21st June 2024

A patient with a known diagnosis of advanced HIV and has not yet commenced antiretroviral therapy

A patient with a known diagnosis of advanced HIV and has not yet commenced antiretroviral therapy is transferred to a Scottish hospital with fever, neck stiffness and headache developing over four weeks. A CT scan is performed, which does not suggest raised intracranial pressure. Following consultation with neurosurgery, a lumbar puncture is performed which shows an elevated opening pressure of 30 cm H2O, a normal white cell count and an elevated protein at 800 mg/L. India ink staining shows large white islands against a black background.

What is the most likely causative pathogen causing this CNS infection?

Select the SINGLE most appropriate option from the list below. Select ONE option only.