Serological studies of the self-cure reaction in sheep infected with Haemonchus contortus

Abstract

The serological reactions which take place during self-cure of sheep infected with Haemonchus contortus were investigated by complement fixation, haemagglutination, and the Ouchterlony agar diffusion precipitin techniques. In addition, a test to detect incomplete antibodies was applied to certain sera. Absorption tests demonstrated that the antibodies detected by the complement fixation test and the haemagglutination test could be differentiated. Evidence is presented to show that the main antigenic stimulation at self-cure is derived from substances released by larvae during the third ecdysis.