Question 55

Question:

A 26-year-old HIV-positive woman is brought into the emergency room after she is found lying unresponsive in the street. She has no recollection of what had occurred. She reports sensing a smell “like burning hair” and then blacking out. Medical history reveals that she has had a fever and a headache for the past week. An MRI of the brain shows multiple ring-enhancing lesions. Which of the following is the most likely cause of her symptoms?

Correct Answer: E.  Toxoplasma gondii

This patient has likely suffered a seizure due to an infection of Toxoplasma in her brain. The ring-enhancing necrotic lesions in the brain are highly characteristic of toxoplasmosis. HIV-infected and other immunocompromised patients are vulnerable to brain infections by Toxoplasma, which is spread by cysts in meat or cat feces.

The other microorganisms listed are also opportunistic infections that affect HIV-positive patients, but they do not cause ring-enhancing brain lesions.
A non-infectious cause of ring-enhancing brain lesions in AIDS patients is B cell lymphoma of the brain.