Amebiasis and Amebic Liver Abscess in Children.

Although rare in the developed world, amebiasis continues to be a leading cause of diarrhea and illness in developing nations with crowding, poor sanitation, and lack of clean water supply. Recent immigrants or travelers returning from endemic regions after a prolonged stay are at high risk of developing amebiasis. A high index of suspicion for amebiasis should be maintained for other high-risk groups like men having sex with men, people with AIDS/HIV, immunocompromised hosts, residents of mental health facility or group homes. Clinical presentation of intestinal amebiasis varies from diarrhea to colitis and dysentery. Amebic liver abscess (ALA) is the most common form of extraintestinal amebiasis. Various diagnostic tools are available and when amebiasis is suspected, a combination of stool tests and serology should be sent to maximize the yield of testing. Treatment with an amebicidal drug such as metronidazole/tinidazole and a luminal cysticidal agent such as paromomycin for clinical disease is indicated. However, for asymptomatic disease treatment with a luminal cysticidal agent to decrease chances of invasive disease and transmission is recommended.

Amebic liver abscess.

We report eight cases of amebic liver abscess. All patients were men, and four were homosexual. Five of the eight patients had syphilis, but the four homosexual patients who were tested for HIV infection were negative. Ultrasonography (US), with or without needle aspiration, is the best method for diagnosing amebic liver abscess, and the treatment of choice is US-guided needle aspiration of the abscess followed by metronidazole therapy. Complication by other sexually transmitted diseases is another important factor affecting the treatment of this disease.

Amebic liver abscess in a homosexual man.

A case report of a 36-year-old black homosexual man with right upper- and lower-quadrant abdominal pain is presented. When exploratory surgery for appendicitis was performed, an abscess, consistent with an amebic abscess, was encountered in the right lobe of the liver. This abscess was evacuated, and a drain was placed. A serum sample taken at the time of surgery showed high titers of antibody to Entamoeba histolytica; metronidazole therapy was instituted, and the patient made an uneventful recovery. Since amebiasis is epidemic in the gay community, health care personnel should be aware of the various modes of transmission, as well as of the diagnoses, optimal management, and indications for surgery in patients with amebic liver abscess. It is noted that amebic liver abscess appears to be a less frequent complication of amebiasis among the male homosexual population than among other groups.

Endemic amebiasis in an extended family.

Two cousins from a large Spanish-American family were simultaneously diagnosed as having amebic liver abscesses. Survey of 183 extended-family members revealed that 45.7% of 162 had a positive amebiasis indirect hemagglutination test and 12.6% of 111 had cysts or trophozoites of Entamoeba histolytica demonstrated in a single stool examination. A total of five family members had had liver abscesses; two deaths had occurred. In a random sample survey of the remainder of the community, only one person (0.3%) had a positive serologic test. Within the extended family, person-to-person appeared to be the predominant mode of transmission. Water supplies were not contaminated. Both community and extended family homes had the same source of water. Type and source of food supply were not correlated with infection and there was no evidence to implicate an infected food handler. Clustering of seropositivity occurred in homes without indoor toilets. Homes of the extended family were more crowded and significantly fewer of them had indoor toilets. Endemic foci of amebiasis continue to exist in the United States. Follow-up family and other close contacts of persons with amebiasis will frequently identify other cases.