Human-to-Human Transmission of Influenza A(H3N2) Virus with Reduced Susceptibility to Baloxavir, Japan, February 2019

• Published in: Emerging infectious diseases Vol. 25; no. 11; pp. 2108 - 2111
• Main Authors: Takashita, Emi, Ichikawa, Masataka, Morita, Hiroko, Ogawa, Rie, Fujisaki, Seiichiro, Shirakura, Masayuki, Miura, Hideka, Nakamura, Kazuya, Kishida, Noriko, Kuwahara, Tomoko, Sugawara, Hiromi, Sato, Aya, Akimoto, Miki, Mitamura, Keiko, Abe, Takashi, Yamazaki, Masahiko, Watanabe, Shinji, Hasegawa, Hideki, Odagiri, Takato
• Format: Journal Article
• Language: English
• Published: United States U.S. National Center for Infectious Diseases 01.11.2019; Centers for Disease Control and Prevention
• Subjects: Adolescent; Adult; antimicrobial resistance; Antiviral Agents - pharmacology; Antiviral Agents - therapeutic use; baloxavir acid; Baloxavir marboxil; cap-dependent endonuclease inhibitor; Child; Clinical trials; Disease Susceptibility; Dispatch; drug resistance; Genes; Genomes; Genomics; Humans; Infant; Infection; Influenza; Influenza A Virus, H3N2 Subtype - drug effects; Influenza A Virus, H3N2 Subtype - genetics; influenza virus; Influenza viruses; Influenza, Human - drug therapy; Influenza, Human - epidemiology; Influenza, Human - transmission; Influenza, Human - virology; Japan - epidemiology; Laninamivir; Middle Aged; Mutation; Nucleases; Oxazines - pharmacology; Oxazines - therapeutic use; Peramivir; Pyridines - pharmacology; Pyridines - therapeutic use; Thiepins - pharmacology; Thiepins - therapeutic use; Triazines - pharmacology; Triazines - therapeutic use; Young Adult; Japan; influenza; viruses; Japan; whole-genome sequencing; baloxavir; H3N2; respiratory infections; influenza A(H1N1)pdm09; baloxavir marboxil; I38T substitution; antimicrobial resistance; polymerase acidic; family cluster; influenza virus; cap-dependent endonuclease inhibitor; baloxavir acid; human-to-human transmission
• ISSN: 1080-6040; 1080-6059; 1080-6059
• DOI: 10.3201/eid2511.190757

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.