- Pathogen: Cryptococcus neoformans var gattii AKA. Cryptococcus gatti, no known generic name.
- Type: Fungus, yeast
- Name of the disease caused by the pathogen: Cryptococcal Disease
- Symptoms of infection: Symptoms depend on the site of infection.A respiratory infection can be asymptomatic airway colonization to respitory distress. When the pathogen infects an organ there is little . When tissues are infected the disease is often described as papules, or ulcers. When the CNS is infected symptoms of headaches, confusion, and other mental issues manifest. nausea and vomiting often occur because of the increased intracranial pressures.
- Primary host (s): Humans but often found in the air and soil surrounding rotting eucalyptus wood.
- Other host(s): Can also been found in cats, dogs, parrots, llamas, and even dolphins.
- Route of transmission: inhalation of dissociated cells or basidiospores.
- Ro: varies on the climate. In more humid years the fungi is more prevelant. There is no known person to person transmission therefore Ro is <1.
- Prevalence: It is thought that over a million people a year are innoculated with the yeast cells but only about twenty or thirty people become seriously ill. Although it is known up to 15% of AIDS patents develop some form of cryptococcal disease and these patents account for 80-90% of all cryptococcal infections.
- Generation Time: Not known but symptoms of the infection can manifest within 2 weeks of inoculation.
- Mortality Rate: Can be up to 14%. The mortality of the disease is also dependant on the location of the infection. Infection of the CNS is much higher than skin and respiratory infections. Treatment is often an antifungal medication and on occasion surgery for removal of the growth.
- Morbidity Rate: Depends on the location of the infection, This disease is not known for it’s morbidity.
- Is it preventable? How?: Yes, the disease is preventable with a proper immune system. If one is immunio comprimised it is possible to move to a location further inland or into a colder climate or wear a proper respirator.
- Does the disease trigger long lasting immunity?: No, unfortunately if the fungus infects an organism their immune system is already not functioning properly. If a person is lucky enough to survive and cure an infection they are likely to become infected again if exposed.
- When was the pathogen first described and is there evidence that it was around much earlier than that?: What is the economic impact of the disease?: The fungi was first described in a paper written by Busse in 1894 when the pathogen was found in the tibia of a patent. In 1970 that pathogen was discribed as a variant and in 2001 it became a species. The economic impact is undocumented but seeing domesticated farm animals have been known to contract the disease and diagnosis is often found after death. In humans the disease is often expensive to diagnose and treat. As the infection becomes more prevalent the cost associated with treatment is going down.
- The coolest thing about the disease (in your opinion): Cryptococcus gattii seems to be able to survive in a large diversity of locations and hosts. This lack of specificity is the most interesting to me.
Citations for the information include:
Bartlett, Karen, “Questions and Answers About Cryptococcal Disease”, revised 3-25-2005, BC center for disease control.
King, John, “Cryptococcsis”, emedicine journal, http://emedicine.medscape.com/article/215354-overview
updated Oct 30 2009
Sorrell, T.C., Cryptococcus neoformans var. Gatti, Medical Mycology 2001, 39, 155-168.