Seroepidemiological Studies on the Japanese Encephalitis Influence of the “Retrospective Reaction” on C.F. Antibody of Latently Infected Persons
1960 Volume 33 Issue 11 Pages 987-1003
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1960 Volume 33 Issue 11 Pages 987-1003
Eight hundred fifty seven persons were investigated by the author et al on the C.F. reaction 3.207 times in total and 103 persons on the neutralization test at 8 different periods from November 1951 to February 1954 in Tsukurimichi of Shinminato City of Toyama Prefecture. In this campaign, personal accumulation of C.F. antibody was recognized by our co-worker Tsuchiya with the latently infected persons. On the other hand, it was found by Kitaoka that men and horses who are thought to have experienced in the past a latent infection of japanese encephalitis demonstrate a tendency of easy rise of antibody titer in the inoculation experiments of vaccin, which phenomenon was called by him as “retrospective reaction”. From these results of two workers it is assumed that the personal accumulation of C.F. antibody in latently infected persons is due to “retrospective reaction”. In this paper, the shift of C.F. antibody due to “retrospective reaction” was investigated. The results were as follows:
1) The persons who had the history of positive C.F. reaction demonstrated thereapparition of C.F. antibody due to “retrospective reaction”.
2) The cases with repeated or frequent positive C.F. reactions demonstrated a longer duration of antibody because of the more marked “retrospective reaction”. Consequently, the rate of negative reaction was particularly low among these cases.
3) The cases which had a history of positive C.F. test demonstrated an obviously high positive rate. The personal accumulation of C.F. antibody results principally from the “retrospective reaction”.
4) The cause of this “retrospective reaction” was sought in the infection by japanese encephalitis virus.
5) According to the animal experiments carried out in order to study the shift of C.F. antibody due to reinfection of this virus, C.F. antibody titer of guinea pigs increased readily in the early stage, when Nakayama strain of Japanese encephalitis virus was reinoculated to them, after the titer had decreased following the first inoculation of this virus.
