Bacillus Calmette-Gu�rin (BCG) Vaccine-Induced Disease in Healthy Infants: Identification of BCG Gene from Formalin-Fixed Paraffin-Embedded Tissue

Background: Bacillus Calmette-Guérin (BCG) vaccineinduced systemic complication is rare but localized skin lesion develops in the site of inoculation in healthy infants.

Methods: In this report, we described three cases of BCG vaccineinduced skin lesions in healthy immunocompetent infants and a method of identification of BCG gene by polymerase chain reaction (PCR) form fresh frozen of formalin-fixed and paraffinembedded tissue samples.

Results: These cases had a history of BCG vaccination but no family history of tuberculosis and no contact with patients of tuberculosis. Two cases developed cutaneous granuloma in the axilla of ipsilateral side of BCG inoculation. Another case showed granulomatous osteomyelitis of the left 6th rib. Histological examination demonstrated typical pathologic findings for epithelioid granuloma with caseation necrosis, indicating mycobacterium infection. PCR analysis from fresh frozen or formalin-fixed paraffin-embedded tissue rapidly confirmed the infection of Mycobacterium bovis BCG but not M. tuberculosis.

Conclusion: BCG infection should be considered even in healthy infants with a history of BCG vaccination and histology of epithelioid granuloma with caseation necrosis. In such cases, BCG gene identification by PCR would be useful even from formalin-fixed and paraffin embedded tissue samples.