Micro-indirect hemagglutination test for detection of antibody against transmissible gastroenteritis virus of pigs.

A micro-indirect hemagglutination (IHA) test was developed for detecting antibody against transmissible gastroenteritis (TGE) virus of pigs. TGE virus propagated in swine kidney cell cultures was highly purified and concentrated by the combination of ammonium sulfate precipitation, treatment with fluorocarbon, and sucrose density gradient centrifugation. Tanned sheep erythrocytes were sensitized with purified virus for use in the IHA test. The results of testing 104 serum samples collected from pigs in the field indicated that the IHA antibody titers were approximately five times higher than those obtained by a serum neutralization test and that there was good correlation between the antibody titers determined by the two tests. High IHA antibody titers developed in pigs experimentally exposed to virulent TGE virus. Sensitized sheep erythrocytes were stable under long-term storage at 4 degrees C (at least for 50 days). The conclusions made are that the IHA test described is more sensitive than the serum neutralization test for the detection of TGE antibody and may be of value for serodiagnosis of TGE.