Microbiology and Immunology

Fungi and parasites Practice Questions

20 free Fungi and parasites practice questions for the USMLE Step 1, each with the correct answer and a detailed explanation. Open any question below, or take the full set as an interactive quiz.

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All Fungi and parasites questions

20 questions
  1. Q1. A patient presents with pneumonia after traveling to the Ohio River Valley. Chest imaging shows calcified granulomas. Which organism is the most likely cause?
  2. Q2. A diabetic patient presents with necrotic facial lesions and black eschar in the nasal cavity. Broad, non-septate hyphae are seen. Which fungus is responsible?
  3. Q3. A patient with HIV develops meningitis. CSF shows encapsulated yeasts that are India ink–positive. What is the most likely pathogen?
  4. Q4. A 45-year-old farmer in Arizona develops fever, cough, and erythema nodosum. Spherules containing endospores are found in tissue biopsy. What is the diagnosis?
  5. Q5. A patient has a slowly spreading ulcer on the hand after a thorn injury. Cigar-shaped budding yeasts are found. What is the organism?
  6. Q6. A patient presents with tinea corporis. Which fungus is the most likely cause?
  7. Q7. A patient presents with hypopigmented patches on the skin. A KOH prep reveals “spaghetti and meatballs” appearance. Which organism is responsible?
  8. Q8. A bone marrow transplant recipient develops pulmonary infiltrates. “Acute angle” septate hyphae are seen invading blood vessels. What is the organism?
  9. Q9. A patient presents with pneumonia after visiting caves with bat droppings in Latin America. Large yeast cells with a “captain’s wheel” appearance are seen. Wha…
  10. Q10. A patient develops thrush and vaginal infections after prolonged antibiotic use. Which organism is the most likely cause?
  11. Q11. A patient develops liver abscesses after traveling to India. Stool microscopy shows trophozoites with ingested RBCs. What is the organism?
  12. Q12. A camper develops foul-smelling, watery diarrhea. Stool exam shows pear-shaped organisms with flagella. What is the most likely cause?
  13. Q13. A patient with AIDS has chronic diarrhea. Acid-fast staining of stool shows oocysts. Which organism is responsible?
  14. Q14. A child develops perianal itching at night. Tape test shows oval eggs. What parasite is responsible?
  15. Q15. A patient infected with undercooked pork develops seizures. Brain imaging reveals cystic lesions. What parasite is the most likely cause?
  16. Q16. A patient develops hematuria from chronic parasitic infection. The eggs have terminal spines. What is the organism?
  17. Q17. A patient presents with a hydatid cyst in the liver after exposure to sheep and dogs. What is the causative organism?
  18. Q18. A patient develops myalgias and periorbital edema after eating undercooked wild game. What parasite is the most likely cause?
  19. Q19. A cat owner develops chorioretinitis. The pathogen is transmitted by oocysts in cat feces. What organism is responsible?
  20. Q20. A traveler to Africa develops cyclical fever, anemia, and splenomegaly. Blood smear shows ring forms in RBCs. What organism is responsible?