La. Cocchiarella et al., POSITIVE TUBERCULIN SKIN-TEST REACTIONS AMONG HOUSE STAFF AT A PUBLICHOSPITAL IN THE ERA OF RESURGENT TUBERCULOSIS, American journal of infection control, 24(1), 1996, pp. 7-12
Background: The number and significance of tuberculin skin test reacti
ons were compared with self-reported baseline values among house staff
working in a public hospital. High-risk medical specialties, location
s, and infection control practices were examined. Methods: House staff
interviews, tuberculin skin test applications, review of employee hea
lth service records, and environmental monitoring of high-risk areas w
ere performed. Results: Among house staff self-reported as having nega
tive tuberculin skin test status, 46.2% (95% CI 27.0% to 65.4%) of int
ernal medicine house staff, compared with 4.8% (95% CI 4.3% to 13.9%)
of house staff from other areas (p < 0.005), had positive results on a
repeat tuberculin skin testing before graduation. These differences w
ere not entirely explained by the use of surgical masks, year of train
ing, or previous vaccination with bacille Calmette-Guerin. Most skin t
est reactions (69%) occurred among house staff who had not been vaccin
ated with bacille Calmette-Guerin. Increased skin reactivity probably
represented excess conversions from unprotected exposure. Tuberculosis
transmission was facilitated by delays in diagnosis, inadequate isola
tion facilities, and suboptimal ventilation. House staff did not compl
y with recommended tuberculosis surveillance because of time constrain
ts, fear, and misunderstandings about tuberculin skin test interpretat
ions in light of previous bacille Calmette-Guerin vaccination. Conclus
ions: House staff in high-exposure settings with suboptimal environmen
tal controls are at increased risk for tuberculosis infection. Partici
pation in surveillance programs can be increased by enlisting the part
icipation and advocacy of respected medical colleagues, screening hous
e staff differentially according to exposure and job classifications,
and more accurately interpreting subsequent test results from baseline
two-step testing.