Haemoagglutinin inhibition test (HI test) of Japanese B Encephalitis was conducted in the people, pigs and heron that lived in Okayama Prefecture in 1966, and following results were obtained.
1. The first epidemic in the pigs in the year was shown on the middle of June and 20% of the pigs showed positive HI test, 1:160 or above. The second wide epidemic in the pigs was also observed in the begining of August and all of the pigs showed positive HI test. The above results were obtained from the HI test of pigs in the slaughterhouses, and the HI test of serum obtained from the ear veine of pigs in the breeding house also showed similar results.
2. On the HI test of night heron, caught at the nests in the mountain at Tsudaka Village, half of heron showed positive reaction. However HI test of white heron lived in the nests near the nests of night heron, showed negative reaction.
3. On the HI test of inhabitants in Higashiawakura Village, where the patient of Japanese B Encephalitis has not been found, a half of the inhabitants injected Japanese B Encephalitis vaccine showed positive reaction and the non vaccinated group showed negative reaction.
4. The high specific active antibody of HI reaction was prepared from pig γ globulin by DEAE cellulose column çhromatography.