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.