Amebic liver abscess. Report of a case presenting with nonreactive serologic tests for Entamoeba histolytica.

We present a patient with an acute amebic liver abscess with nonreactive serologic tests. Motile hematophagous trophozoites of Entamoeba histolytica were seen microscopically in scrapings from the wall of the abscess. Postoperative serologies revealed rapidly rising then falling titers by SAFA and IHA antibody assays. Serologic tests for amebiasis may be reative in greater than 95% of patients with invasive amebiasis. Nevertheless, a reactive serologic test should not be relied upon exclusively to establish the diagnosis. Sequential serologic testing and surgical intervention to obtain material for microscopic examination, gram stain and bacteriologic culture are warranted in patients with hepatic abscess and nonreactive serologic tests for antibodies to E. histolytica.