Using Reports of Latent Tuberculosis Infection Among Young Children to Identify Tuberculosis Transmission in New York City, 2006-2012.

The presence of latent tuberculosis infection (LTBI) in young children indicates recent tuberculosis (TB) transmission. We reviewed surveillance reports of children with LTBI to assess whether more follow-up is needed to prevent TB in this high-risk population. Data on all children under 5 years of age who were reported by health-care providers or laboratories to the New York City Department of Health during 2006-2012 were abstracted from the TB surveillance and case management system, and those with LTBI were identified. Potential source cases, defined as any infectious TB case diagnosed in the 2 years before a child was reported and whose residence was within 0.5 miles (0.8 km) of the child's residence, were identified. Neighborhood risk factors for TB transmission were examined. Among 3,511 reports of children under age 5 years, 1,722 (49%) had LTBI. The children were aged 2.9 years, on average, and most (64%) had been born in the United States. A potential source case was identified for 92% of the children; 27 children lived in the same building as a TB patient. Children with potential source cases were more likely to reside in neighborhoods with high TB incidence, poverty, and population density. The high proportion of children born in the United States and the young average age of the cases imply that undetected TB transmission occurred. Monitoring reports could be used to identify places where transmission occurred, and additional investigation is needed to prevent TB disease.