Periodic observations were made on 450 healthy kitchen workers of two heavy industry companies (330), two food-stuff dealers companies (80), a medical institute (20) and a school (20) in Kobe city for the study of carrier rate and duration of carrier state of Vibrio parahaemolyticus (VP) during oneyear-period from Jan. to Dec., 1968. The results obtained were evaluated as to whether VP carriers play a significant role as the source of foodpoisoning epidemics.
Isolations of Vibrio alginolyticus (VA), which is said to be non-pathogenic, were paralleled in addition.
The number of persons, who were found to be VP carrier state in the period, is 17 in all, approximately 0.3% of all examined. A period, in which VP was detectable, was only from June to October, that is compatible with the fact that VP is densely distributed in the coastal sea at that period. Monthly rate of VP isolations was 0.2% for June, 0.2 July, 0.6 August, 0.3 September, and 0.2 October.
Isolation rate of VA was almost the same as that of VP. Fifteen persons were found positive during May-October, 5 of which were concomitantly VP carriers.
Out of 17 cases from which VP strains were detected, hemolytic (Kanagawa phenomenonpositive) strains were found in only three. In one case of these three, mild diarrhea was observed shortly after the stool sampling. No clinical symptoms were seen in either VP or VA carriers except anabove-mentioned case.
In 27 cases, positive of VP and/or VA, its carrier state was investigated. In all the cases, the organisms disappeared within 3-7 days after the first isolation. It is a sharp contrast with VP food-poisoning cases observed in this country, in which the organisms were detectable mostly as long as 10 to 16 days after the onset of illness.
It is assumed from these findings that healthy adults cannot be long-term and dangerous carriers of VP as long as conditions such as amount of VP intake or resistance of the hosts are not favorable for them to become clinically manifested. Consequently, possibilities for such “healthy transient excreters” to become the source of epidemics would be quite low compared with those for manifested or convarescent patients, if not totally denied.

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For the early diagnosis of Japanese encephalitis (JE), HI or CF has some inconvenience in its time consuming procedures. In this respect, the authors attempted application of direct and indirect Fluorescent Antibody Technique (FAT) to the diagnosis of JE.
The results are summarized as follows:
1) The authors could prove, using direct FAT, the viral antigen in the brain material of two out of five death cases suspected clinically as JE. The usefulness of this technique for the promt diagnosis of death cases were thus proven.
2) In indirect FAT, (1) diagnostically significant Fluorescent antibody (FA) titer rises (four-fold or greater) were seen in 39 (69.6%) out of 56 JE-suspected paired sera. This ratio is almost the same as that (66.6%) of HI tested. (2) The patients used to show high FA titers two or three weeks after the onset of illness. (3) Mostly, FA titers were 1-3 fold (log 2) lower than HI titers. Fluctuations of the titers were, however, fairly coincidental between FA and HI.

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