[Osteitis as a complication of BCG vaccination]

To investigate the incidence and increasing tendency of osteitis after BCG vaccination and, in addition, its clinical features, diagnostic methods and results of treatment.

22 cases of Japanese children who received BCG vaccination between 1998 and 2007 and developed osteitis, and were reported in medical journals or meetings.

Incidence was very low, 0.2 per 100,000 vaccinations, and an increasing tendency was not seen after 2005, when the vaccination in Japan was limited to below 6 months after birth. However, it might be necessary to follow for much longer period. About 73% of cases of osteitis were seen from 9 to 18 months after receiving the vaccination. The bones of the extremities were commonly affected. Radiography usually showed the defect and cavity formation of the affected bone and often abscess around the lesion. Definitive diagnosis was made by the detection of BCG from the pus or biopsied materials. Recently, multiplex PCR method have been utilized and proved to be a rapid and reliable diagnostic method. Tuberculin reaction was positive, but QFT was negative in all tested cases; QFT will be available for the differential diagnosis of BCG and tuberculous infection. Only 2 patients had multiple lesions, and they had partial interferon-gamma receptor 1 deficiency. Immunodeficiency might have some relationship to the development of osteitis after BCG vaccination. The treatment using INH and RFP was very effective and the outcome was favorable; most of the patients were cured after 6 to 12 months chemotherapy without any complications. However, there is the possibility of defects occurring in the bone and restriction of the articular movement when the diagnosis and treatment are delayed.

BCG osteitis, although rare, should be considered as a possible complication of the BCG vaccination, and early diagnosis and treatment of this complication is necessary.