Increased production of interleukin-10 by human blood monocytes stimulated with Mycobacterium avium-intracellulare complex

BACKGROUND: Overseas screening of immigrants and refugees applying for a visa to the United States identifies foreign-born individuals who are at high risk for tuberculosis (TB) or who have active TB. The system's effectiveness relies on further medical evaluation and follow-up of foreign-born individuals after their arrival in the United States. METHODS: Retrospective cohort study of 893 immigrants and refugees who arrived in the United States from July 1, 1992, through December 31, 1993, with a destination of San Francisco, Calif, and a referral for further medical evaluation. MAIN OUTCOME MEASURES: Time to report to the local health department after arrival and the yield of active and preventable cases of TB from follow-up medical evaluations. RESULTS: Median time from arrival in the United States to seeking care in San Francisco was 9 days (range, 1-920 days). Of 745 immigrants and refugees (83.4%) who sought further medical evaluation, 51 (6.9%) had active TB and 296 (39.7%) were candidates for preventive therapy. Being a refugee was an independent predictor of failure to seek further medical evaluation in the United States. Class B-1 disease status based on overseas TB screening (odds ratio, 3.5; 95% confidence interval, 2.0-6.2) and being from mainland China (odds ratio, 4.4; 95% confidence interval, 1.9-9.9) were independent predictors of TB diagnosed in San Francisco. CONCLUSIONS: Timely, adequate medical evaluation and follow-up care of immigrants and refugees has a relatively high yield and should be a high priority for TB prevention and control programs.