A 42-year-old man presents to the emergency department with a five-day history of fever, fatigue, cough, and shortness of breath. He initially had mild flu-like symptoms, including a sore throat and muscle aches, but his condition worsened over the past two days, with increasing difficulty breathing. He has no significant medical history but works in a crowded office environment. He reports that a colleague recently tested positive for COVID-19.

On examination, his temperature is 38.2°C (100.8°F), respiratory rate is 24 breaths per minute, and oxygen saturation is 91% of room air. Auscultation of his lungs reveals bilateral crackles. A nasopharyngeal swab is sent for RT-PCR testing, which confirms infection with SARS-CoV-2. A chest X-ray shows patchy infiltrates consistent with viral pneumonia.

The patient is admitted for close monitoring and supportive care. He receives supplemental oxygen, antipyretics for fever, and intravenous fluids. Over the next week, his respiratory symptoms gradually improve, and he is discharged with instructions for home isolation and follow-up. He fully recovers within three weeks.