Q. A 22-year-old woman presents to your primary care clinic with a persistent dry cough, low-grade fever, and malaise for the past week. She reports that several of her dormitory mates are experiencing similar symptoms. Her temperature is 100.8°F (38.2°C), pulse is 88 beats per minute, blood pressure is 120/80 mmHg, and respiratory rate is 18 per minute. On physical examination, bilateral lower lung crackles are heard on auscultation, and absence of consolidation signs. Chest X-ray shows an irregular patchy opacities in the left lung. What is the best next step in management?