Penny Tompkins

Cryptosporidium  Cryptosporidium is a protozoan parasite in the phylum Apicomplexa  It causes a diarrheal illness called cryptosporidiosis  It affects the intestines of mammals and is usually an acute short-term infection  Immunocompromised individuals, such as AIDS patients, the symptoms are very severe and often fatal  A number of Cryptosporidium infect mammals.  In humans, the main causes of disease are C. parvum and C. hominis (previously C. parvum genotype 1). C. canis, C. felis, C. meleagridis, and C. muris can also cause disease in humans.  Despite not being identified until 1976, it is one of the most common waterborne diseases and is found worldwide

How does infection occur:  Infection with Cryptosporidium parvum typically occurs after a person has swallowed contaminated water, eaten contaminated food, or come into direct contact with contaminated feces. (Falkenstein, 2010).  The parasite is transmitted by environmentally hardy microbial cysts (oocysts) and once ingested, exist in the small intestine causing infection of the intestinal epithelial tissue. Cryptosporidium oocysts

(Marler, 2010) Sporozoites attach to the microvilli of the epithelial cells in the small intestine. After being ingested, the oocysts emerge from cyst in the small intestine. The oocysts contains up to 4 sporozoites that are bow- shaped.

Cryptosporidium  The number of Cryptosporidium oocysts needed to cause human infection is relatively low.  Ingestion of as few as two to ten oocysts can cause illness.  An infectious person can pass millions of oocysts per day in his or her stool.  Even after symptoms resolve, a person can remain infectious for a number of weeks. (Falkenstein, 2010)

Symptoms  The disease can be asymptomatic, cause acute diarrhea, or persistent diarrhea that can last for a few weeks.  Symptoms appear two to ten days after infection, with an average of 7 days. Symptoms may last for up to two weeks, and in some cases up to one month.  As well as watery diarrhea, there is often stomach pains or cramps and a low fever.  Other symptoms include nausea, vomiting, malabsorption, and dehydration.  The individuals who have no symptoms are still infective, and can pass the infection onto others for weeks.

Diagnosis  There are many diagnostic tests for Cryptosporidium.  They include microscopy, staining, and detection of antibodies.  Microscopy can help identify oocysts in the fecal matter.  The ELISA test kit available can detect all species of Cryptosporidium and can be easily run by most veterinary laboratories.

Diagnosis  Cryptosporidium parvum identification of the oocysts with specific stains such as modified acid fast stain.

Microscopic Identification of Cryptosporidium Parvum  Oocysts appear as bright pink to red organisms containing some dark granules and usually have a central clear area. (Khan, 2000)

Cryptosporidium oocysts are small and very difficult to detect under the microscope with normal testing methods.

Treatment  Cryptosporidium oocysts (the infective stage) are very tough.  They resist bleach and most other normal cleansers.  Only prolonged exposure to ammonia or extreme temperatures can kill them.  The most reliable way to decontaminate drinking water which may be contaminated by Cryptosporidium is to boil it.

Treatment  There is no reliable treatment for cryptosporidium enteritis. Certain agents may be used, but usually have only temporary effects.  Treatment is primarily supportive.  A lactose-free diet should be taken as tolerated. In rare situations, intravenous fluids may be required.  Antibiotics are not usually helpful, and are primarily reserved for people severely affected by the disease and have a weak immune system.  Relapses may happen.

References  Falkenstein, D. (2010) Food Poison Journal. Cryptosporidium part of the Belgium, Wisconsin E. coli cluster. Retrieved May 31, 2010 from  Khan, O. (2007) A Review of Cryptosporidiosis. Cryptosporidium parvum. Retrieved May from  Harris, R., Adrian, M., Petry, F. (2003) Structure of the Cryptosporidium Parvum. A metabolically and osmotically labile apicomplexan organelle. Retrieved May 30, 2010 from  Wikipedia. Cryptosporidium. Retrieved May 31, 2010 from