Sato M, Takashita E, Katayose M, Nemoto K, Sakai N. Detection of variants with reduced baloxavir marboxil and oseltamivir susceptibility in children with influenza A during the 2019-2020 influenza season. J Infect Dis. 2021 Apr 10:jiab196
Methods: During the 2019-2020 influenza season, we enrolled children with confirmed influenza A (20 treated with baloxavir and 16 with oseltamivir). We analyzed patients´ sequential viral RNA loads and infectious virus titers, the drug susceptibilities of clinical isolates, and amino acid substitutions in the viral polymerase acidic protein subunits or neuraminidase. We assessed patients´ clinical information using questionnaires.
Results: All viral RNA loads and virus titers were significantly decreased after treatment, but we detected baloxavir-resistant and the oseltamivir-resistant variants in 5 of 20 and 3 of 16 patients, respectively. The duration of fever was similar between patients with and without the variants, but infectious viral shedding lasted 3 days longer in patients with baloxavir-resistant variants. In addition, the duration to improvement of clinical symptoms was longer in these patients (75.0 h vs. 29.5 h; p = 0.106).
Conclusions: After anti-viral treatment, the emergence of baloxavir-resistant variants may affect the patients´ clinical course, but oseltamivir-resistant variants had no clinical impact.
- Genetic characterization and evolution of H6N6 subtype avian influenza viruses 13 hours ago
- A dominant internal gene cassette of high pathogenicity avian influenza H7N9 virus raised since 2018 2 days ago
- A Eurasian avian-like H1N1 swine influenza reassortant virus became pathogenic and highly transmissible due to mutations in its PA gene 3 days ago
- Few Amino Acid Mutations in H6 Influenza A Virus From South American Lineage Increase Viral Replication Efficiency in Poultry 3 days ago
- Monoclonal antibodies targeting the influenza virus N6 neuraminidase 3 days ago