Drug resistence and NA gene characteristics of influenza virus A/H1N1(pdm09) studied in Shanghai during 2018-2019

ObjectiveA/H1N1(pdm09) viruses were the dominant strains in Shanghai during 2018-2019 influenza surveillance year.This study is to provide a scientific reference for clinical drug use by investigating the susceptibility of A/H1N1(pdm09) viruses to neuraminidase inhibitors(NAIs).

MethodsSixty strains of A/H1N1(pdm09) viruses were randomly selected for testing the susceptibility and drug resistance to Oseltamivir and Zanamivir by means of neutaminidase inhibition and neuraminidase (NA) gene sequencing.

ResultsThe 60 epidemic strains all proved to be susceptible to Oseltamivir and Zanamivir and the susceptibility was not observed to be decreased or remarkably decreased.In genetic sequencing, NA was not observed to present amino acid mutation at the key sites and auxiliary sites in catalytic activity, which confirmed the results of the phototypic detection of neuraminidase inhibition.

ConclusionThe subtype influenza viruses A/H1N1(pdm09) circulating in Shanghai during 2018-2019 surveillance year are still sensitive to NAIs, which provides a scientific reference for clinical use of drugs.However, we monitored only a number of strains and think that the work monitoring antiviral susceptibility should be continued with the wide use of the drugs.