Jpn. J. Infect. Dis., 65 (2), 187-191, 2012

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Hiroshi Yoshikura*

National Institute of Infectious Diseases, Tokyo 162-8640, Japan

Communicated by Haruo Watanabe

(Accepted January 31, 2012)

*Corresponding author: Mailing address: Department of Food Safety, Ministry of Health, Labour and Welfare, 1-2-2 Kasumigaseki, Chiyoda-ku, Toyo 100-8916, Japan. E-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.