Epidemiology & Prevention USMLE Step 1 Practice Question
A college student develops meningococcal meningitis and lives in a house with 12 roommates. Two roommates were already febrile and symptomatic on the same day as the index patient and are considered co-primary cases. During the next week, 3 of the remaining roommates develop meningococcal disease despite prophylaxis delays. Which of the following is the secondary attack rate in this household?
Answer choices
- A2/10
- B3/10Correct answer
- C3/12
- D5/12
- E5/10
- F4/12
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