title: Tuberculosis in household contacts of multidrug-resistant tuberculosis patients.
abstract: METHODS
  The burden of tuberculosis (TB) disease among household contacts of multidrug-resistant TB (MDR-TB) patients is poorly understood and might represent a target for transmission-interrupting interventions.
  
  
  METHODS
  This retrospective cohort study, conducted in Lima, Peru, from  June to September 2008, estimated the incidence of TB disease among household contacts of MDR-TB patients in 358 households.
  
  
  RESULTS
  Of 2112 household contacts in 80 households (22% of households), 108 (5%) developed TB disease during the study, giving an incidence rate of 2360 per 100 000  contact follow-up years for each of the first 3 years after exposure. Drug susceptibility tests (DST) were available for 50 diseased contacts, of whom 36 (80%) had MDR-TB. Forty-two pairs of index-contact DSTs were available, among which the contact had an identical or less resistant phenotype  than the index case in 27 pairs. Multivariate Cox regression demonstrated that male contacts (hazard ratio [HR] 2.8, P < 0.05), with previous TB disease (HR 20.7, P < 0.001) and with associated (non-human immunodeficiency virus) comorbidities (HR 11.2, P < 0.001)  were more likely to develop TB.
  
  
  CONCLUSIONS
  The high percentage of diseased household contacts highlights an opportunity for household-level interventions to prevent transmission, whether or not these cases were all attributable to the index case.
authors.affiliation: The Wellcome Centre for Clinical Tropical Medicine, Imperial College, London, UK. drlouisgrandjean@hotmail.com
authors.forename: L
authors.initials: L
authors.lastname: Grandjean
authors.forename: A
authors.initials: A
authors.lastname: Crossa
authors.forename: R H
authors.initials: RH
authors.lastname: Gilman
authors.forename: C
authors.initials: C
authors.lastname: Herrera
authors.forename: C
authors.initials: C
authors.lastname: Bonilla
authors.forename: O
authors.initials: O
authors.lastname: Jave
authors.forename: J L
authors.initials: JL
authors.lastname: Cabrera
authors.forename: L
authors.initials: L
authors.lastname: Martin
authors.forename: A R
authors.initials: AR
authors.lastname: Escombe
authors.forename: D A J
authors.initials: DA
authors.lastname: Moore
mesh_terms: D000293:Adolescent; D000328:Adult; D000995:Antitubercular Agents / Q000627:therapeutic use*; D015331:Cohort Studies; D017281:Cost of Illness; D005191:Family Characteristics; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D008826:Microbial Sensitivity Tests; D015999:Multivariate Analysis; D010568:Peru / Q000453:epidemiology; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D018088:Tuberculosis, Multidrug-Resistant / Q000188:drug therapy / Q000453:epidemiology*; D055815:Young Adult
chemical_list: D000995:Antitubercular Agents