Background: Extrapulmonary tuberculosis is likely a marker of underlying immune compromise. Our objective was to determine race and sex differences in extrapulmonary tuberculosis risk in order to identify the optimal population in which to assess for host factors associated with extrapulmonary tuberculosis.
Methods: We performed an observational study of all tuberculosis cases reported to the Tennessee Department of Health, January 1, 2000 to December 31, 2006. We compared the incidence of extrapulmonary tuberculosis by race and sex. We also examined risk factors associated with extrapulmonary disease among all persons with tuberculosis.
Results: Extrapulmonary tuberculosis incidence per 100,000 population was 5.93 in black men, 3.21 in black women, 1.01 in non-black men, and 0.58 in non-black women. Among those with tuberculosis, black women were most likely to have extrapulmonary disease (38.6%), followed by black men (28.1%), non-black women (24.6%) and non-black men (21.1%). In multivariate logistic regression among persons with tuberculosis, black women (OR 1.82 (95% CI 1.24-2.65), p = 0.002), black men (OR 1.54 (95% CI 1.13-2.09, p = 0.006), foreign birth (OR 1.55 (95% CI 1.12-2.14), p = 0.009), and HIV infection (OR 1.45 (95% CI 0.99-2.11), p = 0.06) were associated with extrapulmonary tuberculosis.
Conclusions: Black men and black women had the highest incidence of extrapulmonary tuberculosis, and high odds of extrapulmonary disease among persons with tuberculosis. These data suggest that factors in addition to tuberculosis exposure contribute to extrapulmonary tuberculosis risk in blacks.