Center for Disease Control, Public health Service, U.S. Department of Health, Education, and Welfare, Department of Human Microbiology, the Sackler School of Medicine, Tel Aviv University, Atlanta, Georgia 30333, Israel
Results of testing 298 sera from hamsters inoculated in the liver with Entamoeba histolytica and from 25 uninoculated controls by indirect hemagglutination (IHA) and enzyme linked immunosorbent assay (ELISA) showed that measurable amounts of antibody appeared as early as 5 days after inoculation, generally increased to a high level within 20 days, and persisted for the duration of the experiments (58 days). There was fair correlation between size of liver lesion and titers. Strain differences in amebae used for antigen and for inoculation could not be detected by either test. The IHA test appeared to be very sensitive, and titers of 1:16 and above were specific. With the ELISA technique, it was tentatively concluded that titers of 1:32 were specific for anti-amebic antibodies but only those of 1:128 and above were indicative of liver infections in the experimentally infected hamsters.