[Localization of a variant of herpes simplex virus type 1 in the western Japan]

We previously reported that a variant of herpes simplex virus type 1, which we found by Bg1 II digestion of many Japanese HSV-1 isolates' DNA's, was isolated frequently in two regions of Western Japan, i.e. Yamaguchi and Fukuoka. In this paper, we analyzed 280 more isolates from eleven regions in Japan. In four western regions of Japan, i.e. Osaka, Shimane, Yamaguchi, and Fukuoka, the isolation frequency of the variant was very high, and its proportion among all the isolates from those regions was 30 to 50%. On the other hand, in four eastern regions of Japan, i.e. Akita, Iwate, Miyagi, and Yamanashi, the proportion was 0 to 11%. In two central regions, i.e. Aichi and Kyoto, the proportions were 16 and 22%, respectively. Thus, the variant seems to be localized in the western regions of Japan.