Co-agglutination test for the detection of circulating antigen in amebic liver abscess

We report here a simple and economical slide agglutination test, the co-agg lutination (Co-A) test, for the detection of circulating amebic antigen in sera for the diagnosis of amebic liver abscess. Fifty serum specimens from cases of amebic liver abscess. 25 from other individuals with parasitic and miscellaneous infections, and 25 from healthy controls were tested for the presence of serum antigen by the Go-A test. Forty-five (90%) amebic liver abscess sera were found to be amebic-antigen positive by the Go-A test. Non e of 25 sera from healthy controls were positive for the antigen. However, false-positive results were seen with two sera from those with other parasi tic and miscellaneous infection controls. These results show that the Go-A test can be used as a sensitive and specific rapid slide agglutination test for the detection of amebic antigen in the sera for diagnosis of cases of amebic liver abscess in a routine parasitology laboratory.