Persistent viral shedding of SARS-CoV-2 in faeces - a rapid review

Gupta, Sunnia; Parker, Jody; Smits, Stephanie; Underwood, Jonathan; Dolwani, Sunil

Background and aims In addition to respiratory symptoms, patients with COVID-19 can present with gastrointestinal complaints suggesting a possible faeco-oral transmission route. The primary aim of this review is to establish the incidence and timing of positive faecal samples for the SARS-CoV-2 virus in patients with COVID-19. Methods A systematic literature review was performed to identify studies describing COVID-19 patients tested for the virus in their stool. Data were extracted concerning the nature of the test, number and timing of positive samples, incidence of positive faecal tests after negative nasopharyngeal swabs and any evidence of viable faecal virus or faeco-oral transmission of the virus. Results There were 26 relevant articles identified. Combining these results demonstrated that 53.9% of those tested for faecal RNA in these studies were positive. Duration of faecal viral shedding ranged from 1 to 33 days after nasopharyngeal swab turned negative with one result remaining positive after 47 days of onset of symptoms. There was insufficient evidence to draw firm conclusions about the proportion of cases potentially transmitted through infection via faecally shed virus. Conclusions There is a relatively high rate of positive tests and persistence of the SARS-CoV-2 virus in faecal samples of selected patients with COVID-19. Further research is needed to demonstrate how much these positive tests correlate with viable virus and transmission through the faeco-oral route. This may have important implications for duration of isolation, precautions recommended in individuals undertaking a period of isolation, protective equipment for health professionals and interventional procedures involving the gastrointestinal tract.