Airborne Transmission of Avian Origin H9N2 Influenza A Viruses in Mammals

Abstract

Influenza A viruses (IAV) are widespread viruses affecting avian and mammalian species worldwide. IAVs from avian species can be transmitted to mammals including humans and, thus, they are of inherent pandemic concern. Most of the efforts to understand the pathogenicity and transmission of avian origin IAVs have been focused on H5 and H7 subtypes due to their highly pathogenic phenotype in poultry. However, IAV of the H9 subtype, which circulate endemically in poultry flocks in some regions of the world, have also been associated with cases of zoonotic infections. In this review, we discuss the mammalian transmission of H9N2 and the molecular factors that are thought relevant for this spillover, focusing on the HA segment. Additionally, we discuss factors that have been associated with the ability of these viruses to transmit through the respiratory route in mammalian species. The summarized information shows that minimal amino acid changes in the HA and/or the combination of H9N2 surface genes with internal genes of human influenza viruses are enough for the generation of H9N2 viruses with the ability to transmit via aerosol.

Molecular Evidence of Orthomyxovirus Presence in Colombian Neotropical Bats

“…A detection in bat oropharyngeal swabs, not previously reported, highlights the importance and makes the virological evidence found in the present study another relevant finding, where 60% (6/10) of the positive AIV samples corresponded to oropharyngeal swabs. These results show not only the feasibility of AIV molecular detection in this type of sample but also draw attention to the potential eco-biological consequences that imply, considering the aerosol transmission of influenza viruses ( Cáceres et al, 2021 ) and the relevance and the pivotal role that fruit-eating bats of genus Artibeus sp. could have in AIV eco-epidemiology.…”

The pig as an amplifying host for new and emerging zoonotic viruses

“…Influenza viruses are of worldwide importance, infecting humans, mammalian, and avian species [ 11 , 12 ]. The ability of influenza viruses' segmented genomes to undergo reassortment is a unique trait in which progeny viruses can be produced which have distinctive biological and antigenic characteristics.…”

Influenza antivirals and animal models

“…Outbreaks of HPAIs H5Nx or H7Nx or LPAIVs H9N2 are associated with high mortality, delayed growth, and lower eggs production generating a detrimental effect and economical losses in the poultry industry. Additionally, poultry species play an important role in the generation of novel IAV strains with zoonotic potential [158]. Chickens infected with LPAI typically present mild-to-severe respiratory diseases such as coughing, sneezing, rales, rattles, ocular discharge, decreased activity, mild weight loss, and occasionally diarrhea.…”