Influenza A virus is transmissible via aerosolized fomites

Abstract

Influenza viruses are presumed, but not conclusively known, to spread among humans by several possible routes. We provide evidence of a mode of transmission seldom considered for influenza: airborne virus transport on microscopic particles called "aerosolized fomites." In the guinea pig model of influenza virus transmission, we show that the airborne particulates produced by infected animals are mainly non-respiratory in origin. Surprisingly, we find that an uninfected, virus-immune guinea pig whose body is contaminated with influenza virus can transmit the virus through the air to a susceptible partner in a separate cage. We further demonstrate that aerosolized fomites can be generated from inanimate objects, such as by manually rubbing a paper tissue contaminated with influenza virus. Our data suggest that aerosolized fomites may contribute to influenza virus transmission in animal models of human influenza, if not among humans themselves, with important but understudied implications for public health.

SARS-CoV and SARS-CoV-2 are transmitted through the air between ferrets over more than one meter distance

“…Although the current transmission set-up was designed to prevent spill-over of large pieces like food and feces from donor to recipient cages, smaller particles such as aerosolized fur or dust from the carpet tiles in the cages, could potentially still be transmitted to the recipient cage. This has very recently been demonstrated in the guinea pig model where a virus-immune animal, whose body was contaminated with influenza virus, transmitted the virus through the air to an indirect recipient animal 11 . Indeed, measurements with an aerodynamic particle sizer in our set-up showed that particles >10 µm were present in the outlet of donor cages, but also at the inlet of the recipient cages, suggesting that despite the distance between the cages, larger particles were carried to the recipient animals due to the high flow rate ( Fig S1).…”

“…Despite the lack of evidence that exposure to SARS-CoV-2 over substantial distances poses a high infection risk, the debate about the potential role of small aerosols and large droplets in SARS-CoV-2 transmission through the air remains. It was recently shown for influenza virus in the guinea pig model that virus transmission through the air is also possible via aerosolized fomites originating from fur; animals transmitted the virus to 25% of the indirect recipient animals when 10 8 PFU of influenza virus was applied on fur, compared to 88% via airways and fur upon intranasal inoculation 11 . In this study, SARS-CoV RNA was detected on fur swabs from four out of four donor animals but no infectious virus was isolated.…”

Anti-Influenza Strategies Based on Nanoparticle Applications

“…Here we present different strategies of using NPs to fight influenza virus infection: NPs as immunity-inducing vaccines, NPs used in gene silencing approaches, the use of NPs for drug delivery, and bare NPs which also exhibit anti-influenza properties (Table 1). The IAV genome undergoes two phenomena, antigenic shift and drift, that lead to the occurrence of new strains [5][6][7][8]. Different strains of the IAVs circulate annually as seasonal flus, and some of them can evolve into epidemic or pandemic strains [9].…”

“…Oseltamivir and zanamivir are neuraminidase inhibitors, which blocks the release of the progeny virions (E and F, respectively). Influenza virus life cycle (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11). Interaction between HA and sialic-acid followed by membrane fusion and viral entry to the cell (1).…”

Vaccination strategies on dynamic networks with indirect transmission links and limited contact information

“…This is because infectious particles generated by the infected individual persist in the environment, which can transfer to the visiting susceptible individuals. Indirect transmissions may occur via a fomite (e.g., an object like a doorknob or paper that has been contaminated with infectious virus) [ 21 ] or even by the eventual inhalation of droplet nuclei in the air forming aerosolized fomites (such as microscopic aerosol particles consisting of the residual solid cores of evaporated respiratory droplets) [ 22 ].…”