A recently retired man appears at his doctor's office complaining of difficulty breathing, body aches and fatigue. He is also running a high fever and has a dry cough. He reports having just returned from a trip to the Middle East where he visited several historical sites. Test results are negative for a rapid test for influenza A. No bacteria are visible in a microscopic exam of his sputum. Which of the following is a likely explanation?
◦ primary atypical pneumonia
◦ pertussis
◦ valley fever
◦ coronavirus respiratory syndrome
◦ inhalation anthrax