Serum samples had been collected from the swine and human beings (mainly slaughterhouse employees) from June 1978 to September 1979. By means of examining the titer of the HI antibody against the A/NJ/8/76 strain of influenza virus in these samples, the behavior of the virus was studied and the following results were obtained.
(1) There was a remarkable regional difference in the prevalence of the A/NJ/8/76 strain among the swine.
(2) It was suggested that among the swine there might be a seasonal variation in the occurrence of the epizootic caused bythe virus.
(3) In about 9 per cent of the slaughterhouse employees examined, the primary infection of the virus was strongly indicated.
(4) No HI antibody against this virus was found in the serum sample collected from the students of the junior high school in an area surveyed in September, 1979.
From these results, it appears that the virus further continues to be epidemic among the swine.Then the behavior of the virus should be kept under surveillance by conducting serological examinations on the slaughterhouse employees.
