Which of the following organism is the most common cause of acute meningitis in an AIDS patient?

Oppounistic infections of the CNS generally occur in HIV infected patients with CD4 counts below 200. Most common organism that causes acute meningitis in an AIDS patients is Cyptococcus neoformans. Cryptococcus neoformans is an encapsulated budding yeast that is found worldwide in soil and on dried pigeon dung. Infections are acquired by inhalation. In the lung, the infection may remain localized, heal, or disseminate. Progressive lung disease and dissemination occur in cases of cellular immunodeficiency. Ref: Current Medical Diagnosis and Treatment, 2012, Chapter 36