Microbiology Fundamentals 2nd Edition by Jennifer Bunn,Marjorie Kelly Cowan

Exercise 1

C A S E F I L E

Puzzle in the Valley
Working as a newly graduated radiology technologist in a rural hospital in California, I encountered a case that would prove to be a challenge for everyone involved. The patient was a male migrant farm worker in his mid-30s who presented to the ER with common flulike symptoms: fever, chills, weakness, cough, muscular aches and pains, and headache. He also had a painful red rash on his lower legs.
It was summertime, so influenza was unlikely. The emergency room physician believed that the patient likely had pneumonia, but she found the rash puzzling. She asked me to obtain a chest X ray. I performed anterior-posterior and lateral views of the chest, which revealed two nodules approximately 2 cm in size in the patient's left upper lobe. The physician stated that the nodules were consistent with pneumonia, but the possibility of cancer could not be ruled out. The patient's age and the fact that he was a nonsmoker, however, made a diagnosis of lung cancer much less likely than pneumonia.
The patient was admitted to the hospital for IV antibiotic treatment. Before the antibiotic therapy was started, a sputum sample was collected and sent to a larger center for culture and sensitivity (C S) testing. Despite IV fluids, rest, and broad-spectrum antibiotics targeting both gram-positive and gram-negative bacteria, the patient showed no improvement. After receiving the C S report, I understood why the intravenous antibiotics were not working: The patient had a fungal infection, not a bacterial infection as first suspected. I notified the physician, who immediately started the patient on amphotericin B, a potent antifungal medication that would properly treat the patient's case of coccidioidomycosis.
• How might the patient have contracted this infection?
• Why did the initial antibiotic therapy fail to improve the patient's symptoms?