Hepatitis D virus

A 47-year-old man presents to the emergency department with altered mental status. He was found unconscious in an alley by a bystander who called paramedics to the scene. Upon arrival in the emergency department, the patient is mumbling but is unable to report his medical history. Chart review demonstrates a history of intravenous drug use and chronic hepatitis B infection. Temperature is 36 °C (96.8°F), pulse is 112/min, respirations are 10/min, blood pressure is 100/53 mmHg, and oxygen saturation is 95% on room air. Physical examination demonstrates jaundice, track marks on the upper extremities, as well as diffuse ecchymosis. The patient is appropriately resuscitated, and the following laboratory results are seen:

This patient's clinical presentation is most consistent with infection with which of the following pathogens?