490. Characteristics and evaluation outcomes of immigrants with notifications of latent tuberculosis infection (B2 LTBI) ? California
Session: Poster Abstract Session: Public Health
Thursday, October 3, 2013
Room: The Moscone Center: Poster Hall C
  • Lowenthal_poster_IDSA.pdf (710.2 kB)
  • Background:

    Immigrants resettling permanently in the U.S. are screened for tuberculosis (TB) to prevent importation of active TB. Since 2007, immigration applicants 2-14 years of age with a tuberculin skin test (TST) ≥10 mm and an otherwise negative evaluation for TB are assigned a B2 latent TB infection (LTBI) classification and recommended for domestic evaluation by local health jurisdictions according to Centers for Disease Control and Prevention instructions. We examined the characteristics and outcome of domestic evaluation of immigrants who arrived in California with a B2 classification.


    Data from the Electronic Disease Notification system for immigrants who entered California during 10/1/08 –12/31/12 with a B2 classification were analyzed. Arrivers were categorized by their final TB class on domestic evaluation as defined by the American Thoracic Society. TB case occurrence was determined by matching immigrant arrivers with B2 classification to the California TB registry using a deterministic algorithm.


    There were 11,208 arrivers to California with B2 notifications. Arriver country of origin included the Philippines (54%), Mexico (26%), China (8%), Vietnam (6%), and other (7%). The proportion of arrivers by age category (years) was: 0-4 (11%), 5-9 (31%), 10-14 (53%), ≥15 (5%). Among arrivers, 6614 (59%) were evaluated for TB. 4497 (68%) had repeat testing and 2013 (45%) of these had LTBI on domestic evaluation. Among arrivers with repeat testing, 3352 (75%) had an interferon gamma release assay (IGRA), and of these 782 (23%) were IGRA positive. The proportion of arrivers with negative IGRA decreased with increasing age: 0-4 (85%), 5-9 (80%), 10-14 (70%), ≥15 (65%); and was higher among arrivers from China (89%) and the Philippines (82%), and lower among arrivers from Mexico (50%). Of the 6614 arrivers evaluated, 3027 (46%) received a chest radiograph, and 6 (0.1%) were reported as active TB cases.


    Our findings indicate that very few B2 arrivers had active TB disease and the majority who underwent repeat TB testing in California were found to be negative for LTBI. Inclusion of IGRA in the pre-immigration TB screening process might reduce the workload and cost of B2 evaluations in California.

    Phil Lowenthal, M.P.H., Tuberculosis Control Branch, California Department of Public Health, Richmond, CA


    P. Lowenthal, None

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