Influenza A(H3N2) virus exhibiting reduced susceptibility to baloxavir due to a polymerase acidic subunit I38T substitution detected from a hospitalised child without prior baloxavir treatment, Japan, January 2019

  • Euro Surveill. 2019 Mar;24(12):1900170. doi: 10.2807/1560-7917.ES.2019.24.12.1900170.
Emi Takashita  1 ,  Chiharu Kawakami  2 ,  Rie Ogawa  1 ,  Hiroko Morita  1 ,  Seiichiro Fujisaki  1 ,  Masayuki Shirakura  1 ,  Hideka Miura  1 ,  Kazuya Nakamura  1 ,  Noriko Kishida  1 ,  Tomoko Kuwahara  1 ,  Akira Ota  3 ,  Hayato Togashi  3 ,  Ayako Saito  4 ,  Keiko Mitamura  5 ,  Takashi Abe  6 ,  Masataka Ichikawa  7 ,  Masahiko Yamazaki  8 ,  Shinji Watanabe  1 ,  Takato Odagiri  1
Affiliations
  • 1. Influenza Virus Research Center, National Institute of Infectious Diseases, Tokyo, Japan.
  • 2. Yokohama City Institute of Public Health, Kanagawa, Japan.
  • 3. Saiseikai Yokohamashi Nanbu Hospital, Kanagawa, Japan.
  • 4. Saito Children's Clinic, Kanagawa, Japan.
  • 5. Eiju General Hospital, Tokyo, Japan.
  • 6. Abe Children's Clinic, Kanagawa, Japan.
  • 7. Ichikawa Children's Clinic, Kanagawa, Japan.
  • 8. Zama Children's Clinic, Kanagawa, Japan.
PMID: 30914078 DOI: 10.2807/1560-7917.ES.2019.24.12.1900170
Abstract

In January 2019, two influenza A(H3N2) viruses carrying an I38T substitution in the polymerase acidic subunit (PA), which confers reduced susceptibility to baloxavir, were detected from epidemiologically unrelated hospitalised children in Japan. The viruses exhibited reduced susceptibility to baloxavir but were susceptible to neuraminidase inhibitors. Only one of the two children had been treated with baloxavir. An epidemiological analysis suggests possible transmission of the PA I38T mutant A(H3N2) virus among humans.

Keywords
Influenza virus; baloxavir acid; baloxavir marboxil; cap-dependent endonuclease inhibitor; drug resistance.
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