Cryptococcosis

Cryptococcosis is a potentially fatal fungal infection of mainly the lungs, presenting as a pneumonia, and in the brain, where it appears as a meningitis. Coughing, difficulty breathing, chest pain and fever are seen when the lungs are infected. When the brain is infected, symptoms include headache, fever, neck pain, nausea and vomiting, light sensitivity and confusion or changes in behavior. It can also affect other parts of the body including skin, where it may appear as several fluid-filled nodules with dead tissue. It is caused by the fungi Cryptococcus neoformans or less commonly Cryptococcus gattii, and is acquired by breathing in the spores from the air. These fungi are found globally in soil, decaying wood, pigeon droppings, and in the hollows of some species of trees. Whereas C. neoformans generally infects people with HIV/AIDS and those on immunosuppressant drugs and does not usually affect fit and healthy people, C. gattii (found in some parts of Canada and the US) does. Once breathed in, the dried yeast cells colonize the lungs, where they are either cleared by immune cells, lie dormant, or cause infection and spread. Diagnosis is by isolating Cryptococcus from a sample of affected tissue or direct observation of the fungus by using staining of body fluids. It can be cultured from a cerebrospinal fluid, sputum, and skin biopsy. Characteristic neuroimaging findings include dilated Virchow-Robin spaces, the 'dirty CSF sign', hydrocephalus, cryptococcomas and hazy brain base sign. Many of these findings are non-specific, but the presence of basal meningeal enhancement is significant as it is associated with the future development of cerebral infarct. Treatment is with fluconazole or amphotericin B. Data from 2009 estimated that of the almost one million cases of cryptococcal meningitis that occurred worldwide annually, 700,000 occurred in sub-Saharan Africa, and 600,000 per year died....