“The scientists found that aerosol exposure directly deposited SARS-CoV-2 deep into the lungs, whereas fomite [surface] exposure resulted in initial virus replication in the nose. Regardless of exposure route, animals had SARS-CoV-2 replicating in the lungs, but lung damage was more severe in aerosol-exposed animals compared to the fomite group,” an NIH press release said.
To investigate how different routes of exposure affected disease development, the scientists exposed hamsters to SARS-CoV-2 via both aerosols and fomites. For aerosol exposure, the scientists used equipment that controlled the size of virus-loaded droplets. For fomite exposure, they placed a dish contaminated with SARS-CoV-2 in the animal cages, the release explained.
The experiments also showed that virus transmission from contaminated surfaces is markedly less efficient than with airborne exposure, although surface transmission does occur, the release added.
The findings support public health guidance focused on interventions to reduce indoor airborne transmission of SARS-CoV-2. The efforts include masking, increasing air filtration and social distancing, in addition to steps reducing surface transmission such as handwashing and regular surface disinfection, according to the release.
The release summarized a report by scientists from the NIH’s National Institute for Allergy and Infectious disease that was published in the journal Nature Communications.