Giardiasis and Cryptosporidiosis

Giardiasis and Cryptosporidiosis

This information was summarized from the following URL of Health Canada

(September 14, 2001): http://www.hc-sc.gc.ca/ehp/ehd/catalogue/general/iyh/giardia.htm

General Information

Giardia and Cryptosporidium are microscopic, protozoan parasites that can be found in water contaminated with the feces of infected animals.
Giardia are often found in human, beaver, muskrat, and dog feces. In humans, Giardia causes an intestinal illness called giardiasis or "beaver fever". Cryptosporidium is responsible for a similar illness called cryptosporidiosis.
Giardia and Cryptosporidium parasites produce cysts that are very resistant to harsh environmental conditions. When ingested, they germinate, reproduce, and cause illness. After feeding, the parasites form new cysts, which are then passed in the feces. Studies have shown that ingestion of only a few cysts will cause illness in humans.

Symptoms, Treatment and Risk Reduction

Gastrointestinal upset, malaise, and weight loss are the most common symptoms caused by Giardia. Vomiting, chills, headache, and fever may also occur. These symptoms usually surface 6 to 16 days after the initial contact and can continue as long as a month. The symptoms of cryptosporidiosis are similar; the most common include watery diarrhea, abdominal cramps, nausea, and headaches. These symptoms occur within 2 to 25 days of infection and usually last one or two weeks; in some cases they may persist for up to a month.
Anti-parasitic drugs are available and are particularly helpful for people with impaired immune systems in whom the illness could otherwise develop into a persistent state. Anti-diarrheal drugs and re-hydration therapy may be used if diarrhea becomes severe. No drugs to fight the illness have been approved, though many are now being tested. If you are suffering from diarrhea and suspect that your symptoms may be due to Giardia or Cryptosporidium, visit your physician and mention any exposure you may have had to water, food, or feces that may have been contaminated by the parasites.
In the outdoors, water should be boiled for at least one minute before it is used for drinking, food preparation or dental hygiene . This treatment will destroy not only Giardia and Cryptosporidium, but also any other disease-causing microorganisms that might be present. Certain types of filters can also remove the parasites. Travelers to countries where the safety of drinking water is suspect should boil or disinfect and filter water that is to be used for drinking, food preparation, or dental hygiene.