Objectives: To investigate the rates of latent TB infection (LTBI) in a sample of young people in San Diego County and examine potential predictors of a positive tuberculin skin test (TST).
Methods: Latino and foreign-born students from ten public middle and high schools were invited to screenings along with a random 10% sample of all other students. After obtaining parental consent, Mantoux tests were placed (N=2,698) and read (n=2,667 [98.9%]) in 48-72 hours. A positive TST was defined as > or =10 mm induration. The mean age of the sample was 14.34 years (SD=1.81); 50.1% were female (n=1,353); 78.5% were Latino (n=2,108); 35.7% were foreign-born (n=939); and 44.3% were uninsured (n=930).
Results: The positive TST rate for Latinos was 21.8% vs. 5.6% for non-Latinos, p<0.001. Foreign-born Latinos had the highest infection rate (31.3%), followed by foreign-born non-Latinos (20.4%), U.S.-born Latinos (15.4%), and U.S.-born non-Latinos (1.0%), p<0.001. Logistic regression was conducted to determine predictors of TST positivity. Being Latino (odds ratio [OR]=3.27), uninsured (OR=1.60), foreign-born (OR=3.90), and living in the south county region closest to the U.S./Mexico border (OR=2.72) were significant predictors.
Conclusions: Results suggest that Latino youth near the California/Mexico border are at high risk for infection, for remaining undiagnosed, and for being under-treated for LTBI.