An 18-Year-Old Iowan Dirt Bike Racer, Who Raced for the First

Multiple Choice

An 18-year-old Iowan dirt bike racer, who raced for the first time in the desert southwest 3 weeks ago, presents in September with cough, malaise, low-grade fever, myalgias, and chest pain. Rales are heard and respiratory infiltrates are noted on radiograph. Sputum stained with calcofluor white and viewed on an ultraviolet microscope shows large blue-white fluorescing spherical structures (with a wall) and with numerous small round cells inside. What is the most likely causative agent?

A) Candida albicans
B) Coccidioides immitis
C) Histoplasma capsulatum
D) Influenza virus type A
E) Mycoplasma pneumoniae
F) Streptococcus pneumoniae