SARS-CoV2 transmission by aerosol in Syrian hamsters

The global SARS-CoV2 pandemic has brought many aerosol transmission questions to the forefront of respiratory research. While methods for non-clinical transmission have been characterized for flu little is known with SARS-CoV2. Therefore, a non-clinical model was developed in the Syrian hamster, a well characterized system for studying SARS-CoV-2. The standard method to challenge the hamster is with intranasal installation, which results signs of disease similar to clinical cases . The disease progresses over 5 -8 days and includes body weight loss, increase in lung weight (due to edema and cellular infiltrates), and viral load (measured via nasal swabs and lung tissue with PCR and TCID50). In order to establish a model of aerosol transmission systems were developed with one directional air flow chamber where an infected (index) animal is housed upstream of recipient (naive) animals, separated by a connection chamber. Animals are completely separated from contact and the system design also prevents transmission from fomites such as bedding, feed, and excreta. During exposures, aerosols in the connection chamber were monitored via filter samples (glass fiber (GF/A) for total concentration, membrane (PES for mRNA) and with all glass impingers. PCR analysis of the aerosols showed that one infected hamster can generate an aerosol concentration of SARS-CoV2 was ∼940 viral genomes per liter of air. Through aerosol transmission, naive hamsters became infected with SARS-CoV-2, lost weight, had pulmonary inflammation, and importantly showed viral replication in the lungs. With additional confirmation testing this model will be appropriate for the evaluation of vaccines, and prophylactic and therapeutic interventions to prevent SARS-CoV2 transmission.