1991 Volume 103 Issue 5-6 Pages 637-643
Hemagglutination inhibition (HI) reaction of Japanese encephalitis was determined with the sera of inpatients at a hospital in Kurashiki City.
The ratio of inpatients having a hemagglutination inhibition (HI) reaction abobe 10 to all patients decreased from 86.8% in 1982 to 67.9% in 1985, indicating that about one third of the patients had trace HI antibody in 1985.
The titer of HI antibody in inpatients decreased yearly. The titer obtained in 1984 was significantly lower than that obtained in 1983 and the titer obtained in 1985 was significantly lower than that obtained in 1984. Thus the biological half life of HI titer in the sera of inpatients was 1.8 years.
