Q. A 30-year-old homeless male presents to the clinic. The patient complains of fever, cough, and hemoptysis over the last 3 days. His past medical history is unremarkable. The patient admits to smoking marijuana and injecting heroin over the past 2 years. On examination his blood pressure is 120/80 mmHg, heart rate 110/min, respiration rate 16/min, and temperature is 101°F. Chest examination shows a systolic murmur that increases on inspiration. A chest x-ray is shows lesions in peripheral lung fields, which are round and scattered. An ECG is also performed and reveals sinus tachycardia. What is the most likely diagnosis?