Cryptococcus neoformans are basidiomycetous yeasts which occur worldwide and are isolated readily from dry pigeon feces. Although it is found in pigeons, they are not infected by the yeasts. It is the leading cause of fungal meningitis. It is also an important cause of morbidity and mortality to those who have undergone transplant procedures and those with active AIDS infection.
Infection starts by inhalation of yeast cells, which in nature are dry, small encapsulated and easily aerosolized. The primary pulmonary infection may have influenza like symptoms. In immunocompromised patients, the yeast multiplies and spreads to other parts of the body and greatly affects the central nervous system causing cryptococcal meningoencephalitis.
Cryptococcus neoformans causes the disease Cryptococcosis. It is a chronic infection of C. neoformans in which the lungs is the main site of infection but spreads to the central nervous system leading to cryptococcal meningoencephalitis. Symptoms experienced by the patient include headache, neck stiffness and disorientation. To some, they may experience fever lasting for weeks with mental status changes. Headache is experienced due to increase in cerebrospinal fluid and protein in the brain.
Specimens used in diagnosis include the spinal fluid, tissue, exudates, sputum, urine and blood. The serologic procedure used is based on the identification of antigens of C. neoformans and not its antibody.
Combination therapy of amphotericin B and 5-fluorocytosine is effective in the treatment of Cryptococcosis. Fluconazole is also used which offers an excellent penetration of the central nervous system. Patients with AIDS infection that are treated with antiretroviral therapy have lower chances of having cryptococcosis and if ever they are infected, they have much better prognosis than those without antiretroviral therapy.
Patients who are immunocompromised should be constantly reminded into not having birds specifically pigeons as their pet at home. Explain to them that this pet poses a great risk for his health and predisposes him to have cryptococcosis. If this is not possible then at least situate the patient away from where the pet bird is kept. Always clean the birds house removing its feces and make sure that these feces are not scattered everywhere near the patient. Decontamination of bird feces is done with the use of alkali.
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