1959 Volume 9 Issue 2 Pages 191-198
1) During the course of the studies on the acute respiratory infection among children which were found in Tokyo area during the period between January, 1956 and February, 1958, isolation of causative virus from part of the sick children was attempted. Attempts were made on the throat washings and throat mucus collected from 5 cases who were diagnosed HVJ infection serologically. Two strains of HVJ were thus isolated.
Hazeyama strain was isolated by direct intraamniotic inoculation of the throat washing collected on the 1st day of disease from an 11 year-old boy who was suffering from acute laryngitis and exacerbation of acute nephritis, The identification of this strain to HVJ was made at the Fukumi Laboratory of the National Institute of Health.
Sakai strain was isolated by direct intraamniotic inoculation of throat mucus collected on the 5th day of disease from a 4 year 11 months old girl who was suffering from acute bronchitis. This strain was identified to HVJ by cross hemagglutination inhibition tests with antisera against influenza A and B viruses, mumps virus and HVJ. The reconvalescent serum of this case was negative in the HVJ complement fixation test even at the dilution of 1:4, but it was HVJ hemagglutination inhibition test positive up to the dilution as high as 1:1024.
2) Neutralization tests by fertilized hens'eggs were conducted by serum dilution method on 5 paired specimens randomiy selected from the specimens from cases of HVJ infection. In all cases, the convalescent serum showed distinct rise in the neutralizing antibody titer.
Within the 3rd week of the disease, neutralizing antibody titer, complement fixation titer and hemagglutination inhibition titer were found rising in parallel with each other, though complement fixation titer showed a tendency of falling thereafter. In the Case No. 3, the serum collected on the 144th day of disease showed negative results in the complement fixation test and hemagglutination inhibition test, but the neutralizing antibody titer was found still remarkably high. The above suggests that the neutralizing antibody titer and hemagglutination inhibition titer fluctuate not necessarily in parallel each other.
