A Comparison of the Infection Rate and Gross Pathology of Amebic Infection in Normal and Antigen-Injected Rats

Abstract

Summary This study was designed to assess by selected criteria the capacity of amebic antigen to influence the resistance to infection and the gross pathology in young rats on subsequent exposure to Endamoeba histolytica. Whereas 37 per cent of 90 antigen-injected rats did not develop amebic lesions, only 8 per cent of 83 control animals, which received no antigen prior to inoculation failed to develop lesions. The infection rate and average degree of infection in antigen-injected animals were 63 per cent and 2.6 respectively. In contrast, the control rats had an infection rate of 92 per cent and an average degree of infection of 4.6. The data obtained appear to indicate a definite influence of the amebic antigen on the infection rate and on the average degree of infection in rats.