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Updated: Oct 23, 2025
Live Imaging and Quantification of Viral Infection in K18 hACE2 Transgenic Mice Using Reporter-Expressing Recombinant SARS-CoV-2
Published on: November 5, 2021
SARS-CoV-2 disease severity and transmission efficiency is increased for airborne compared to fomite exposure in
Julia R Port1, Claude Kwe Yinda1, Irene Offei Owusu1
1Laboratory of Virology, Division of Intramural Research, National Institutes of Health, Hamilton, MT, USA.
Abstract:
Transmission of SARS-CoV-2 is driven by contact, fomite, and airborne transmission. The relative contribution of different transmission routes remains subject to debate. Here, we show Syrian hamsters are susceptible to SARS-CoV-2 infection through intranasal, aerosol and fomite exposure. Different routes of exposure present with distinct disease manifestations. Intranasal and aerosol inoculation causes severe respiratory pathology, higher virus loads and increased weight loss. In contrast, fomite exposure leads to milder disease manifestation characterized by an anti-inflammatory immune state and delayed shedding pattern. Whereas the overall magnitude of respiratory virus shedding is not linked to disease severity, the onset of shedding is. Early shedding is linked to an increase in disease severity. Airborne transmission is more efficient than fomite transmission and dependent on the direction of the airflow. Carefully characterized SARS-CoV-2 transmission models will be crucial to assess potential changes in transmission and pathogenic potential in the light of the ongoing SARS-CoV-2 evolution.
Insights
Syrian hamsters infected via intranasal, aerosol, or fomite routes showed distinct SARS-CoV-2 disease patterns. Early shedding correlated with increased severity, highlighting the importance of transmission route characterization.
Area of Science:
- Virology
- Infectious Diseases
- Animal Models
Background:
- SARS-CoV-2 transmission occurs via contact, fomite, and airborne routes.
- The relative importance of these transmission routes is debated.
- Understanding transmission dynamics is crucial for controlling the pandemic.
Purpose of the Study:
- To investigate SARS-CoV-2 susceptibility and disease manifestation in Syrian hamsters via different exposure routes.
- To compare the efficiency of airborne versus fomite transmission.
- To assess the relationship between virus shedding, disease severity, and transmission route.
Main Methods:
- Exposure of Syrian hamsters to SARS-CoV-2 via intranasal, aerosol, and fomite inoculation.
- Assessment of respiratory pathology, virus loads, weight loss, and immune responses.
- Analysis of virus shedding patterns and correlation with disease severity.
- Evaluation of airborne versus fomite transmission efficiency and airflow directionality.
Main Results:
- Syrian hamsters are susceptible to SARS-CoV-2 via intranasal, aerosol, and fomite exposure, with distinct disease outcomes.
- Intranasal and aerosol routes led to severe respiratory pathology, higher viral loads, and significant weight loss.
- Fomite exposure resulted in milder disease, characterized by an anti-inflammatory state and delayed shedding.
- Early onset of virus shedding correlated with increased disease severity.
- Airborne transmission was more efficient than fomite transmission and influenced by airflow direction.
Conclusions:
- Different SARS-CoV-2 exposure routes induce distinct disease manifestations and shedding patterns in Syrian hamsters.
- Early virus shedding is a key indicator of disease severity.
- Airborne transmission is more efficient than fomite transmission, with airflow directionality playing a role.
- Well-characterized animal models are essential for studying SARS-CoV-2 evolution and transmission dynamics.
