Incidence of infectious diseases in children with Mycobacterium tuberculosis in Japan

BackgroundIn Japan, the universal Bacillus Calmette-Guerin (BCG) immunization program for infants aged < 13 months remains in effect. Since 2005, the BCG vaccination history has been required to be reported, in addition to the clinical and treatment status of childhood TB, through a notification system and made available as epidemiological data. MethodsTo understand the epidemiology of childhood tuberculosis (TB) in Japan under the 2013 Bacillus Calmette-Guerin (BCG) immunization program modification in Japan, we performed descriptive analysis on the national surveillance data. ResultsThe median percentage of annual vaccination coverage for infants aged <13 months was 97.0% during the observed period (2007-2022). The age at which the majority of infants received their vaccinations was 3 months before 2013 and 5 months since 2013.During the follow-up period, the number of childhood TB notifications and annual incidence decreased by approximately 60% and 40%, respectively. The analysis revealed correlation between childhood TB and both age and BCG vaccination history, while the impact of the 2013 BCG immunization program modification was not statistically significant. ConclusionThese findings, derived from the national surveillance data in Japan, serve as a valuable resource for future research, offering insights into the efficacy of BCG and the impact of BCG policies.