Summary Severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) is transmitted largely by respiratory droplets or airborne aerosols. Despite being frequently found in the immediate environment and feces of patients, evidence supporting the oral acquisition of SARS-CoV-2 is unavailable. Using the Syrian hamster model, we demonstrate that the severity of pneumonia induced by the intranasal inhalation of SARS-CoV-2 increases with virus inoculum. SARS-CoV-2 retains its infectivity in vitro in simulated human-fed-gastric and fasted-intestinal fluid after 2 h. Oral inoculation with the highest intranasal inoculum (10 5 PFUs) causes mild pneumonia in 67% (4/6) of the animals, with no weight loss. The lung histopathology score and viral load are significantly lower than those infected by the lowest intranasal inoculum (100 PFUs). However, 83% of the oral infections (10/12 hamsters) have a level of detectable viral shedding from oral swabs and feces similar to that of intranasally infected hamsters. Our findings indicate that the oral acquisition of SARS-CoV-2 can establish subclinical respiratory infection with less efficiency. Graphical Abstract Highlights Oral inoculation of SARS-CoV-2 can establish respiratory infection in hamsters Orally infected hamsters do not have body weight loss and signs of disease Orally infected hamsters have a lower viral load and milder inflammation in lung Orally and intranasally infected hamsters have comparable level of virus shedding Lee et al. demonstrate that SARS-CoV-2 virus can cause subclinical mild pneumonia in Syrian golden hamsters via oral inoculation with less efficiency compared to intranasal inoculation, but virus shedding from oral cavity and feces lasts as long as that in intranasally infected hamsters.
【저자키워드】 COVID-19, SARS-CoV-2, coronavirus, feces, Gastrointestinal, oral, hamster, Subclinical,