Problem: A 22-year-old male visited physician office for the evaluation of a cough and fever. His illness began several days ago with low-grade fever, headache and myalgias, slowly worsened and now has a persistent cough. History suggestive of returned from a vacation two weeks ago. He took multiple over-the-counter cold and cough medications but no relief. He has a previous history of asthma from when he was one year old. On examination, he is coughing frequently, his temperature is 38.1°C (100.5°F), pulse is 90/min, and respiratory rate is 22/min. His pharynx is red and inflamed. Head and neck exams are normal. His lung exam showed scattered rhonchi throughout lung fields. All other systemic examinations are normal. What are the differentials? What investigations will help with the diagnosis? Explain the abnormal investigations seen in this patient? Most likely final diagnosis?