Mycobacterium bovis (Bacille Calmette-Guérin) bacteremia in immunocompetent neonates following vaccination.

We describe four cases of Mycobacterium tuberculosis complex bacteremia diagnosed in immunocompetent neonates, who presented with high fever and/or jaundice within 72h after Bacille Calmette-Guérin (BCG) vaccination. All neonates were hospitalized, and none received anti-mycobacterial therapy. All recovered completely and remain healthy 2–3.5 years later. Genotyping of one available isolate identified the pathogen as Mycobacterium bovis BCG. The similar clinical presentations and close temporal association between BCG vaccination and illness suggest that all four neonates likely had BCG bacteremia. BCG bacteremia shortly following vaccination among healthy neonates has not been previously described and merits further study to determine its frequency and clinical significance.