Cryptosporidium, or "hidden spore," is a microscopic, protozoan parasite 1/25,000 of an inch in size, capable of causing gastrointestinal disease. It is recognized as one of the 3 most common
Cryptosporidium, or "hidden spore," is a microscopic, protozoan parasite 1/25,000 of an inch in size, capable of causing gastrointestinal disease. It is recognized as one of the 3 most common diarrhea-causing intestinal pathogens in the world. Cryptosporidiosis, the disease caused by the organism, can vary significantly from self-limiting to life-threatening, depending on the immune status of the individual. Persons with greater than 300 CD4 cells/mm3 are more likely to have self-limited disease, while those with fewer than 200 CD4 cells/mm3 almost always have persistent disease. Mortality from cryptosporidiosis approaches 80% in the immunocompromised. The current lack of a cure and standard effective treatment makes avoiding exposure to this pathogen highly desirable.
Transmission of cryptosporidium is by the oral-fecal route and occurs when the oocyst, a small hard-shelled capsule formed during one stage of the parasite's life cycle, is ingested. The oocyst is extremely tenacious, highly resistant to disinfectant and capable of living outside the host for 2-6 months in a moist environment. Symptoms of infection vary, but most commonly include abdominal cramps and diarrhea. Nausea, vomiting, malaise and low-grade fever may also be present. In the presence of HIV infection, cryptosporidiosis can become a protracted disease from which recovery may be difficult.
Recognizing the importance of reducing the risk of exposure to this disease, the Centers for Disease Control and Prevention (CDC) in September 1995 issued prevention guidelines for HIV positive individuals. These include:
* Wash hands with soap and water before eating anything, after touching children in diapers or after touching clothing, bedding or surfaces soiled by someone with diarrhea. Washing hands frequently may be the most important prevention activity. Often overlooked as a source of Cryptosporidium, garden soil may become contaminated by neighborhood pets or by farm animals in rural areas. Wear gloves while gardening and wash hands after gloves are removed. Always wash hands before preparing food. A responsible adult should supervise hand-washing in children.
* Practice safer sex. Cryptosporidium can be found on the skin in the genital area, including thighs and buttocks, of an infected person. It cannot be seen, and an infected person may be asymptomatic; therefore, safer sex practices should be strictly observed. Mouth-to-anal contact can spread cryptosporidiosis, even in the presence of meticulous hygiene. Wash hands after any sexual activity.
* Always wash hands after touching any animal. Farm animals, particularly young ones, should be considered a source of infection. Contact should be followed by careful hand washing. Most house pets are safe. Young puppies or kittens should be examined by a veterinarian for infection. An HIV positive person should avoid cleaning cat litter boxes or disposing of pet stools. If help is not available, gloves should be worn and hands washed after the gloves are removed.
* Wash and or cook all food. If safe water is a concern, wash in water that is known to be Cryptosporidium-free. Peeling fresh fruits and vegetables that will not be cooked reduces the risk of exposure, and some kinds of cooking eliminate the risk. Unless processed food has been contaminated by an infected food handler after processing, it is probably safe. Unpasteurized drinks are not safe. In 1994, 160 cases of cryptosporidiosis were reported among persons who attended an agricultural fair in Maine and drank freshly pressed, unpasteurized ap