Identifying risk factors associated with smear positivity of pulmonary tuberculosis in Kazakhstan

BACKGROUND Sputum smear-positive tuberculosis (TB) patients have a high risk of transmission and are of great epidemiological and infection control significance. Little is known about the smear-positive populations in high TB burden regions, such as Kazakhstan. The objective of this study is to characterize the smear-positive population in Kazakhstan and identify associated modifiable risk factors. METHODS Data on incident TB cases' (identified between April 2012 and March 2014) socio-demographic, risk behavior, and comorbidity characteristics were collected in four regions of Kazakhstan through structured survey and medical record review. We used multivariable logistic regression to determine factors associated with smear positivity. RESULTS Of the total sample, 193 (34.3%) of the 562 study participants tested smear-positive. In the final adjusted multivariable logistic regression model, sex (adjusted odds ratio (aOR) = 2.0, 95% CI:1.3-3.1, p < 0.01), incarceration (aOR = 3.6, 95% CI:1.2-11.1, p = 0.03), alcohol dependence (aOR = 2.6, 95% CI:1.2-5.7, p = 0.02), diabetes (aOR = 5.0, 95% CI:2.4-10.7, p < 0.01), and physician access (aOR = 2.7, 95% CI:1.3-5.5p < 0.01) were associated with smear-positivity. CONCLUSIONS Incarceration, alcohol dependence, diabetes, and physician access are associated with smear positivity among incident TB cases in Kazakhstan. To stem the TB epidemic, screening, treatment and prevention policies should address these factors.