Amebic liver abscess
Amebic liver abscess is a collection of pus in the liver in response to an intestinal parasite called Entamoeba histolytica.
Hepatic amebiasis; Extraintestinal amebiasis; Abscess - amebic liver
Amebic liver abscess is caused by Entamoeba histolytica. This parasite causes amebiasis, an intestinal infection that is also called amebic dysentery. After an infection has occurred, the parasite may be carried by the blood from the intestines to the liver.
The disease spreads from eating food or water that has been contaminated with feces (sometimes due to the use of human waste as fertilizer). It is also spread 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 from this disease.
Risk factors for amebic liver abscess include:
- Immunosuppression, including HIV infection
- Old age
- Recent travel to a tropical region
- Steroid use
There are usually no symptoms of intestinal infection. But people with amebic liver abscess do have symptoms, including:
- Abdominal pain, particularly in the right, upper part of the abdomen; pain is intense, continuous or stabbing
- Fever and chills
- Diarrhea (in only one-third of patients)
- General discomfort, uneasiness, or ill feeling (malaise)
- Hiccups that do not stop (rare)
- Loss of appetite
- Weight loss
Exams and Tests
Tests that may be done include:
- Abdominal ultrasound
- Abdominal CT scan or MRI
- Complete blood count
- Liver abscess aspiration to check for bacterial infection in the liver abscess
- Liver scan
- Liver function tests
- Blood test for amebiasis
- Stool testing for amebiasis
Antibiotics such as metronidazole (Flagyl) or tinidazole (Tindamax) are the usual treatment for liver abscess. A drug such as paromomycin or diloxanide must also be taken to get rid of all the ameba in the intestine and to prevent the disease from coming back. This treatment can usually wait until after the abscess has been treated.
In rare cases, the abscess may need to be drained using a catheter or surgery to relieve some of the abdominal pain.
Without treatment, the abscess may break open (rupture) and spread into other organs, leading to death. People who are treated have a very high chance of a complete cure or 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.
When to Contact a Medical Professional
Call your health care provider if you develop symptoms of this disease, especially if you have recently traveled to an area where the disease is known to occur.
When traveling in tropical countries with poor sanitation, drink purified water and do not eat uncooked vegetables or unpeeled fruit.
Petri WA, Haque R. Entamoeba species, including amebic colitis and liver abscess. In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. 8th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 275.
Wolf PS, Park JO. Liver abscess: pyogenic and amebic hepatic abscess. In: Jong EC, ed. Netter's Infectious Diseases. Philadelphia, PA: Elsevier Saunders; 2012:chap 47.
Reviewed By: Jatin M. Vyas, MD, PhD, Assistant Professor in Medicine, Harvard Medical School; Assistant in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital, Boston, MA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.