A 68-year-old man who emigrated from an eastern European country 30 years ago presents with 5 days of fever, headache, and malaise. He recalls a similar severe febrile illness with a rash during childhood in a louse-infested refugee camp. Examination now shows no rash and he is afebrile between episodes. Blood PCR confirms the suspected diagnosis. What is the mechanism of his current illness?
- A Reactivation of latent Rickettsia prowazekii persisting in lymph nodes and adipose tissue ✓
- B Reinfection with Rickettsia typhi from a new flea exposure
- C Relapse due to incomplete antibiotic treatment of the childhood illness
- D Chronic bacteraemia with Bartonella quintana acquired from the original camp
Correct answer: A. Reactivation of latent Rickettsia prowazekii persisting in lymph nodes and adipose tissue
Explanation
Brill-Zinsser disease is recrudescent epidemic typhus, caused by reactivation of R. prowazekii that persists for decades after the primary attack. It is milder than primary typhus, rash may be absent, and it matters epidemiologically because a louse feeding on such a patient can become infected and start an epidemic. Reinfection with R. typhi causes murine typhus, a different entity, and incomplete therapy does not cause rickettsial relapse.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.