A 32-year-old male, living in a rural community in sub-Saharan Africa, presents to the clinic with a 2-week history of fever, chills, and night sweats. He also reports feeling unusually weak, with difficulty breathing upon exertion and a persistent cough. His symptoms have progressively worsened, and he has noticed swelling in his legs. He has no history of recent travel or known exposure to infectious diseases.

The patient has a history of poorly controlled rheumatic heart disease, diagnosed in childhood, with significant mitral valve regurgitation. He denies recent dental procedures, intravenous drug use, or other invasive procedures. On physical examination, the patient appears ill and febrile, with a temperature of 38.7°C (101.7°F). His heart rate is elevated at 110 beats per minute, and blood pressure is 100/60 mmHg. He has peripheral oedema and a systolic murmur best heard at the apex. Splinter haemorrhages are noted on his fingernails, and small petechial lesions are visible on his palms.

A transthoracic echocardiogram reveals large, irregular masses attached to the mitral valve, consistent with vegetations. Blood cultures are positive for Streptococcus viridans. Based on these findings, the patient is diagnosed with infective endocarditis.

He is started on broad-spectrum intravenous antibiotics and is referred to a cardiologist for further management, which may include valve surgery depending on his response to treatment.