Amebic liver abscess: Epidemiology, clinical features, and outcome

Amebic liver abscess (ALA) is a serious, but readily treatable form of hepa tic infection. In order to understand the clinical features of this conditi on in the United States, we reviewed the medical histories of 56 patients w ith ALA at two large San Francisco Hospitals from 1979 to 1994. Patients we re divided into the following groups based on the presumed manner in which they had acquired AEA: those born or raised in the United States, with a hi story of travel to an endemic area (Tr-ALA); those from an endemic area, br at living in the United States for less than one year (En-ALA); and those n either from nor having traveled to an endemic area (N-ALA). We found distin ct clinical patterns in patients from different epidemiological groups. Pat ients with Tr-ALA were a decade older than those from endemic regions, were more likely to be male, and tended to have an insidious onset. Furthermore , compared to patients with En-ALA, those with Tr-ALA were more likely to h ave hepatomegaly (P < 0.0001) and large abscesses (ALA >10 cm; P < 0.01). O ne third of the patients studied had no associated travel history Or endemi c origin as risk factors. Of these, 63% had a condition consistent with sev ere immunosuppression, such as infection with the human immunodeficiency vi rus (HIV), malnourishment with severe hypoalbuminemia, or chronic infection . In patients with N-ALA, the presence of a presumed immunosuppressed state increased significantly, as compared to patients with endemic or travel ri sk factors for ALA. During the last five years of the study, one third of a ll patients diagnosed with ALA were HIV positive (including 2 with a new di agnosis of AIDS), many of whom were discovered to be HIV-infected only afte r presentation with ALA, We conclude that travel to and origin In an endemi c area are important risk factors for the development of ALA, and patients in these different epidemiological groups appear to have distinct clinical features. Further, in the absence of recognized risk factors, the developme nt of ALA may suggest an immunocompromised host.