Amebiasis

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What is amebiasis?

Amebiasis is an intestinal illness caused by the parasite entamoeba histolytica. Amebiasis occurs worldwide and approximately 10% of the world’s population is infected with this parasite. It is usually a disease of young adults and is rarely found in children under 5. The illness is usually more prevalent in areas of poor sanitation.

Most people who are infected do not have any symptoms. The symptoms include chills, fever, cramps, bloody diarrhea, or constipation. It usually takes 2-4 weeks from the time of swallowing the parasite to when the symptoms start. It is recommended that treatment be taken to kill the parasite. The illness lasts about three weeks with medication but can last longer if untreated. People working in patient care and food handling should not return to work until treatment is initiated.

How do amebiasis infections happen?

Infections happen after eating food or drinking water that has been contaminated by faeces that contain the amebic cysts. The parasite is transmitted from person to person by the fecal-oral route. The parasite is excreted in stool and makes its way to another person through contaminated hands or objects. Water can be contaminated with human wastes. Raw vegetable contamination can occur if human waste is used as fertilizer and although this is not permitted in Canada, it is a practice still followed in some parts of the world putting travelers at risk. Sexual transmission can also occur by anal-oral contact.

How is amebiasis prevented?

• Thorough hand washing is the best prevention. Make sure hands are properly washed after using the toilet, handling diapers and preparing food.
• Do not eat raw shellfish.
• Drink water from a safe supply. When traveling, boil water for at least one minute if you are unsure of the supply or use bottled water. Ice cubes made from contaminated water may also carry the parasite.
• Wash or peel all fruits and vegetables before eating.
• If you are ill with diarrhea, avoid preparing or handling food.

For more information call Public Health at 519-376-9420 or 1-800-263-3456.

Canadian Institute of Public Health Inspectors (CIPHI)