Increased tuberculosis risk among immigrants arriving in California with abnormal domestic chest radiographs.

Setting: Tuberculosis (TB) cases in California, USA, occur predominantly among foreign-born persons, many of whom have abnormal chest radiographs (CXRs) on overseas medical examination. These persons are recommended for follow-up TB evaluation upon arrival in the United States.

Objective: To estimate the increased TB risk associated with abnormal vs. normal domestic CXRs among individuals arriving with abnormal overseas CXRs.

Design: Cox regression analyses of 35 633 foreign-born persons aged 15 years who arrived in California during 1999-2012 with abnormal overseas CXRs and were free of imported active TB. Domestic CXRs were conducted during post-arrival evaluation. Subsequent cases through 2014 were identified from California's TB registry.

Results: A total of 121 (0.3%) arrivers developed TB disease. Progression rates were respectively 63.6 (95%CI 50.8-76.4) and 25.4 (95% CI 15.7-35.2) cases/100 000 person-years among persons with abnormal and normal domestic CXRs. Relative to arrivers with normal domestic CXRs, those with abnormal domestic CXRs had an elevated disease risk during the first 4 years after immigration; this increased risk was greatest during the first year (hazard ratio 2.9, 95%CI 1.8-4.8).

Conclusion: Among arrivers with abnormal overseas CXRs, those with abnormal CXRs upon domestic evaluation have an elevated disease risk and represent an important target group for preventive treatment.