Can viral material from the COVID-19 infection be found in fecal samples, and if so, how long does it remain for?

Bottom Line:

Viral material from the SARS-CoV-2 virus has been found in fecal samples of patients with the COVID-19 infection, lasting up to 5 weeks following clearance of their respiratory tract infection. This poses a concern of potential fecal-oral transmission and reinforces strict precautions to prevent further transmission, especially in dense, contained areas.

Reference:

Wu, Y. et al. Prolonged presence of SARS-CoV-2 viral RNA in faecal samples. The Lancet Gastroenterology & Heptaology (2020). https://doi.org/10.1016/S2468-1253(20)20083-2

Date Published:

13 March 2020

Synopsis:

Although the primary path of infection for COVID-19 is through the respiratory system, it is important to screen for alternative transmission routes to reduce further spreading of the virus. In the study, 41 individuals from a cohort of 74 patients with COVID-19 had fecal samples positive for the virus. Analyses from those fecal samples showed that the viral particles remained present for an average of four weeks. Both gastrointestinal symptoms and overall disease severity did not correlate with fecal viral presence while anti-viral treatment showed a positive trend with fecal viral positivity. More research is required to make causal conclusions. Evidence further suggested that the virus still actively replicates in the digestive tract even after the respiratory tract clears, suggesting concerns for possible viral transmissions. That said, viral detection in feces is generally delayed, and so additional testing on top of existing diagnostic procedures that would reduce medical resources is not considered necessary. Instead, these results underline the importance for stricter precautions and should reinforce sanitary habits in areas of close proximity, such as: buses, hostels, dormitories, and cruise ships. However, no cases yet have been linked to fecal-oral transmissions. Still, more research is required to further understand the viral viability in fecal matter, and how infectious the particles are in stool samples.

Summary by: Edwin Wong