A survey of latent tuberculosis infection among laboratory healthcare workers in New York City.
OBJECTIVE
To determine the prevalence of positive tuberculin skin tests (TSTs), incidence of TST conversion, risk factors for positive TSTs, and history of active TB among HCWs in microbiology laboratories in New York City.


METHODS
Two-year survey from May 1999 to June 2001.


METHODS
Nineteen microbiology laboratories.


RESULTS
During the first year, interviews were conducted with 345 laboratory HCWs (mean, 18 HCWs per site; range, 2 to 51) to assess the prevalence of positive TSTs, but 3 (1%) could not recall their result and were excluded from further analyses. The mean age of the remaining 342 HCWs was 48 years; 68% (n = 233) were female, 54% (n = 183) received bacille Calmette-Guerin (BCG) vaccination, and 71% (n = 244) were foreign born. The prevalence of a positive TST was 57% (n = 196), but only 20% (n = 39) of the HCWs received isoniazid. The incidence of TST conversion in the second year of the study was 1% (1 of 108). Multivariate analysis identified age (odds ratio [OR] per year, 1.05; 95% confidence interval [CI95], 1.02-1.08), foreign birth (OR, 3.80; CI95, 1.98-7.28), BCG immunization (OR, 4.89; CI95, 2.72-8.80), and employment in a mycobacteriology laboratory (OR, 2.14; CI95, 1.25-3.68) as risk factors for a positive TST. Only one HCW had been treated for active TB.


CONCLUSIONS
The prevalence of positive TSTs was high among laboratory HCWs, but the TST conversion rate was low. Higher rates of treatment for latent TB infection are desirable.
Garber
Elizabeth
E
TB study group, Division of Infectious Diseases, Department of Pediatrics, College of Physicians & Surgeons, Columbia University, New York, New York 10032, USA.
San Gabriel
Pablo
P
Lambert
Lauren
L
Saiman
Lisa
L
D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D015994:Incidence; D007407:Interviews as Topic; D007757:Laboratory Infection / Q000175:diagnosis / Q000453:epidemiology* / Q000382:microbiology; D008297:Male; D017056:Medical Laboratory Personnel; D008829:Microbiology; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification / Q000472:pathogenicity; D009519:New York City / Q000453:epidemiology; D016273:Occupational Exposure; D015995:Prevalence; D012307:Risk Factors; D014374:Tuberculin Test / Q000706:statistics & numerical data*; D014376:Tuberculosis / Q000175:diagnosis / Q000453:epidemiology*; D000078329:Workforce