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Reduction in SARS-CoV-2 Virus Infectivity in Human and Hamster Feces
Sébastien Wurtzer1, Sandra Lacote2, Severine Murri2
1Research and Development Department, Eau de Paris, 33 Avenue Jean Jaurès, 94200 Ivry-sur-Seine, France.
Objective:
There is extensive evidence that SARS-CoV-2 replicates in the gastrointestinal tract. However, the infectivity of virions in feces is poorly documented. Although the primary mode of transmission is airborne, the risk of transmission from contaminated feces remains to be assessed.
Design:
The persistence of SARS-CoV-2 (infectivity and RNA) in human and animal feces was evaluated by virus isolation on cell culture and RT-qPCR, respectively. The exposure of golden Syrian hamsters to experimentally contaminated feces through intranasal inoculation has also been tested to assess the fecal-oral transmission route.
Results:
For periods that are compatible with average intestinal transit, the SARS-CoV-2 genome was noticeably stable in human and animal feces, contrary to the virus infectivity that was reduced in a time- and temperature-dependent manner. In human stools, this reduction was variable depending on the donors. Viral RNA was excreted in the feces of infected hamsters, but exposure of naïve hamsters to feces of infected animals did not lead to any productive infection. Conversely, hamsters could be experimentally infected following exposure to spiked fresh feces.
Conclusion:
Infection following exposure to naturally contaminated feces has been suspected but has not been established so far. The present work demonstrates that SARS-CoV-2 rapidly lost infectivity in spiked or naturally infected feces. Although the possibility of persistent viral particles in human or animal feces cannot be fully ruled out, SARS-CoV-2 transmission after exposure to contaminated feces is unlikely.
Insights
SARS-CoV-2 RNA is stable in feces, but the virus rapidly loses infectivity. Transmission of SARS-CoV-2 via contaminated feces is unlikely, despite viral RNA presence in animal stool.
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.
