Volume 38, Issue 2
  • ISSN: 0002-9637
  • E-ISSN: 1476-1645



Outbreaks of abortion and stillbirth caused by Japanese encephalitis virus were observed in swine populations in Hokkaido in 1984 and 1985. Two strains of Japanese encephalitis virus were isolated from aborted fetuses in different outbreaks, and the antigenic types of the strains found to be different from Nakayama and JaGAr-01. The outbreak of 1985 was in early June, the interepidemic period of Japanese encephalitis in northern temperate zones. A seroepidemiological survey carried out from 1984 to 1986 in 14 districts showed high rates of Japanese encephalitis antibody in swine sera in two districts. A more detailed 3-year survey showed that pig farms positive for Japanese encephalitis antibody were detected at the same sites in Hiroshima near Sapporo as negative farms. These data suggest that Japanese encephalitis virus is maintained in a distinct endemic focus and has the capacity to overwinter locally in Hokkaido.


Article metrics loading...

The graphs shown below represent data from March 2017
Loading full text...

Full text loading...

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error