June 23, 2021
Doherty Institute researchers have reported evidence of live SARS-CoV-2 in faecal samples of a person with mild-to-moderate COVID-19.
Part of the Sentinel Travellers Research Preparedness Platform for Emerging Infectious Diseases (SETREP-ID) project, the researchers collected nasal pharyngeal, sputum, blood and faecal samples from a person hospitalised with COVID-19 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.
To establish potential transmission routes of COVID-19, the team looked at whether virus was detectable by PCR test and whether the virus could be be grown in culture in a laboratory. They also studied antibody levels in the patient over six different time points. 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 about 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, Dr Audsley said the team used the samples to explore the immune response of this person – 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.”
This work was supported by funds from the Australian Partnership for Preparedness Research on Infectious Disease Emergencies (APPRISE), a2 Milk Company and the Jack Ma Foundation. Ongoing follow-up is supported by the Snow Medical Research Foundation.