The Centers for Disease Control and Prevention (CDC) recommends annual screening for Mycobacterium tuberculosis infection using the tuberculin skin test (TST) for individuals working in hospitals with 200 or more inpatient beds that have at least 6 documented cases of active tuberculosis (TB) per year. The cost of annual TB screening programs is significant, but the cost per individual with TST conversion is unknown. Therefore, we evaluated the annual TB screening program at the Johns Hopkins Hospital and Medical School to determine (1) the proportion of individuals with TST conversion among individuals in the annual TB screening program with patient care exposure at the Johns Hopkins Hospital and Medical School, (2) which employment and demographic factors are associated with TST conversion, (3) the prevalence of active TB disease among those with TST conversion, and (4) the annual cost of subsequent screening of individuals with initial negative TST results and the screening cost per individual with TST conversion.
TST results were reviewed for individuals participating in the annual TB screening program during the previous 4 years (2007–2010) at the Johns Hopkins Hospital and Medical School, which has experienced an average of 12 documented cases of active TB per year. TST was performed before employment and then annually for healthcare providers according to CDC guidelines and the manufacturer's directions. Individuals in the testing program included anyone who had patient contact, such as physicians, nurses, technologists, students, phlebotomists, nutritionists, pharmacists, and clerks. All initial testing was 2-step testing if the individual was initially reactive.