Nosocomial exposure to active pulmonary tuberculosis in a neonatal intensive care unit

Abstract

Nosocomial transmission of tuberculosis (TB) in a neonatal intensive care unit (NICU) is a recognized risk. We investigated TB transmission to neonates and health care workers (HCWs) exposed to a nurse with active TB in a NICU. A NICU nurse in a tertiary referral hospital in Seoul, Korea, developed pulmonary TB. The investigation included 108 infants and 75 HCWs. Tuberculin skin test (TST) and chest radiograph were performed at baseline. Isoniazid prophylaxis was started in neonates. After 3 months of prophylaxis, infants underwent repeat TST and chest radiograph. HCWs underwent a second TST after 3 months. Baseline chest radiographs were negative in infants and HCWs. Four (3.7%) of 108 infants screened had a positive TST, including 2 conversions, and received isoniazid for 6-9 months. Among the 59 HCWs screened, 27 (45.8%) had an initial positive TST result, and 6 (10.2%) had a positive TST result at 3 months. Four of the 6 HCWs with TST conversions received isoniazid treatment for 9 months. In the 2-year period after exposure, none of the exposed infants or HCWs developed active TB. In this investigation, 4 (3.7%) of 108 infants exposed to a nurse with active TB developed latent TB infection. They were given isoniazid therapy without any adverse events and did not progress to TB disease in the 2 years after exposure.