Aircraft contact investigations for TB on domestic and inbound flights to the United States

<sec><title>BACKGROUND</title>U.S. Centers for Disease Control and Prevention (CDC) coordinates contact investigations (CIs) for TB exposures on commercial flights when criteria are met. Aircraft CIs are resource-intensive and require collaboration with health departments (HDs). Post-exposure TB assessments are challenging as multiple follow-up visits are needed. Evidence supporting TB transmission on aircraft is limited.</sec><sec><title>METHODS</title>TB aircraft CI outcomes data submitted to CDC by HDs from 24 June 2011 to 31 December 2022 were analysed using descriptive statistics to summarise outcomes, risk factors for prior exposure, timing of diagnosis, and data completeness.</sec><sec><title>RESULTS</title>Of 15,043 contacts identified, final determination of TB status was available for 2,282/15,043 (15%). Of these, 3/2,282 (0.1%) had TB disease and 366/22,282 (16%) had TB infection (TBI). Most (78%) contacts with TB had other exposure risk factors. Ten exhibited conversion on serial testing within 4 months after the flight, indicating recent infection. All contacts with TB disease and 44 with TBI (14% of those with test dates available) were tested before HDs were notified of aircraft exposure.</sec><sec><title>CONCLUSION</title>TB aircraft CIs identified persons with TB disease or TBI; however, most had TB risk factors other than aircraft exposure. The low return of outcomes was a limitation for formulating robust recommendations.</sec>