Hemagglutination with rhabdoviruses related to bovine ephemeral fever virus

Three different bovine ephemeral fever group viruses were tested for hemagglutination (HA). One of them, Tortilla Flat virus (CSIRO 368), agglutinated erythrocytes from geese, pigeons, horses, hamsters, mice and guinea-pigs when the concentrated infectious culture fluid was used as a hemagglutinin. The HA was dependent on the pH of phosphate buffered saline used as the erythrocyte diluent when using borate buffered saline (pH 9.0) with 0.4% bovine serum albumin as the antigen diluent. The optimal pH of the phosphate buffer was from 5.2 to 5.8. The HA, however, was not dependent on salt concentration. The incubation temperature did not affect the HA titer significantly. This HA reaction was inhibited by serotype specific antiserum.