Amebic liver abscess is a collection of pus in the liver brought on by an intestinal parasite.

Amebic liver abscess is caused by Entamoeba histolytica, the same organism that causes amebiasis, an intestinal infection also called amebic dysentery. The organism is carried by the blood from the intestines to the liver.

The disease spreads through ingestion of amebic cysts in food or water contaminated with feces (sometimes due to use of human waste as fertilizer), and through person-to-person contact.

The infection occurs worldwide, but is most common in tropical areas where crowded living conditions and poor sanitation exist. Africa, Latin America, Southeast Asia, and India have significant health problems associated with this disease.

Risk factors for amebic liver abscess include:

• Alcoholism
• Cancer
• Homosexual activity, particularly in men
• Immunosuppression
• Malnutrition
• Old age
• Pregnancy
• Recent travel to a tropical region
• Steroid use

There may or may not be symptoms of intestinal infection. Symptoms may include:

• Abdominal pain
  • Particularly in the right, upper part of the abdomen
  • Intense, continuous, or stabbing pain
• Chills
• Diarrhea
• Fever
• General discomfort, uneasiness, or ill feeling (malaise)
• Jaundice
• Joint pain
• Loss of appetite
• Sweating
• Weight loss

Tests that may be done include:

• Abdominal ultrasound
• Abdominal CT scan or MRI
• Complete blood count
• Liver biopsy - rarely done due to high risk of complications
• Liver scan
• Liver function tests
• Serology for amebiasis
• Stool testing for amebiasis

An antibiotic medicine called metronidazole (Flagyl) is the usual treatment for liver abscess. A medication such as iodoquinol must also be taken to get rid of all the amebas in the intestine, to prevent the disease from coming back. This can usually be delayed until after the abscess has been treated.

In rare cases, the abscess may need to be drained to help relieve some of the abdominal pain.

Without treatment, the abscess may rupture and spread into other organs, leading to death. Persons who receive treatment have a very high chance of a complete cure or having only minor complications.

The abscess may rupture into the abdominal cavity, the lining of the lungs, the lungs, or the sac around the heart. The infection can also spread to the brain.

Call your health care provider if you develop symptoms of this disease, especially if you've recently traveled to an area where the disease is known to occur.

When traveling in tropical countries where poor sanitation exists, drink purified water and do not eat uncooked vegetables or unpeeled fruit.

Neuschwander-Tetri BA. Bacterial, parasitic, fungal, and granulomatous liver disease. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier. 2007: chap 155.