An infection in the intestines caused by a parasite.   It is commonly transmitted by drinking fecally contaminated water(freshwater or unfiltered surface water).  Infected people can have a range of symptoms from completely asymptomatic to chronic diarrhea with abdominal cramps.  Filtering water with a “cyst removal” filter or boiling water for at least one minute are the most effective ways to treat your water.  Iodine and chlorine are less effective.


Symptoms generally appear within one to three weeks after becoming infected and can include:

• Diarrhea

• Gas

• Nausea and/or stomach cramps



If you think you may have giardia, contact your healthcare provider for testing and treatment.



The CDC recommends the following prevention techniques:

• Avoid water (drinking and recreational) that may be contaminated.

• Do not swallow water while swimming in pools, hot tubs, fountains, lakes, rivers, springs, ponds, streams, or the ocean.

• Do not drink untreated water from lakes, rivers, springs, ponds, streams, or shallow wells.

• Do not drink untreated water or use ice when traveling in countries where the water supply might be unsafe.

If the safety of drinking water is in doubt, do one of the following:

• Drink bottled water.

• Disinfect tap water by heating it to a rolling boil and letting it boil for 1 minute.

• Use a filter that has been tested and rated by National Safety Foundation (NSF) Standard 53 or NSF Standard 58 for cyst and oocyst reduction; filtered tap water will need additional treatment to kill or weaken bacteria and viruses.