[Tuberculin skin test reaction of health-care workers exposed to tuberculosis infection].
OBJECTIVE
The objective of this study was to describe tuberculin skin test (TST) of health-care workers who had had contacts with a tuberculosis patient and to investigate whether the distributions of the size of TST were different by sputum-smear status of index cases and medical procedures done to the patient.


METHODS
Health-care workers who were exposed to tuberculosis infection through contact with patients before diagnosis of tuberculosis were included in this study. Index cases had pulmonary tuberculosis with positive sputum smear and were registered at Sapporo Public Health Office from April 2001 to March 2002. Subjects without past history of BCG (bacilli Calmette-Guerin) vaccinacion were excluded, and final study subjects were 415 (52 male and 363 female, mean age 29.1 years).


METHODS
Characteristics of index cases and contact status were obtained from the registration cards of tuberculosis cases at Sapporo Public Health Office. Subjects were divided into two or more categories by the characteristics of index cases and the contact status. Distributions of TST of the subjects in different categories were compared.


RESULTS
Contacts with patients received tracheal aspiration showed significantly larger TST reaction than contacts with patients not receiving tracheal aspiration. Among contacts with patients showing minimum to moderately positive sputum-smear, TST reaction was significantly larger in contacts with patients received tracheal aspiration (mean diameter of erythema 35.8 mm) than those not receiving tracheal aspiration (24.8 mm). In contrast, among contacts with patients of severely positive sputum-smear, TST reaction was not significantly different between contacts of patients received tracheal aspiration (35.3 mm) and not receiving tracheal aspiration (33.1 mm).


CONCLUSIONS
TST was significantly stronger in contacts with a tuberculosis patient received tracheal aspiration, which indicates medical procedures such as tracheal aspiration increases the risk of tuberculosis infection in health-care workers.
Tsukishima
Eri
E
Sapporo Public Health Office, Hokkaido, Japan. eri.tsukishima@city.sapporo.jp
Mitsuhashi
Yuu
Y
Takase
Aiko
A
D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D017758:Infectious Disease Transmission, Patient-to-Professional; D007442:Intubation, Intratracheal / Q000009:adverse effects; D007564:Japan / Q000453:epidemiology; D008297:Male; D016273:Occupational Exposure; D012306:Risk; D013396:Suction / Q000009:adverse effects; D014374:Tuberculin Test / Q000706:statistics & numerical data*; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis / Q000453:epidemiology / Q000635:transmission*