Influenza A(H1N1)pdm09 virus exhibiting reduced susceptibility to baloxavir due to a PA E23K substitution detected from a child without baloxavir treatment
Emi Takashita, Takashi Abe, Hiroko Morita, Shiho Nagata, Seiichiro Fujisaki, Hideka Miura, Masayuki Shirakura, Noriko Kishida, Kazuya Nakamura, Tomoko Kuwahara, Keiko Mitamura, Masataka Ichikawa, Masahiko Yamazaki, Shinji Watanabe, Hideki Hasegawa, Rika Komagome, Asami Ohnishi, Rika Tsutsui, Masaki Takahashi, Mie Sasaki, Shiho Tamura, Chihiro Shibata, Kenichi Komabayashi, Nozomi Saito, Aoi Saito, Fuminori Mizukoshi, Akira Wakatsuki, Hiroyuki Tsukagoshi, Noriko Suzuki, Y Uno, Noriko Oitate, Wakako Nishikawa, Mami Nagashima, Sumi Watanabe, Chiharu Kawakami, Hideaki Shimizu, H Amano, Satoko Kanazawa, K. Watanabe, Kazunari Yamamoto, Tetsuya Yoneda, Sachiko Nakamura, Kaori Sato, Masayuki Oonuma, Michiko Takeuchi, Erina Tanaka, Masahiro Nishioka, Yusuke Sato, Yukiko Sakai, Takaharu Maehata, Toshihiko Furuta, Yoshihiro Yasui, Takuya Yano, Asa Tanino, Sachi Hirata, Akiko Nagasao, Satoshi Hiroi, Hideyuki Kubo, Fumika Okayama, Tomohiro Oshibe, Ai Mori, Ryutaro Murayama, Shoko Chiba, Yuki Matsui, Yuko Kiguchi, Koji Takeuchi, Tetsuo Mita, Nomiya Kayoko, Yukie Shimazu, Yoshiki Fujii, Shoichi Toda, Yumiko Kawakami, Yukari Terajima, Mayumi Yamashita, Tomiyo Takahashi, Yuki Ashizuka, Chinami Wasano, Takashi Kimura, Sanae Moroishi, Miho Urakawa, Takashi Sakai, Kaori Nishizawa, Toru Hayashi, Yu Matsuura, Y. Hamada, Yumani Kuba
Abstract
Human-to-human transmission of PA I38 mutant influenza A(H3N2) viruses with reduced baloxavir susceptibility has been reported in Japan. In December 2019, we detected a PA E23K mutant A(H1N1)pdm09 virus from a child without baloxavir treatment. The PA E23K mutant virus exhibited reduced baloxavir susceptibility but remained susceptible to neuraminidase inhibitors. Epidemiological data suggest possible transmission of this PA E23K mutant virus among humans, although its growth capability relative to that of the wild-type virus was reduced. Therefore, baloxavir susceptibility monitoring of influenza viruses is essential.