title: Reduced importation of tuberculosis after the implementation of an enhanced pre-immigration screening protocol.
abstract: METHODS
  Importation of infectious tuberculosis (TB) threatens TB control in California and the United States.
  
  
  OBJECTIVE
  To assess the effectiveness of an enhanced pre-immigration screening and treatment protocol to prevent the importation of infectious TB.
  
  
  METHODS
  Retrospective analysis of immigrants ≥ 15 years of age with TB suspect classifications who were screened for TB in their countries of origin before (pre-intervention cohort) and after (post-intervention cohort) implementation of enhanced pre-immigration screening. Enhanced pre-immigration screening added sputum cultures to the existing screening system based on sputum smears for persons with abnormal chest radiographs.
  
  
  RESULTS
  The pre- and post-intervention cohorts included respectively 2049 and 1430 immigrants. The occurrence of tuberculosis ≤ 6 months after US arrival in this population decreased following the intervention, from 4.2% (86 cases) to 1.5% (22 cases, P < 0.001). Among pre-intervention cohort cases, 14% were sputum acid-fast bacilli (AFB) smear-positive and 81% were sputum culture-positive for TB, compared with 5% sputum AFB smear-positive (P = 0.46) and 68% sputum culture-positive (P = 0.18) among the post-intervention cohort cases.
  
  
  CONCLUSIONS
  The enhanced pre-immigration screening was associated with a decline in the proportion of immigrants with TB suspect classifications identified with TB within 6 months of arrival in the United States. Continued state and national surveillance is critical to monitor the effectiveness of the revised pre-immigration screening as it is implemented in additional countries.
authors.affiliation: California Department of Public Health, Tuberculosis Control Branch, Richmond, California 94804-6403, USA. phil.lowenthal@cdph.ca.gov
authors.forename: P
authors.initials: P
authors.lastname: Lowenthal
authors.forename: J
authors.initials: J
authors.lastname: Westenhouse
authors.forename: M
authors.initials: M
authors.lastname: Moore
authors.forename: D L
authors.initials: DL
authors.lastname: Posey
authors.forename: J P
authors.initials: JP
authors.lastname: Watt
authors.forename: J
authors.initials: J
authors.lastname: Flood
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002140:California / Q000453:epidemiology; D002487:Centers for Disease Control and Prevention, U.S.; D003140:Communicable Disease Control / Q000379:methods*; D016208:Databases, Factual; D004641:Emigration and Immigration / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000379:methods; D008800:Mexico; D008875:Middle Aged; D010679:Philippines; D011859:Radiography; D012189:Retrospective Studies; D013183:Sputum / Q000382:microbiology*; D014376:Tuberculosis / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000517:prevention & control*; D014481:United States / Q000453:epidemiology; D014744:Vietnam; D055815:Young Adult