SHEA-CDC TB survey, Part II: Efficacy of TB infection control programs at member hospitals, 1992. Society for Healthcare Epidemiology of America.

OBJECTIVE

To assess the efficacy of current Mycobacterium tuberculosis control measures.

DESIGN

Voluntary questionnaire to members of the Society for Healthcare Epidemiology of America.

RESULTS

Healthcare worker (HCW) tuberculin skin-test (TST) conversion rates were significantly higher in larger hospitals (> or = 437 beds) (0.9% versus 0.6%; P < 0.05), or in hospitals reporting > or = 6 TB patients in 1992 (1.2% versus 0.6%; P < 0.05). Among larger hospitals or those hospitals surveyed reporting > or = 6 TB patients, those without at least three of the four criteria suggested in the 1990 Centers for Disease Control and Prevention (CDC) TB guidelines for acid-fast bacilli (AFB) isolation (specifically, a single-patient room; negative pressure; and air exhausted directly outside) had significantly higher annual TST conversion rates than those with these criteria (1.8% versus 0.6%; P < 0.05). Respiratory therapist or bronchoscopist TST conversion rates were significantly lower in hospitals compliant with the exhaust criteria (1.2% versus 2.8%; P < 0.05). Regardless of hospital characteristic, HCW TST conversion rates did not differ between hospitals in which HCWs used surgical masks or used disposable particulate respirators.

CONCLUSION

Among larger hospitals or hospitals reporting > or = 6 TB patients per year, failure to comply with the 1990 CDC TB recommendations for AFB isolation room guidelines was associated with higher HCW TST conversion rates. These data suggest that complete implementation of the 1990 CDC TB guidelines would decrease HCWs' risk of nosocomial transmission of TB in larger hospitals or those reporting more TB patients. However, in nonoutbreak situations, disposable particulate respirators or submicron surgical masks may not offer significantly greater protection to HCWs than surgical masks.