[Present activity of BCG and LTBI treatment for infants in Japan].

I analyzed the BCG vaccination and treatment of latent tuberculosis infection (LTBI) for infants notified in 2008 in Japan. BCG was not recommended and treatment of LTBI was the main activity for prevention of TB in infants from birth to age 2 months. The majority of notified LTBI cases were detected by contact surveys. Out of the estimated number of TB infected (148), only 2 cases were notified based on the outcome of LTBI treatment for 89 infants. When the infants were 3-5 months old, both BCG vaccination and LTBI treatment were implemented. BCG coverage was 61.5-97.7%, and LTBI treatment for non-vaccinated individuals was applied for a larger number of infants (1.04 to 7.82 times as many) than the estimated number of infants infected with TB. The majority of infants were BCG vaccinated when they were 6-11 months old. Although LTBI treatment coverage was low, only 5 cases developed among those receiving BCG vaccination. During 1-2 year, BCG coverage was high and breakdown rates of BCG-vaccinated children were much lower than those of non-vaccinated children. This difference might be due to not only the preventive effect of BCG but also risk difference of TB infection between BCG-vaccinated and BCG non-vaccinated individuals. The number of notified LTBI treatment cases was lower than the estimated number of children infected with TB during 1-2 year. To prevent infant TB, reinforcement of contact surveys to identify LTBI for treatment, improvement of BCG coverage, and attention to BCG non-vaccinated infants older than 6 months might be effective.