BCG VACCINATION TO PREVENT TUBERCULOSIS IN HEALTH-CARE WORKERS - A DECISION-ANALYSIS

Objective. To perform a decision analysis to determine the optimal str ategy to prevent tuberculosis (TB) in health care workers with negativ e tuberculin skin tests. Methods. We used a Markov model to study the occurrence of events each year and compared BCG vaccination to annual tuberculin testing plus isoniazid (INH) preventive therapy for those w ho become skin-test positive, The outcome measures studied were the nu mber of cases and deaths from TB and BCG and/or INH adverse reactions over 10 years. Results. Annual tuberculin testing decreases the number of TB cases by 9% and BCG vaccination decreases the number by 49%, re lative to no prevention intervention. BCG vaccination results in fewer deaths than annual tuberculin testing if the workplace incidence of M ycobacterium tuberculosis infection is greater than 0.06%, BCG vaccina tion effectiveness exceeds 3%, or the rate of fatal BCG adverse reacti ons is less than 15 times the rate reported in the literature. Conclus ions. BCG vaccination results in less morbidity and mortality than ann ual tuberculin skin testing for health care workers in workplaces with documented TB transmission despite comprehensive infection control po licies and procedures. Current policy on the prevention of TB among he alth care workers should be reconsidered. (C) 1997 Academic Press.