title: Expanding tuberculosis case detection by screening household contacts.
abstract: OBJECTIVE
  Tuberculosis (TB) case detection remains low in many countries, compromising the efficacy of TB control efforts. Current global TB control policy emphasizes case finding through sputum smear microscopy for patients who self-report to primary health centers. Our objective was to assess the feasibility and yield of a simple active case finding strategy in a high incidence population in northern Lima, Peru.
  
  
  METHODS
  We implemented this pilot strategy in one health center's catchment area. Health workers visited household contacts of new TB case subjects to identify symptomatic individuals and collect sputum for screening. Neighboring households were screened in the same manner. Secondary analyses measured risk of TB by (1) sputum smear status of the index case subject, (2) compliance with testing, and (3) risk factors for disease detected through active contact tracing in contrast to self-report.
  
  
  RESULTS
  The TB prevalence detected through combined active and passive case finding among 1,094 household contacts was 0.91% (914 per 100,000), much higher than with passive case finding alone (0.18%; 183 per 100,000; p=0.02). Among 2,258 neighbors, the combined strategy detected a TB prevalence of 0.22% (221 per 100,000) in contrast to 0.08% (80 per 100,000) detected through passive case finding alone (p=0.25). Risk factors for being diagnosed through active case finding in contrast with self-report included age >55 years (odds ratio [OR]=5.5; 95% confidence interval [CI] 1.2, 22.8) and female gender (OR=3.9; 95% CI 0.99, 22.3).
  
  
  CONCLUSIONS
  Risk of active TB among symptomatic household contacts of active case subjects in this community is very high. Results suggest that contact tracing in such settings may be a powerful means of improving case detection rates for active TB disease.
authors.affiliation: Department of Social Medicine, Harvard Medical School, Boston, MA, USA.
authors.forename: Mercedes C
authors.initials: MC
authors.lastname: Becerra
authors.forename: Iliana F
authors.initials: IF
authors.lastname: Pachao-Torreblanca
authors.forename: Jaime
authors.initials: J
authors.lastname: Bayona
authors.forename: Rosa
authors.initials: R
authors.lastname: Celi
authors.forename: Sonya S
authors.initials: SS
authors.lastname: Shin
authors.forename: Jim Yong
authors.initials: JY
authors.lastname: Kim
authors.forename: Paul E
authors.initials: PE
authors.lastname: Farmer
authors.forename: Megan
authors.initials: M
authors.lastname: Murray
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D003151:Community Health Centers; D016358:Contact Tracing / Q000379:methods*; D005191:Family Characteristics; D005260:Female; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000379:methods / Q000458:organization & administration*; D008875:Middle Aged; D010568:Peru / Q000453:epidemiology; D011635:Public Health Administration; D013183:Sputum / Q000382:microbiology; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis* / Q000453:epidemiology* / Q000517:prevention & control