DISTRIBUTION OF ANTIBODIES TO INFLUENZA-A VIRUS IN CHICKENS IN JAPAN

A serological surveillance was carried out to detect antibody against influenza A virus in chicken sera. A total of 8,850 field samples were collected from 47 prefectures in Japan. Initially, all the sera were screened by agar gel immunodiffusion and those sera showing positive r eaction were investigated for haemagglutination-inhibition (HI) and ne uraminidase-inhibition antibodies against influenza viruses. Only 6 sa mples had antibodies; 4 sera had antibodies against human subtype H1N1 virus; with HI activity against strain A/PR/34; three sera had strong HI activity to strain A/Tottori/4/87, which by haemagglutination test is closely related to A/Yamagata/120/86. The remaining two chicken se ra had antibodies against avian subtypes H10N4 and H3N6 viruses respec tively.