Lack of evidence for infectious SARS-CoV-2 in feces and sewage

Abstract

AbstractPurposeThe SARS-CoV-2 coronavirus is a respiratory virus whose primary route of transmission is airborne. However, it has been shown that the virus can replicate in gastrointestinal cells, can be excreted in feces, and can reach sewage systems. Although viral RNA has been found in patient feces and sewage, little is known about the potential fecal-oral transmission of the coronavirus. Determining the presence of infective viral particles in feces and sewage is necessary to take adequate control measures and to discover new routes of coronavirus transmission.MethodsFeces and urine of COVID-19 patients, and wastewater samples at the time of high prevalence in the region under study (Valencia, Spain), have been analyzed both by molecular methods and cell culture.ResultsPresence of SARS-CoV-2 in feces of COVID-19 patients has been detected, even in patients without gastrointestinal symptoms, suggesting that viral shedding though stool is common. In addition, we have developed a sample concentration methodology that allows us to maintain the infectivity of the viral particles present in the samples. Finally, inoculation of cell cultures with fecal and sewage concentrated samples do not evidence the presence of infective viral particles.ConclusionThere is no evidence of the presence of infectious SARS-CoV-2 in feces and sewage, suggesting that fecal-oral transmission is not a primary route. However, larger-scale efforts are needed to elucidate whether the fecal-oral transmission should be considered, especially with the emergence of new viral variants.