[A tuberculosis epidemic in one kindergarten].

In a routine PPD skin test among 1st grade pupils in 4 elementary schools, Fukushima prefecture in April 1989, the number of pupils that showed strongly positive was unusually high. Moreover, 2 tuberculosis cases were detected among them. Since those children graduated the same kindergarten, and one of 6 kindergarten teachers had been complaining cough and hoarseness for about 3 to 5 months before being diagnosed as a smear positive patient in the contact survey, she was suspected to be the source of infection. Meanwhile, she had been treated for common cold and chronic bronchitis in several clinics, therefore, the main cause of this epidemic was due to the doctor's delay in detecting the case. With the discovery of 2 additional cases in the contact survey of the kindergarten, there were 5 cases altogether including the index cases. Three of 4 children's cases had been vaccinated with BCG. If the children who showed strong reaction to tuberculin and eventually treated prophylactically with isoniazid were assumed the infected, the rate of development of disease among the infected was 13.6 to 27.3%. Usually, lymph node enlargement of the hilum is said not to be observed among vaccinated, though slightly, it was evident among the cases in this epidemic.