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Amebiasis is an infection caused by a one-celled parasite called Entamoeba histolytica (E. histolytica). Amebiasis is uncommon in California, with about 300 cases reported per year. A person can get amebiasis when they:

  • Swallow food or water contaminated with E. histolytica
  • Put anything into their mouth that is contaminated with the feces of a person infected with E. histolytica
  • Touch surfaces contaminated with E. histolytica and then put their fingers in their mouth

Amebiasis is more common among people living in developing tropical countries with untreated water, poor sanitation, and limited access to toilets. These countries include India, parts of Central and South America, and parts of Africa. People living in the United States do not often get amebiasis. Those at greater risk include: 

  • People who have traveled to or immigrated from developing tropical countries
  • People living in housing without access to clean water and proper toilets/sanitation
  • Men who have sex with men  

The symptoms of amebiasis can begin two to four weeks after being infected. Only 10%–20% of those infected ever develop symptoms. Symptoms are often mild and may include:

  • fatigue or tiredness
  • watery or bloody diarrhea
  • excessive intestinal gas
  • stomach cramps 
  • weight loss
  • fever

Rarely, E. histolytica can invade the liver and cause an abscess (a collection of pus), or spread outside of the intestines to other organs. Those with a weakened immune system may become seriously ill and have more severe symptoms.

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