Double Trouble in the Pericardium: A Rare Co-Infection of Tuberculosis and Tularemia Leading to Cardiac Tamponade.

Cardiac tamponade attributed to co-infection with multiple pathogens is rare. A 40-year-old man who migrated from India 10 years prior with no medical history presented with a progressive dyspnea, night sweats, intermittent fevers, weight loss over a 3-month period, and a cough. An echocardiogram revealed cardiac tamponade and further biopsy revealed necrotizing granulomas with diffuse necrotic lymphadenopathy. Early anchoring bias led to an extensive tuberculosis (TB) workup which was initially negative. However, after broadening the differential, a co-infection of tularemia and latent extrapulmonary TB was identified as the etiology of cardiac tamponade. While tularemia in the setting of immunodepression has been identified as a cause for pericarditis, there is no current literature of a tularemia and TB co-infection causing cardiac tamponade. This case highlights the importance of expanding a differential diagnosis when the presentation does not fit the diagnosis, especially when a delay in management can be consequential.