抄録
The hemagglutination inhibition test has been performed against the Japanese B encephalitis virus on sera collected not only from the patient (31 cases, 37 test samples) but also from the normal habitants (28 cases) in both Tokyo and northern part of Hokkaido and from the poliomyelitis cases (10 cases) in order to estimate its diagnostic value. The virus which was used as the antigen had been isolated from the case in the summer 1951 and was transferred brain to brain within the 10th generation.
The test was found to be specific for the Japanese B encephalities if more than 1:160 in the inhibition tier was read as positive, because the serum from the normal persons and the poliomyelitis cases showed the titer essthan 1:80. There is a certain correlation between the daily occurrence of the inhibition titer and that of the complement fixing antibody. The titer of the inhibition test became, however, positive at the end of the first week after the onset of disease, reached the maximum in the 3 weeks and began to lower in the 2 months. At any rate it becomes positive at the earlier stage of disease when the complement-fixation test proves still negative. In other words it seems very likely that the hemagglutination inhibition test is more sensitive than the complementfixation test.
