A total of l4S2sera of sows, more than 12-month-old of age: were collected from 70 farms over 4 geographical regions in Taiwan HemagglutinatingInhibition (HI) test for detection of antibody were carned out on microtitre system by using hemagglutinating encephalomyelitis virus (1EV) as antigen at dose of 4 hemagalutination (HA) units. Result of the tests revealed that sera from 65 out of 70 farms were shown positive reaction against 1EV antigen, the average positive rate was 2S.65%(41611452).
The distribution of the positive reaction revealed that the southern region was the highest (40.75%); and that in easten region was the lowest (14.17%); nothern and middle regions were 27 and 22.4% respectively.
Antibodies against 1EV were proved form sera collected in Taiwan in l99 and every subseqent year. Sera from 1979, 4532% (155342) of sera collected over 6 counties in southern region of Taiwan were antibody kpositive. therefore, it is concluded that 11EV infection may be widespread in Taiwan at least since 1979.