Amebic Liver Abscesses: A New Epidemiological Trend in a Non-endemic Area?

Background: Amoebic liver abscess (ALA) is the most common extraintestinal complication of colonic amebiasis. In recent decades its incidence in developed European countries has significantly increased because of travel and immigration of individuals from highly endemic areas. We report our 29-year experience in echo-guided percutaneous needle/catheter drainage (EPND/EPCD) of ALA. Patients and Methods: From May 1979 to November 2007, 68 ALA corresponding to 56 patients were diagnosed at our Department. All patients were treated with a metronidazole plus EPND/EPCD approach. Results: The majority of the cases did not need more than two echo- guided punctures. Two patients, both male immigrants (HIV- negative), had unmodified lesions after two EPNDs: catheter drainage was performed. A quick worsening of their clinical conditions and onset of neurological symptoms occurred; in both patients, computed tomography (CT) revealed a brain abscess. Intravenous medical therapy was started, but both died 4 and 3 days, respectively, after the onset of neurological symptoms (overall mortality rate: 3.57%). Conclusion: The unfavorable outcome of two cases is a rare example of failure of percutaneous therapy of ALA. Mortality is a possible event even in a non-endemic area such as Italy. More observational data are needed to confirm the possibility of a new epidemiological trend. Amoebic liver abscess (ALA) is the most common extraintestinal complication of colonic amebiasis (1), both in endemic and non-endemic areas. Rates of infection give a clearer picture of the impact of amebiasis on public health. A number of patients ranging between 40,000 and 100,000 die yearly from amebiasis, making this disease the second leading cause of death from parasitic diseases (2). In 1996, 1.3 million cases of intestinal amebiasis were reported in Mexico, consistent with findings of serological studies indicating that more than 8% of the population have had amebiasis (3, 4). In Hue, Vietnam, a city with a population of about 1 million, one hospital reported 1,500 cases of amebic liver abscess over 5 years (5). In Egypt, results of a survey indicated that 38% of individuals presenting with acute diarrhea at an outpatient clinic had amebic colitis (6). In the USA, most cases arise in immigrants from endemic areas, and people living in states that border Mexico have the most disease. In 1993, 2,970 cases of amebiasis were recorded in the USA, 33% of which were in immigrants from Mexico and central and South America, and 17% were from Asia or the Pacific Islands (7). Travellers to endemic areas are also at risk: 10% of 469 individuals with diarrhea after travelling to a developing country were diagnosed with amebiasis in one study, and 0.3% of 2,700 German travellers returning from the tropics were infected with Entamoeba histolytica (8, 9). It is then clear that in recent decades, its incidence in developed European countries has significantly increased because of travel to and immigration from highly endemic areas.