Assessing the risk of tuberculosis infection among healthcare workers: the Melbourne Mantoux Study. Melbourne Mantoux Study Group.
OBJECTIVE
To determine the potential prevalence of nosocomial infection with Mycobacterium tuberculosis among hospital employees in teaching hospitals in Melbourne.


METHODS
Cross-sectional survey of positive tuberculin skin test (Mantoux) responses among employees in 14 public hospitals in Melbourne, January 1996 to April 1999.


METHODS
All consenting employees in participating hospitals (4,070 healthcare and 4,298 non-healthcare workers; participation rates, 13%-66%).


METHODS
Prevalence of positive responses to tuberculin skin tests among healthcare and non-healthcare workers and association with employee and hospital characteristics.


RESULTS
Healthcare workers were significantly more likely to have a positive tuberculin response than non-healthcare workers (19.3% versus 13.7%; odds ratio, 1.5; 95% CI, 1.3-1.7; P<0.001). Multivariable analysis revealed that age, country of birth (high versus low tuberculosis [TB] prevalence), history of BCG (bacille Calmette-Guérin) vaccination, years since last BCG, occupation (healthcare versus non-healthcare worker) and years of hospital employment were all significantly associated with a positive response. Rates of positive responses among employees varied greatly between hospitals (6%-35%). These differences were not explained by employee characteristics, hospital TB patient load (number of admissions or bed-days) or percentage of hospital patients from countries with high TB prevalence. The hospital with the highest rate of positive responses was notable for its lack of negative-pressure isolation rooms for TB patients.


CONCLUSIONS
Positive tuberculin responses are relatively common among hospital employees in Melbourne, with rates varying between hospitals and being higher among healthcare than non-healthcare workers. Employee characteristics, such as age, country of birth and past BCG status, explain little of this variation. More emphasis on TB infection control measures and regular staff screening may be needed.
Stuart
R L
RL
Department of Infectious Diseases and Clinical Epidemiology, Monash Medical Centre, Melbourne, VIC. rhonda.stuart@med.monash.edu.au
Bennett
N J
NJ
Forbes
A B
AB
Grayson
M L
ML
D000293:Adolescent; D000328:Adult; D000368:Aged; D003430:Cross-Sectional Studies; D005260:Female; D006779:Hospitals, Public; D006784:Hospitals, Teaching; D006801:Humans; D017053:Infection Control; D017758:Infectious Disease Transmission, Patient-to-Professional / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009784:Occupational Diseases / Q000175:diagnosis / Q000453:epidemiology*; D010564:Personnel, Hospital / Q000706:statistics & numerical data*; D011159:Population Surveillance; D015995:Prevalence; D012044:Regression Analysis; D018570:Risk Assessment; D012307:Risk Factors; D012882:Skin Tests; D011795:Surveys and Questionnaires; D013997:Time Factors; D014373:Tuberculin; D014376:Tuberculosis / Q000175:diagnosis / Q000453:epidemiology* / Q000635:transmission; D014739:Victoria / Q000453:epidemiology
D014373:Tuberculin