Cryptococcosis

Cryptococcosis 

Cryptococcosis is a disease caused by the yeast-like fungus, Cryptococcosis neoformans. The fungus is found frequently in the environment, particularly in pigeon droppings, nesting places, and soil, especially if it is contaminated with pigeon feces. It has also been associated with certain species of eucalyptus trees. Therefore, exposure to the fungus is common and it is believed that humans have a high natural resistance to infection. People who have disorders of immunity have less resistance and are more susceptible to developing the disease. Naturally acquired cryptococcosis occurs in humans and in animals although there is no evidence of transmission from animals to humans. Cryptococcal meningitis, if untreated, is fatal within weeks to months.

Symptoms

The infection may spread to the brain in people who have a weakened immune system. Neurological (brain) symptoms start slowly. Most people have swelling and irritation of the brain and spinal cord when they are diagnosed. Symptoms of brain infection may include:

• Fever and headache
• Neck stiffness
• Nausea and vomiting
• Blurred vision or double vision
• Confusion
• The infection can also affect the lungs and other organs. Lung symptoms may include:
• Difficulty in breathing
• Cough
• Chest pain

Other symptoms may include:

• Bone pain or tenderness of the breastbone
• Fatigue
• Skin rash, including pinpoint red spots (petechiae), ulcers, or other skin lesions
• Sweating, unusual, excessive at night
• Swollen glands
• Unintentional weight loss

People with a healthy immune system may have no symptoms at all.

Diagnosis 

The following tests are used to diagnose Cryptococcosis:

• The fungal burden can be determined by CSF, blood, and urine cultures.
• Cryptococcal antigen titres (which can be measured in CSF and/or serum), this is a better indicator of fungal burden and outcome.
• Blood tests: FBC, renal, and liver function tests (this can help to detect other illnesses and to monitor drug toxicities, eg amphotericin B can lead to anemia).
• Radiology: this partly depends on the site of infection, eg CXR in pulmonary disease and brain imaging in meningitis/meningoencephalitis (generally MRI scan is better than a CT scan).
• Other investigations: there may be specific to the site of infection, e.g. bronchoalveolar lavage in pulmonary cryptococcosis, liver biopsy.

General Rating Formula for Mycotic Lung Disease (diagnostic codes 6834 through 6839):