A Characterization and an Evolutionary and a Pathogenicity Analysis of Reassortment H3N2 Avian Influenza Virus in South China in 2019–2020

Abstract

Seasonal H3N2 influenza virus has always been a potential threat to public health. The reassortment of the human and avian H3N2 influenza viruses has resulted in major influenza outbreaks, which have seriously damaged human life and health. To assess the possible threat of the H3N2 avian influenza virus to human health, we performed whole-genome sequencing and genetic evolution analyses on 10 H3N2 field strains isolated from different hosts and regions in 2019–2020 and selected representative strains for pathogenicity tests on mice. According to the results, the internal gene cassettes of nine strains had not only undergone reassortment with the H1, H2, H4, H6, and H7 subtypes, which circulate in poultry and mammals, but also with H10N8, which circulates in wild birds in the natural environment. Three reassorted strains were found to be pathogenic to mice, of these one strain harboring MP from H10N8 showed a stronger virulence in mice. This study indicates that reassorted H3N2 AIVs may cross the host barrier to infect mammals and humans, thereby, necessitating persistent surveillance of H3N2 AIVs.

Genetic and Biological Characterization of H3N2 Avian Influenza Viruses Isolated from Poultry Farms in China between 2019 and 2021

“…In addition, the internal genes underwent frequent reassortment with multiple subtypes. In general, the internal genes of H3N2 AIVs are similar to those of H1, H4, H5, H6, H7, H10, and H11 subtypes viruses (Figure 2), which are commonly detected in poultry farms and in LPMs [19][20][21]. Genes of H9 subtype viruses were found to be clustered into the same groups formed by the PB2, PA, NP, M, and NS genes of H3N2 AIVs (Figures In summary, the internal genes of the H3N2 AIVs were clustered into groups containing genes from as many as 12 HA subtype viruses, namely, H1, H2, H4, H5, H6, H7, H8, H9, H10, H11, H12, and H14 subtype viruses.…”

“…The H3N2 subtype has been the main subtype circulating in avian species in China [18], and has undergone active reassortment with other influenza virus subtypes in live poultry markets (LPMs) [19][20][21][22], which could generate a virus with pandemic potential. We previously showed that H3N2 AIVs isolated from LPMs have complicated gene constellations, and some isolates can transmit among guinea pigs and ferrets [20].…”

One-Health Challenge in H9N2 Avian Influenza: Novel Human-Avian Reassortment Virus in Guangdong Province, China

“…The time to the most common ancestor was evaluated using the BEAST package (v1.8.4) with the GTR-F-R4 nucleotide substitution model for HA sequences and the GTR-F-R3 nucleotide substitution model for NA sequences and by choosing the appropriate clock model. Markov chain Monte Carlo runs 50 million states with sampling every 5,000 steps, ensuring an effective sample size of more than 200 [26,27]. Each tree ran three times independently and was combined by Log Combiner.…”

“…After a burn-in of 10%, the final tree was summarized using TreeAnnotator. The tree was summed using TreeAnnotator and embellished in FigTree (v1.4.4) software [27].…”

Real-life practice of the Egyptian Kelleni's protocol in the current tripledemic: COVID-19, RSV and influenza

“…Currently, we are dealing in Africa as elsewhere globally, with a tripledemic of SARS CoV-2 Omicron numerous sub-variants, respiratory syncytial virus (RSV), and several influenza viruses including novel 1 and potential reassortment influenza subtypes’ infection 2 , 3 , 4 . The clinical manifestations of these and other respiratory viral infections are mostly similar 5 especially when the patients are seeking an early medical advice as we highly recommended and continue to recommend to be noted that the vast majority of our African patients can't afford to perform any investigations due to economic reasons and again we had to adjust our practice to best serve all patients.…”