title: Medical students at risk of nosocomial transmission of Mycobacterium tuberculosis.
abstract: METHODS
  University and teaching hospital in Rio de Janeiro, Brazil, a city with a high prevalence of tuberculosis (TB).
  
  
  OBJECTIVE
  To determine whether medical students are at increased risk of nosocomial transmission of Mycobacterium tuberculosis relative to other university students.
  
  
  METHODS
  A cross-sectional study of medical and chemical engineering students in different levels of their training programmes. Information about socio-demographic characteristics, BCG vaccination history, and potential exposures to TB were obtained using a standardised questionnaire. Tuberculin skin testing (TST) was used to determine the prevalence of infection with TB.
  
  
  RESULTS
  Medical students have an increasing prevalence of TST positivity as they advance in their training programme to increasing levels of study (4.6%, 7.8%, 16.2%, respectively, P < 0.001), but chemical engineering students do not (4.2%, 4.3%, 4.4%, respectively, P = 0.913). The risks are greatest during the years of clinical training, when medical students have increased contact with patients.
  
  
  CONCLUSIONS
  Medical students in this setting may be at increased risk of M. tuberculosis infection, relative to chemical engineering students. A programme of routine tuberculin skin testing is needed, combined with interventions to reduce the risk of nosocomial transmission in the workplace.
authors.affiliation: Hospital Universitário Clementino Fraga Filho, Universidade Federal do Rio de Janeiro (HUCFF/UFRJ), Departamento de Clínica Médica, Brazil. vaniasilva@alternex.com.br
authors.forename: V M
authors.initials: VM
authors.lastname: Silva
authors.forename: A J
authors.initials: AJ
authors.lastname: Cunha
authors.forename: J R
authors.initials: JR
authors.lastname: Oliveira
authors.forename: M M
authors.initials: MM
authors.lastname: Figueira
authors.forename: Z B
authors.initials: ZB
authors.lastname: Nunes
authors.forename: K
authors.initials: K
authors.lastname: DeRiemer
authors.forename: A L
authors.initials: AL
authors.lastname: Kritski
mesh_terms: D000328:Adult; D001938:Brazil / Q000453:epidemiology; D002616:Chemical Engineering; D016001:Confidence Intervals; D003428:Cross Infection / Q000453:epidemiology*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D015994:Incidence; D017758:Infectious Disease Transmission, Patient-to-Professional / Q000706:statistics & numerical data*; D016015:Logistic Models; D008297:Male; D016017:Odds Ratio; D012307:Risk Factors; D013337:Students, Medical; D011795:Surveys and Questionnaires; D014376:Tuberculosis / Q000453:epidemiology* / Q000635:transmission*