Culture‑proven disseminated Mycobacterium Bovis infection (BCG‑Osis) following intravesical BCG immunotherapy in a patient with bladder carcinoma‑in‑situ: ‘Case report’.

We are reporting a case of culture-proven disseminated Mycobacterium Bovis infection (BCG-Osis), involving lung, bone-marrow and urinary tract, after intravesical Bacillus Calmette–Guérin (BCG) immunotherapy for bladder carcinoma-in-situ. A 71-year-gentleman presented with fever shortly after intravesical BCG instillation. He was initially treated for presumed Urinary Tract Infection, but negative urine culture and persistent fever prompted us to consider alternative diagnoses. Empirical treatment for BCG-Osis was commenced after initial negative workup including blood culture, echocardiography, computed tomography (CT) Chest, and Kidney-Ureter-Bladder (KUB). However, he remained febrile and leukopenic, so bone-marrow examination was performed along with repeating CT Chest, which revealed non-caseating granulomas and small nonspecific pulmonary nodules, respectively, supporting our provisional diagnosis. Interestingly, Mycobacterium Bovis was finally isolated from one of his urine specimens, confirming our diagnosis.