Am. J. Respir. Crit. Care Med., Vol 154, No. 4, Oct 1996, 1006-1012.
Tuberculosis infection among health care workers in Montreal
K Schwartzman, V Loo, J Pasztor and D Menzies
Montreal Chest Institute, Royal Victoria Hospital, Montreal, Canada.
We conducted a cross-sectional survey to estimate the prevalence of
tuberculosis infection among health care workers at two downtown Montreal
hospitals. Participants completed questionnaires, then underwent two-step
tuberculin testing. Records of previous tuberculin tests and BCG
vaccinations were reviewed. Charts of all tuberculosis patients admitted in
1992-93 were also reviewed. Air changes and direction of air flow in
patient care areas were measured using tracer gas techniques and smoke
tubes. Of 619 eligible workers, 522 participated (84%). 196 (38%) were
tuberculin reactors; 23 (4%) had documented conversions. Inadequate
ventilation and delays in diagnosis were identified at both hospitals.
Comparing clinical with nonclinical personnel, the adjusted odds of a
significant initial tuberculin reaction were 2.6 (95% confidence interval
1.3, 5.2), of a documented conversion 13.6 (1.4, 132), and of a booster
reaction 0.9 (0.2, 3.6). Initial tuberculin reactivity was associated with
male gender (p = 0.008), BCG vaccination (p = 0.0001), foreign birth (p =
0.007), age (p < 0.0001), and occupation (p = 0.02); conversion with
male gender (p = 0.001) and occupation (p = 0.01); and boosting with older
age (p = 0.02) and BCG vaccination (p = 0.001). Among clinical personnel at
two hospitals, the prevalence of significant tuberculin reactions and of
documented conversions was unexpectedly high.
