23 Jun 2021
Researchers investigate the role of faecal-oral transmission of COVID-19
Peer review: Infection Control and Hospital Epidemiology
Funding: APPRISE, Jack Ma Foundation, a2 Milk Company and Snow Medical Foundation
Doherty Institute researchers have reported evidence of live SARS-CoV-2 being found in faecal samples of a patient with mild to moderate COVID-19.
Part of the Sentinel Travelers Research Preparedness Platform for Emerging Infectious Diseases (SETREP-ID) project, this case study collected nasal pharyngeal, sputum, blood and faecal samples from a hospitalised patient in 2020.
SETREP-ID was established in 2017 by the Doherty Institute’s Dr Irani Thevarajan, an Infectious Diseases Physician with the Royal Melbourne Hospital’s Victorian Infectious Diseases Service to enable collection of biological samples in returned travellers in the event of a new and unexpected infectious disease outbreak.
In this instance, the team looked at whether virus was detectable by PCR test, and able to be grown in culture in a laboratory, as well as antibody levels, over six different time points, with a view to establishing transmission routes of COVID-19. The findings were published in Infection Control and Hospital Epidemiology.
First author on the paper, Dr Jennifer Audsley, Clinical Research Fellow at the Doherty Institute said there has been some debate as to whether virus detected in stool samples is a result of virus being ingested via respiratory secretions, or the virus replicating in the gastrointestinal tract, and whether that virus is still infectious.
“What we found with this case study, is that we were able to isolate the virus from the faecal samples much later than the respiratory samples. It was day nine of the infection that we were able to detect live virus from the faecal sample, but by then it was no longer viable in the respiratory sample,” Dr Audsley said.
“While we still can’t answer the question definitively of how much of a role faecal-oral transmission of COVID-19 plays in this pandemic, it certainly shows that further evaluation is needed to gain a better understanding of COVID-19 transmission dynamics.”
Separate to the investigation of COVID-19 transmission, the team utilised the samples to explore the immune response of this patient – who was also HIV positive, in an effort to understand the interaction of HIV and COVID-19.
“We found that this patient elicited a robust immune response to COVID-19 with broad immune activation,” Dr Audsley said.
This work was supported by funds from the Australian Partnership for Preparedness Research on Infectious Disease Emergencies (APPRISE) funds, a2 Milk Company and the Jack Ma Foundation. Ongoing follow-up is supported by the Snow Medical Foundation.