Effectiveness of a nosocomial tuberculosis control program at an urban teaching hospital.

STUDY OBJECTIVE

To assess the effectiveness of a nosocomial tuberculosis (TB) program at an urban teaching hospital.

DESIGN

Retrospective review.

SETTING

An urban teaching hospital, the University of California, San Diego Medical Center (UCSD), which cares for 25 to 30 culture-proven pulmonary TB cases (>80% of which are smear-positive) per year.

STUDY POPULATION

Health-care workers.

MEASUREMENTS

(1) Purified protein derivative (PPD) conversion rates. (2) Cases of active TB among health-care workers. (3) Compliance rates with isoniazid (INH) preventive therapy.

RESULTS

The UCSD program was evaluated for the years 1993 to 1995. The PPD conversion rate among established employees was 0.6%. Of 556 employees who had an exposure, 494 (88.8%) were compliant with follow-up. Three hundred thirty-seven were skin-tested (the other 157 already had a known PPD >10 mm). Only 2 of 337 (0.6%) converted. One case of active TB, unrelated to any documented hospital exposure, was discovered in 3 years among approximately 5,000 employees per year (follow-up for convertors, 18 to 54 months). Only 48.4% of eligible employees completed at least 6 months of INH preventive therapy.

CONCLUSIONS

UCSD's TB control measures appear to be effective in the prevention of nosocomial transmission of TB. Despite poor compliance with INH preventive therapy, cases of active TB among health-care workers were rare.