Oral SARS-CoV-2 Inoculation Establishes Subclinical Respiratory Infection with Virus Shedding in Golden Syrian Hamsters

Abstract

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.

Immunological and cardio-vascular pathologies associated with SARS-CoV-2 infection in golden syrian hamster

“…Further, a decrease in body mass had been reported in the initial phase of SARS-CoV2 infection. Inline, intranasal SARS-CoV2 infection in GSH showed a gradual body mass loss peaking (~10% as compared to uninfected) at 4 dpi with 10 4 and 10 5 plaque-forming unit (PFU) ( Figure 2A ) (Chan et al, 2020; Imai et al, 2020; Lee et al, 2020; Sia et al, 2020). This was accompanied by gross lung morphological changes characterized by pneumonitis regions with a high viral dose 10 5 (PFU).…”

“…SARS-CoV2 is inefficient in infecting mice due to structural differences in mouse ACE2 as compared to human ACE2, thus wild type mice are not the natural host to study SARS-CoV2 induced pathologies (Bao et al, 2020, p. 2; Chan et al, 2020). On the other hand, GSH, which was previously described as a model for SARS-CoV infection, has recently gained much attention as a suitable model for studying SARS-CoV2 infection (Chan et al, 2020; Imai et al, 2020; Kaptein et al, 2020; Kreye et al, 2020; Lee et al, 2020; Osterrieder et al, 2020; Sia et al, 2020; Tostanoski et al, 2020). Remarkably, hamsters have been shown to be infected through intranasal, oral and ophthalmic routes by SARS-CoV2 with respectively descending lung viral load and pathologies (Imai et al, 2020; Lee et al, 2020).…”

“…On the other hand, GSH, which was previously described as a model for SARS-CoV infection, has recently gained much attention as a suitable model for studying SARS-CoV2 infection (Chan et al, 2020; Imai et al, 2020; Kaptein et al, 2020; Kreye et al, 2020; Lee et al, 2020; Osterrieder et al, 2020; Sia et al, 2020; Tostanoski et al, 2020). Remarkably, hamsters have been shown to be infected through intranasal, oral and ophthalmic routes by SARS-CoV2 with respectively descending lung viral load and pathologies (Imai et al, 2020; Lee et al, 2020). Despite several reports on hamsters describing the SARS-CoV2 pathology in the lung and pre-clinical evaluation of therapeutics against it, no study has focused on extra-pulmonary pathologies that are associated with long-term consequences of SARS-CoV2 infection.…”

New Insights Into the Physiopathology of COVID-19: SARS-CoV-2-Associated Gastrointestinal Illness

“…ACE2 was also reported on the epithelial cells of the oral mucosa ( 90 ). Using a Syrian Hamster animal model of SARS-CoV-2 infection, it was recently reported that oral inoculation of SARS-CoV-2 established mild pneumonia in 67% of animals exposed to the virus and caused intestinal inflammation ( 91 ). The expression of ACE2 on enterocytes of the small intestine was reported by Hamming et al ( 88 ), with the highest expression found in the brush border of intestinal enterocytes ( 92 , 93 ), the main role of which is to ensure the absorption of nutrients.…”

Examining the persistence of human Coronavirus 229E on fresh produce

“…Moreover, persistent fecal viral shedding has been observed in pediatric patients ( Xu et al, 2020a , b ) and there is evidence that SARS-CoV-2 can replicate productively in human enteroids and enterocytes ( Lamers et al, 2020 ; Zhou et al, 2020 ). More recently, it was demonstrated that multi-route mucosal inoculation (including oral inoculation) of African green monkeys with SARS-CoV-2 results in infection in both the respiratory and gastrointestinal tract ( Hartman et al, 2020 ), and orally inoculated golden Syrian hamsters develop respiratory and intestinal infection ( Chak-Yiu Lee, et al 2020 ). Collectively, these observations suggest that fecal-oral transmission of SARS-CoV-2 is possible.…”