Reduction in SARS-CoV-2 Virus Infectivity in Human and Hamster Feces

Area of Science:

• Virology
• Gastroenterology
• Infectious Diseases

Background:

• Extensive evidence confirms SARS-CoV-2 replication within the gastrointestinal tract.
• The infectivity of SARS-CoV-2 virions present in feces remains inadequately documented.
• Assessing the risk of fecal-oral transmission is crucial, though airborne transmission is primary.

Purpose of the Study:

• To evaluate the persistence and infectivity of SARS-CoV-2 in human and animal feces.
• To determine the potential for fecal-oral transmission of SARS-CoV-2.
• To assess the stability of viral RNA and infectivity over time in fecal matter.

Main Methods:

• Virus isolation on cell culture to assess infectivity.
• RT-qPCR to quantify viral RNA.
• Intranasal inoculation of golden Syrian hamsters with contaminated feces to test transmission routes.

Main Results:

• SARS-CoV-2 genome remained stable in feces for periods consistent with intestinal transit.
• Viral infectivity decreased in a time- and temperature-dependent manner, with variability in human stools.
• Infected hamsters excreted viral RNA, but direct transmission from their feces to naive hamsters was not observed; however, experimental infection occurred with spiked feces.

Conclusions:

• SARS-CoV-2 rapidly loses infectivity in both spiked and naturally contaminated feces.
• While persistent viral particles cannot be entirely excluded, transmission of SARS-CoV-2 through contaminated feces is improbable.
• The study highlights the reduced infectivity of SARS-CoV-2 in fecal matter, suggesting a low risk of fecal-oral transmission.