What is Cryptococcus neoformans?

Cryptococcus neoformans is a fungal organism that can cause disease in immunocompromised hosts, though occasionally people with no apparent immune system problems can also develop cryptoccosis. Its main habitats are debris around pigeon roosts and soil contaminated with decaying pigeon or chicken droppings.

How is Cryptococcus neoformans spread?

It is generally accepted that the organism enters the host by the respiratory route in the form of a dehydrated haploid yeast or as basidiospores. After some time in the lungs, the organism hematogenously spreads to extrapulmonary tissues; since it has a predilection for the brain, infected persons may contract meningoencephalitis. Cryptococcus neoformans does not spread from person to person.

Who is at risk for infection?

Human hosts with impaired immune responses are at higher risk for acquiring most of these fungal infections and for extrapulmonary dissemination of the disease.

Is Cryptococcus neoformans infection serious?

If untreated, cryptococcal meningoencephalitis is 100% fatal, and even when treated with the most effective antifungal drugs, cryptococcal infections can be fatal if the host is immunocompromised.

How can I protect myself?

Accidental parenteral inoculation of cultures or other infectious materials represents a potential hazard to laboratory personnelÑparticularly to those that may be immunocompromised. Bites by experimentally infected mice and manipulations of infectious environmental materials (e.g., pigeon droppings) may also represent a potential hazard to laboratory personnel. Biosafety Level 2 and Animal Biosafety Level 2 practices and facilities are recommended, respectively, for activities with known or potentially infectious clinical, environmental, or culture materials and with experimentally infected animals. The processing of soil or other environmental materials known or likely to contain infectious yeast cells should be conducted in a Class I or II biological safety cabinet. This precaution is also indicated for culture of the perfect or sexual state of the agent.

What are the signs of Cryptococcus neoformans infection?

Cryptococcal infection may cause a pneumonia-like illness, with shortness of breath, coughing and fever. Skin lesions may also occur. Another common form of cryptococcosis is central nervous system infection, such as meningoencephalitis. People with cryptococcal meningoencephalitis are usually immunocompromised. Symptoms may include fever, headache, or change in mental status.

What do I do if an exposure or injury occurs?

Exposure to aerosols, bites or scratches involving animals or injuries from objects contaminated with body fluids from animals require immediate first aid and medical attention. Notify your supervisor! Then, between the hours of 8:00 am and 5:00 pm., call or proceed to Stanford Occupational Health Clinic; 480 Oak Road, Rm B15; 5-5308. After 5:00 pm and before 8:00 am., call or proceed to the Stanford Emergency Room, H126 (in the hospital, next to the cafeteria), 723-2670.

General Questions?
Call the Laboratory Animal Occupational Health Surveillance Program's Health Provider:
Stanford University Occupational Health Center (650) 725-5308
Veterinary Service Center
(650) 723-3876
or Stanford Environmental Health & Safety
(650) 723-0448.

This document provided by:
Laboratory Animal Occupational Health Surveillance Program
Department of Environmental Health and Safety
Stanford University

For more information, or to make comments on this page, please contact the EH&S Biosafety Officer: esegal@stanford.edu

Last modified: Tuesday, April 27, 2010

Helpful websites:
http://www.cdc.gov/ncidod/EID/vol4no1/buchanan.htm
http://www.cdc.gov/nczved/dfbmd/disease_listing/cryptococcus_gi.html