title: Risk factors for tuberculosis among health care workers in South India: a nested case-control study.
abstract: OBJECTIVE
  The epidemiology of tuberculosis (TB) among health care workers (HCWs) in India remains under-researched. This study is a nested case-control design assessing the risk factors for acquiring TB among HCWs in India.
  
  
  METHODS
  It is a nested case-control study conducted at a tertiary teaching hospital in India. Cases (n = 101) were HCWs with active TB. Controls (n = 101) were HCWs who did not have TB, randomly selected from the 6,003 subjects employed at the facility. Cases and controls were compared with respect to clinical and demographic variables.
  
  
  RESULTS
  The cases and controls were of similar age. Logistic regression analysis showed that body mass index (BMI) <19 kg/m(2) (odds ratio [OR]: 2.96, 95% confidence interval [CI]: 1.49-5.87), having frequent contact with patients (OR: 2.83, 95% CI: 1.47-5.45) and being employed in medical wards (OR: 12.37, 95% CI: 1.38-110.17) or microbiology laboratories (OR: 5.65, 95% CI: 1.74-18.36) were independently associated with increased risk of acquiring TB.
  
  
  CONCLUSIONS
  HCWs with frequent patient contact and those with BMI <19 kg/m(2) were at high risk of acquiring active TB. Nosocomial transmission of TB was pronounced in locations, such as medical wards and microbiology laboratories. Surveillance of high-risk HCWs and appropriate infrastructure modifications may be important to prevent interpersonal TB transmission in health care facilities.
authors.affiliation: Department of Medicine, Christian Medical College Hospital, Ida Scudder Road, Vellore 632004, Tamil Nadu, India. anoopmatts@gmail.com
authors.forename: Anoop
authors.initials: A
authors.lastname: Mathew
authors.forename: Thambu
authors.initials: T
authors.lastname: David
authors.forename: Kurien
authors.initials: K
authors.lastname: Thomas
authors.forename: P J
authors.initials: PJ
authors.lastname: Kuruvilla
authors.forename: V
authors.initials: V
authors.lastname: Balaji
authors.forename: Mary V
authors.initials: MV
authors.lastname: Jesudason
authors.forename: Prasanna
authors.initials: P
authors.lastname: Samuel
mesh_terms: D000328:Adult; D015992:Body Mass Index; D016022:Case-Control Studies; D003428:Cross Infection / Q000453:epidemiology / Q000209:etiology; D005260:Female; D006784:Hospitals, Teaching; D006801:Humans; D007194:India / Q000453:epidemiology; D017758:Infectious Disease Transmission, Patient-to-Professional / Q000706:statistics & numerical data; D007755:Laboratories, Hospital; D016015:Logistic Models; D008297:Male; D016273:Occupational Exposure / Q000706:statistics & numerical data; D010564:Personnel, Hospital / Q000706:statistics & numerical data; D012307:Risk Factors; D014397:Tuberculosis, Pulmonary / Q000453:epidemiology / Q000209:etiology*; D000078329:Workforce