Could faecal transmission be behind coronavirus’s rapid spread?
Bloomberg suggest that the fact that the novel coronavirus (COVID-19) is shed in the faeces of infected people may help explain why it is spreading so fast.
Though there is a grain of truth in this, it could be misleading. Despite the fact that live COVID-19 particles have been found in faecal specimens by researchers in China, this is unlikely to be the main way in which this virus spreads.
So far the virus appears to be spread like most other respiratory viruses. Spread to others who come into direct contact with virus-containing droplets generated when an infected person exhales, coughs or sneezes. The virus may also be transmitted via contact with surfaces where droplets have landed such as utensils, clothes, or other surfaces.
Washing hands and avoiding touching your mouth and nose with unclean hands remains the main advice for breaking the transmission of this virus.
Where did the story come from?
The Bloomberg website carried this story on the 20th February.
The story quoted a spokesperson from the Chinese Center for Disease Control and Prevention who said “This virus has many routes of transmission, which can partially explain” its rapid spread.
What is the basis for the claim?
The main evidence behind this story appears to be two recent studies by Chinese researchers (Zhang et al. 2020a and Zhang et al. 2020b). These researchers identified coronavirus genetic material in the faeces of infected patients, and some evidence that live virus was present.
The speed of spread of COVID-19 on a cruise ship (the Diamond Princess) was also cited as showing similarities with norovirus, a tummy bug that causes diarrhoea and vomiting and is spread by the faecal-oral route. Norovirus can survive on surfaces allowing rapid spread of the disease in confined spaces such as cruise ships.
While the evidence suggests that it is possible that coronavirus could spread through the faecal-oral route via contaminated surfaces, without additional corroboration it is probably too soon to imply that this is a major way in which the virus spreads. More research into the possibility of faecal-oral transmission is needed.
What do trusted sources say?
The WHO has confirmed that COVID-19 virus has been detected in respiratory, faecal and blood samples from infected patients.
However, it has reaffirmed that COVID-19 is mainly transmitted via direct contact of virus-containing droplets and people’s eyes, noses or mouths, or contact with objects and surfaces that these droplets land on.
The WHO states that the risk of catching COVID-19 from faeces appears to be low, and the faecal-oral route does not appear to be a driver of COVID-19 transmission at present.
Good hand hygiene will help prevent both droplet transmission and any faecal-oral transmission.
Anaylsis by EIU Healthcare
- Gale J. Bloomberg online: https://www.bloomberg.com/news/articles/2020-02-20/fecal-transmission-may-be-behind-coronavirus-s-rapid-spread. (Accessed March 2, 2020)
- Zhang W, Du R-H, Li B et al. Molecular and serological investigation of 2019-nCoV infected patients: implication of multiple shedding routes. Emerging Microbes & Infections, 2020; 9(1):386-389.
- Zhang Y, Chen C, Zhu S et al. Isolation of 2019-nCoV from a Stool Specimen of a Laboratory-Confirmed Case of the Coronavirus Disease 2019 (COVID-19)[J]. China CDC Weekly, 2020, 2(8): 123-124
- World Health Organization. Report of the WHO-China Joint Mission on Coronavirus Disease 2019 (COVID-19). https://www.who.int/docs/default-source/coronaviruse/who-china-joint-mission-on-covid-19-final-report.pdf (Accessed March 2, 2020)
- World Health Organization. Q&A on coronaviruses (COVID-19). https://www.who.int/news-room/q-a-detail/q-a-coronaviruses (Accessed March 2, 2020)
- Yeo C, Kaushal S, Yeo D. 2020. Enteric Involvement of Coronaviruses: Is Faecal-Oral Transmission of SARS-CoV-2 Possible? The Lancet Gastroenterology & Hepatology. 2020. https://doi.org/10.1016/S2468-1253(20)30048-0. (published February 19, 2020; accessed March 2, 2020).