Incidence of infectious diseases in children with Mycobacterium tuberculosis in Japan, 2007-2022.

The objective of this study was to understand the descriptive epidemiology of childhood tuberculosis (TB) in Japan under the 2013 Bacillus Calmette-Guérin (BCG) immunization program modification. The median percentage of annual vaccination coverage for infants aged <13 months was 97.0 % during follow-up (2007-2022). The age at which most infants received their vaccinations was 3 months before 2013 and 5 months after 2013. During follow-up, the number of childhood TB notifications and annual incidence declined by approximately 60 % and 40 %, respectively. A multivariate-adjusted model analysis was performed by birth year to determine the association between childhood TB and the 2013 BCG immunization program modification. However, childhood TB was associated with age and BCG vaccination history but not with the 2013 BCG immunization program modification. This study represents a valuable resource for future research, elucidating the efficacy of BCG as well as the impact of BCG policies.