Cryptococcosis
Cryptococcosis is a rare fungal infection.Cryptococcosis caused by inhaling the fungus Cryptococcus neoformans. Cryptococcus neoformans is an encapsulated round to oval yeastlike fungus measuring six microns. A characteristic polysaccharide capsule of variable thickness surrounds these yeasts. In its natural enviroment the capsule is thinner and the yeast smaller, while thicker capsules tend to be found from infected tissues. The polysaccharide capsule, the phenoloxidase enzyme of Cryptococcus neoformans , and the organism's ability to grow at 37°C, are its major virulence factors It is present around the world, but infection was relatively rare until the aids epidemic began. The fungus sometimes infects people with Hodgkin's disease or sarcoidosis and those who are on long-term corticosteroid treatment. Cryptococcosis mainly occurs in the tissues covering the brain and spinal cord , resulting in meningitis; in the lungs; and on the skin. Other organs are sometimes involved. the fungus usually shows a predilection for the central nervous system, however skin, bones and other visceral organs may also become involved. Although Cryptococcus neoformans is regarded as the principle pathogenic species, Cryptococcus albidus and Cryptococcus laurentii have on occasion also been implicated in human infection. Cryptococcus neoformans has two varieties- Neoformans and gattii . The species has four serotypes based on antigenic specificity of the capsular polysaccharide. The Cryptococcus neoformans var neoformans is the most common variety in the United States and other temperate climates throughout the world and.It is found in aged pigeon droppings. Cryptococcus neoformans var gattii develops in tropical and subtropical climates and is not associated with birds, but it grows in the litter around certain species of eucalyptus trees. there are major varieties with differing biological, ecological, and epidemiological characteristics For many years.
In humans Cryptococcus neoformans affects immunocompromised hosts predominantly and is the commonest cause of fungal meningitis. Worldwide ten percentage of patients with AIDS are affected. In patients with AIDS, skin manifestations represent the second most common site of disseminated cryptococcosis. A causes most cryptococcal infections in patients who are immunocompromised. In contrast, the distribution of cryptococcosis due to Cryptococcus gattii is geographically restricted, non-immunocompromised hosts are usually affected, large mass lesions in lung and/or brain are characteristic and morbidity from neurological disease is high. Cryptococcus has been reported from the respiratory tract, especially sputum and from skin in healthy people as a result of normal environmental exposure. cryptococcosis may occur in some patients when primary infections may not readily resolve in some patients, leading to a more chronic pneumonia progressing slowly over several years. Patients may become pyrexic and have an accompanying cough, however many pulmonary lesions are often asymptomatic, especially when chronic granulomas are formed. Chronic pulmonary cryptococcosis also increases the risk of dissemination to the central nervous system. Osseous cryptococcosis occurs in up to 10% of disseminated cases and may involve bony prominences, cranial bones and vertebrae. The lesions are lytic without periosteal reaction and symptoms of dull pain on movement are reported. Occasional cases of arthritis have also been reported, mostly involving the knee joint. Cryptococcus neoformans is often isolated from urine of patients with disseminated infection. Occasionally, signs of pyelonephritis or prostatitis may be observed
Causes of Cryptococcosis
Common causes of Cryptococcosis
- Infection.
- Spread throughout the body.
- Tumor-like masses.
- Spinal cord.
- Cerebellum.
Symptoms of Cryptococcosis
Common symptoms of Cryptococcosis
- Intracranial mass.
- Include headache.
- Drowsiness.
- Nausea.
- Vomiting.
- Mental changes.
- Slurred speech.
- Double vision.
- Unsteadiness of gait.
- Fever.
- Headache.
- Loss of appetite.
- Bruises.
- Cough.
Treatment of Cryptococcosis
Common Treatment of Cryptococcosis
- Hematogenous spread to the central nervous system has a severe and often fatal course, especially in debilitated patients.
- Patients with mild to moderate severity culture-positive non-CNS infections can be treated with fluconazole or itraconazole for 6 to 12 months
- Discontinuation of Antifungal Therapy for Cryptococcosis after Immunologic Response to Antiretroviral Therapy.
- AIDS patients with either pulmonary should be treated as mentioned above.Until recently, It was recommended that AIDS patients be placed on a lifelong maintenance antifungal regimen, with fluconazole.
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