A case of disseminated BCG infection in a daughter of Italian immigrants in Switzerland

Bacillus Calmette-Guérin (BCG) is a vaccine against tuberculosis and contains a live, attenuated strain of Mycobacterium bovis as its essential constituent. Being a live, attenuated strain with potential pathogenicity, BCG can cause different complications, both near the inoculation site and through blood dissemination, especially in patients with immunodeficiency. IFN-γR1 deficiency is an autosomal recessively inherited immunodeficiency characterized by predisposition to infections with intracellular pathogens, in particular mycobacteria. We report a rare case of chronic osteomyelitis lasting 30 years due to BCG in a woman with IFN-γR1 deficiency who had previous clinical history of multi-organ BCGitis. Diagnosis of chronic osteomyelitis was confirmed by an 18-fluorine fluorodeoxyglucose positron emission tomography combined with CT scan (18F-FDG PET/CT). In children with a history of BCG vaccination and chronic unexplained infections, a clinical suspicion of BCG-related disease must arise, and a reason of immunodeficiency should be sought.