQuillan
Geraldine
G
Nicholson
William L
WL
Priestley
Rachel A
RA
Candee
Amanda J
AJ
Patterson
Nicole E
NE
Massung
Robert F
RF
D000328:Adult; D000368:Aged; D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D016997:Coxiella burnetii / Q000276:immunology; D054242:Emigrants and Immigrants; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011778:Q Fever / Q000453:epidemiology*; D016036:Seroepidemiologic Studies; D012959:Socioeconomic Factors; D013997:Time Factors; D014481:United States / Q000453:epidemiology; D055815:Young Adult
D000907:Antibodies, Bacterial