A Comparison of Three Screening Tests in Detecting the Prevalence of Latent Tuberculosis Infection in Refugees by History of Residence in Refugee Camps

Purpose: The purpose of this study was to examine residence in a refugee camp as a predictor of testing positive for latent tuberculosis infection (LTBI) according to each of three LTBI screening tests. Methods: Data were obtained from a study funded by the Centers of Disease Control and Prevention (CDC) through the Tuberculosis Epidemiologic Studies Consortium. Refugees presenting at Tarrant County Public Health in Fort Worth, Texas, from countries classified by CDC as having a medium or high risk of tuberculosis (TB) were eligible to participate. Participants were interviewed to obtain data on variables associated with LTBI and received three LTBI screening tests: QuantiFERON-TB Gold In-Tube (QFT), T-SPOT TB, and the tuberculin skin test (TST). The results of each screening test were used as the indicator variable for LTBI. Data analysis was conducted for each screening test result independently using logistic regression to adjust for potential confounders including age, gender, birth country, education, income, smoking, alcohol use, history of incarceration, and being a close contact to a TB case. Results: Of the 994 participants, twenty-six percent originated from medium-risk countries, 22% from high-risk countries in Africa, and 52% from high-risk countries in Asia. The odds of having LTBI for those who lived in a refugee camp compared to those who did not differed according to the screening test used, but was not significant for any of the three tests (QFT OR 0.843, 95% CI 0.568–1.252; T-SPOT OR 0.819, 95% CI 0.548–1.226; and TST OR 1.121, 95% CI 0.791–1.590). Conclusions: Among participants in our study, living in a refugee camp conferred no significantly increased risk of LTBI when adjusted for other predictive variables, independent of the type of screening test utilized.