1882. Contact Investigation of Congenital Tuberculosis in a Neonatal Intensive Care Unit in South Korea

BACKGROUND: Congenital tuberculosis (TB) is uncommon and difficult to detect in neonates due to its nonspecific symptoms. We conducted a contact investigation of infants and healthcare workers (HCWs) exposed to a neonate with congenital TB in a neonatal ICU (NICU) in Korea. METHODS: A premature infant born was admitted to NICU on September 16, 2022. On October 24, the infant's mother was diagnosed with miliary TB, and infant’s sputum AFB stain showed 4 positive results. All NICU infants and HCWs during the same period were screened for active pulmonary TB using chest radiography (CXR) immediately. Exposed infants were evaluated with a TST and CXR three months after exposure. Interferon-Gamma Release Assay (IGRA) testing was performed on those with a positive TST or abnormal CXR finding. Prophylactic rifampin was provided to the exposed infants for 3 months, as index had isoniazid-resistant M. tuberculosis infection. Exposed HCWs underwent IGRA testing immediately after exposure (1(st) IGRA) and at 8 to 10 weeks post-exposure (2(nd) IGRA), and CXR was performed 6 months after exposure. RESULTS: Five out of 82 exposed infants had positive TST (≥ 10 mm) results, while all 31 infants who underwent IGRA testing had negative results. All five with positive TST had received BCG vaccination a median 105 days before. Of the 119 exposed HCWs, three had a conversion; two had negative results (on annual IGRA testing performed according to the national TB prevention Act) before exposure and positive at 1(st) IGRA test, and one had negative 1(st) IGRA test then positive 2(nd) IGRA test. None had active TB during 6-month follow-up. [Figure: see text] CONCLUSION: We found that 6% of exposed infants had positive TST results and 0% had positive IGRA, while 2.5% of exposed HCWs had conversion. Considering the possibility of false positive TST results due to prior BCG vaccination, the chance of transmission to the infants would be 0%; otherwise, it would be 6.1%. DISCLOSURES: All Authors: No reported disclosures