Unrecognized tuberculosis in a nursing home causing death with spread of tuberculosis to the community

OBJECTIVES: To determine the reason for an increase in tuberculin skin test (TST) conversion in employees in a nursing home and to determine the source case responsible for spread of tuberculosis (TB) in two nursing homes and a hospital in a rural part of Arkansas using molecular and traditional epidemiological methods. DESIGN: TB contact investigation of residents and employees of two nursing homes and a hospital. SETTING: Two nursing homes and a hospital in rural part of Arkansas. PARTICIPANTS: One hundred fifty-seven employees and 117 residents of two nursing homes and 211 employees of a hospital in rural part of Arkansas MEASUREMENTS: Tuberculin skin test. RESULTS: Analysis of room and work assignments of residents and employees who converted their TSTs in Nursing Home A showed that residents and employees in the same wing as the suspect source case were significantly more likely to have converted their TST than residents an employees in other wings (P =.01). A nurse from the local hospital where the suspected source case had been sent developed a tuberculous cervical abscess, and one employee in Nursing Home A developed pulmonary TB, A visitor to Nursing Home A was diagnosed with culture-positive pulmonary TB 2 years later. Genotyping of the Mycobacterium tuberculosis isolates from the four secondary cases showed identical patterns. CONCLUSION: Molecular and traditional epidemiological studies revealed an outbreak of TB that began in a nursing home and spread to a second nursing home, a local hospital, and the community.