Epidemiological and Ecological Studies of Japanese Encephalitis in Okinawa, Subtropical Area in Japan. I. Investigations on Antibody Levels to Japanese Encephalitis Virus in Swine Sera and Vector Mosquito in Okinawa, Miyako and Ishigaki Islands

J-STAGE
  • Tadano Masayuki
    Department of Virology, Faculty of Medicine, University of the Ryukyus
  • Kanemura Kazumi
    Department of Virology, Faculty of Medicine, University of the Ryukyus
  • Hasegawa Hideo
    Department of Parasitology, Faculty of Medicine, University of the Ryukyus
  • Makino Yoshihiro
    Department of Virology, Faculty of Medicine, University of the Ryukyus
  • Fukunaga Toshihiko
    Department of Virology, Faculty of Medicine, University of the Ryukyus

抄録

From 1985 to 1989, serum specimens of swine raised in the northern, central and southern areas in Okinawa island were examined for Japanese encephalitis (JE) virus antibody by ELISA and hemagglutination-inhibition test. The antibody positive rate was found to be higher in the north and central than in the south. The 2-mercaptoethanol sensitive antibody to JE was detected mostly in June and July, and occasionally in other months except February and March. There was no month when all specimens from three areas turned antibody-negative simultaneously, indicating that JE virus transmission to swine lasted longer in Okinawa island than in other temperate areas in Japan. From 1986 to 1991, the vector mosquitoes (Culex tritaeniorhynchus) were collected in a pig farm in the south of Okinawa island. A total of 153 strains of JE virus was isolated from the vector mosquitoes mainly in June. In Miyako and Ishigaki islands, the antibody positive rate in swine sera was found to be extremely low, compared with that in Okinawa island. In Miyako island, where no paddy rice field is cultivated, a few adults as well as larvae of the vector mosquito were collected, while in Ishigaki island, where there are many watered rice fields, a lot of adults as well as larvae were collected. Although the environmental situation is quite different between the two islands, JE virus transmission appeared to be very low in both islands.

収録刊行物

詳細情報 詳細情報について

問題の指摘

ページトップへ