Influenza A(H1N1)pdm09 virus exhibiting reduced susceptibility to baloxavir due to a PA E23K substitution detected from a child without baloxavir treatment

• Published in: Antiviral research Vol. 180; p. 104828
• Main Authors: Takashita, Emi, Abe, Takashi, Morita, Hiroko, Nagata, Shiho, Fujisaki, Seiichiro, Miura, Hideka, Shirakura, Masayuki, Kishida, Noriko, Nakamura, Kazuya, Kuwahara, Tomoko, Mitamura, Keiko, Ichikawa, Masataka, Yamazaki, Masahiko, Watanabe, Shinji, Hasegawa, Hideki, Komagome, Rika, Ohnishi, Asami, Tsutsui, Rika, Takahashi, Masaki, Sasaki, Mie, Tamura, Shiho, Shibata, Chihiro, Komabayashi, Kenichi, Saito, Nozomi, Saito, Aoi, Mizukoshi, Fuminori, Wakatsuki, Akira, Tsukagoshi, Hiroyuki, Suzuki, Noriko, Uno, Yuka, Oitate, Noriko, Nishikawa, Wakako, Nagashima, Mami, Watanabe, Sumi, Kawakami, Chiharu, Shimizu, Hideaki, Amano, Hazime, Kanazawa, Satoko, Watanabe, Kaori, Yamamoto, Kazunari, Yoneda, Tetsuya, Nakamura, Sachiko, Sato, Kaori, Oonuma, Masayuki, Takeuchi, Michiko, Tanaka, Erina, Nishioka, Masahiro, Sato, Yusuke, Sakai, Yukiko, Maehata, Takaharu, Furuta, Toshihiko, Yasui, Yoshihiro, Yano, Takuya, Tanino, Asa, Hirata, Sachi, Nagasao, Akiko, Hiroi, Satoshi, Kubo, Hideyuki, Okayama, Fumika, Oshibe, Tomohiro, Mori, Ai, Murayama, Ryutaro, Chiba, Shoko, Matsui, Yuki, Kiguchi, Yuko, Takeuchi, Koji, Mita, Tetsuo, Nomiya, Kayoko, Shimazu, Yukie, Fujii, Yoshiki, Toda, Shoichi, Kawakami, Yumiko, Terajima, Yukari, Yamashita, Mayumi, Takahashi, Tomiyo, Ashizuka, Yuki, Wasano, Chinami, Kimura, Takashi, Moroishi, Sanae, Urakawa, Miho, Sakai, Takashi, Nishizawa, Kaori, Hayashi, Toru, Matsuura, Yu, Hamada, Yuka, Kuba, Yumani
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.08.2020
• Subjects: Baloxavir; Cap-dependent endonuclease inhibitor; Influenza; Resistance; Resistance; Cap-dependent endonuclease inhibitor; Influenza; Baloxavir
• ISSN: 0166-3542; 1872-9096
• DOI: 10.1016/j.antiviral.2020.104828

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. •Influenza A(H1N1)pdm09 virus carrying a PA E23K substitution was detected.•The PA E23K mutant virus showed reduced baloxavir susceptibility.•The PA E23K mutant virus was isolated from a child without baloxavir treatment.•Possible transmission of the PA E23K mutant virus among humans is suggested.•Baloxavir susceptibility monitoring of influenza viruses is essential.