[Source: US Centers for Disease Control and Prevention (CDC), Emerging Infectious Diseases Journal, full page: (LINK). Abstract, edited.]
Volume 25, Number 11—November 2019 / Dispatch
Human-to-Human Transmission of Influenza A(H3N2) Virus with Reduced Susceptibility to Baloxavir, Japan, February 2019
Emi Takashita , Masataka Ichikawa, Hiroko Morita, Rie Ogawa, Seiichiro Fujisaki, Masayuki Shirakura, Hideka Miura, Kazuya Nakamura, Noriko Kishida, Tomoko Kuwahara, Hiromi Sugawara, Aya Sato, Miki Akimoto, Keiko Mitamura, Takashi Abe, Masahiko Yamazaki, Shinji Watanabe, Hideki Hasegawa, and Takato Odagiri
Author affiliations: National Institute of Infectious Diseases, Tokyo, Japan (E. Takashita, H. Morita, R. Ogawa, S. Fujisaki, M. Shirakura, H. Miura, K. Nakamura, N. Kishida, T. Kuwahara, H. Sugawara, A. Sato, M. Akimoto, S. Watanabe, H. Hasegawa, T. Odagiri); Ichikawa Children’s Clinic, Kanagawa, Japan (M. Ichikawa); Eiju General Hospital, Tokyo (K. Mitamura); Abe Children’s Clinic, Kanagawa (T. Abe); Zama Children’s Clinic, Kanagawa (M. Yamazaki)
In 2019, influenza A(H3N2) viruses carrying an I38T substitution in the polymerase acidic gene, which confers reduced susceptibility to baloxavir, were detected in Japan in an infant without baloxavir exposure and a baloxavir-treated sibling. These viruses’ whole-genome sequences were identical, indicating human-to-human transmission. Influenza virus isolates should be monitored for baloxavir susceptibility.
Keywords: Influenza A; H3N2; Seasonal Influenza; Antivirals; Drugs resistance; Baloxavir; Japan.