Occupational tuberculosis among deputy sheriffs in Connecticut: a risk model of transmission.
OBJECTIVE
The purpose of this study was to identify risk factors for tuberculin skin test conversions among non-infected deputy sheriffs in Connecticut and during an out-break in an urban lock-up.


METHODS
377 tuberculin skin-test negative sheriffs statewide in 1994-1995 and 37 sheriffs in the lock-up in 1995 were screened and questionnaires administered. Cellblock volumetric air flow was measured. The Wells-Riley model of airborne transmission [C = S(1-e-Iqpt/Q)] was applied to the epidemiologic and ventilation data.


RESULTS
Statewide, of 377 sheriffs screened, 22 (5.8%) had positive skin tests. Risk factors included older age (p < .0075) and longer tenure (p < .036). In the lock-up, of 37 sheriffs screened, 4 (10.8%) had positive skin tests. Measured mean outside air flow per occupant (8.0 cfm; S.D. = 2.2) was below design (15 cfm) and recommended (20 cfm) standards. Mathematical modeling estimated that TB transmission would be reduced by 62.5 percent with ventilation at design specifications.


CONCLUSIONS
Inadequate ventilation may increase the risk for occupational transmission of tuberculosis. Since lock-ups do not have the time to conduct inmate TB screenings, supplemental engineering controls may be required.
Cooper-Arnold
K
K
Department of Medicine, University of Connecticut Health Center, Farmington, USA.
Morse
T
T
Hodgson
M
M
Pettigrew
C
C
Wallace
R
R
Clive
J
J
Gasecki
J
J
D000328:Adult; D003237:Connecticut / Q000453:epidemiology; D004196:Disease Outbreaks / Q000517:prevention & control*; D006801:Humans; D008875:Middle Aged; D008954:Models, Biological; D009784:Occupational Diseases / Q000453:epidemiology / Q000517:prevention & control*; D016495:Police / Q000706:statistics & numerical data*; D012306:Risk; D014376:Tuberculosis / Q000453:epidemiology / Q000517:prevention & control / Q000635:transmission*; D014691:Ventilation