key: cord-0754332-hi9sj0d7
authors: Ng, Siew C; Chan, Francis K L; Chan, Paul K S
title: Screening FMT donors during the COVID-19 pandemic: a protocol for stool SARS-CoV-2 viral quantification
date: 2020-04-22
journal: Lancet Gastroenterol Hepatol
DOI: 10.1016/s2468-1253(20)30124-2
sha: cbf903a6be9eebdbb45acae15e2309a0d67be95e
doc_id: 754332
cord_uid: hi9sj0d7

nan

We read with interest the Correspondence by Christopher Green and colleagues 1 suggesting the need for a molecular test to screen faecal microbiota transplant (FMT ) donors for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to prevent the potential risk of transmission. On March 12, 2020, the US Food and Drug Administration (FDA) issued safety alerts because of a death caused by transmission of drug-resistant Escherichia coli bacteraemia via FMT. 2 With more than 1 million people infected by SARS-CoV-2, screening policies for FMT donors should be stringent and scientifically validated. The presence of SARS-CoV-2 (including live virus) in stool of asymptomatic individuals implies that coronavirus disease 2019 (COVID-19) might be transmitted via the faecal route. 3, 4 Development of stool tests has been slow, since realtime RT-PCR of respiratory samples is typically used to confirm the diagnosis of COVID-19.

At the time of writing, the FDA recommends that only FMT products generated from stool donated before Dec 1, 2019, should be used until proper testing and screening protocols are available. 5 As described by Green and colleagues, 1 the University of Birmingham Microbiota Treatment Centre (Birmingham, UK) is not actively processing new donors until a validated SARS-CoV-2 stool test is available. The FMT centre at the Chinese University of Hong Kong (Hong Kong) is one of the largest providers of FMT in Asia and is the sole provider of FMT to the Health Authority of Hong Kong. Although the first case of COVID-19 was reported in Hong Kong on Jan 22, 2020, we quarantined all donor material donated since Nov 1, 2019, from use. We developed a screening protocol that combines a questionnaire to identify donors who might be at risk of SARS-CoV-2 infection with an RT-PCR assay for detecting SARS-CoV-2 in donor stool. The assay (panel) allows SARS-CoV-2 viral quantification with a 3 h turnaround. We validated the assay in 81 stool samples from 21 confirmed SARS-CoV-2 cases and 114 stool samples from 114 asymptomatic non-infected individuals who had returned from high-risk areas. As per the diagnostic protocol of our local health authority, all COVID-19 cases had been confirmed by two RT-PCR tests targeting different regions of the RdRp gene in respiratory specimens. All 21 confirmed cases had positive stool tests (median two stool samples positive for SARS-CoV-2 per patient; viral load 2·9-7·1 log 10 copies per mL). No stool samples from the 114 asymptomatic individuals tested positive for SARS-CoV-2.

We found that a single negative test, as in the current practice for screening other pathogens, is insufficient to exclude the presence of SARS-CoV-2 in stool. We recommend testing donors at multiple timepoints during the donation period, since the level of viral RNA present in stool can fluctuate around the margin of laboratory detection. Testing stool for SARS-CoV-2 should be done in appropriately equipped laboratories by trained staff; specimen handling would require biosafety level 2 laboratories or equivalent facilities.

Only with enhanced donor screening and validated stool tests for SARS-CoV-2 can we ensure safe and effective delivery of FMT to critically ill patients with recurrent and refractory Clostridioides difficile infection. 

Screening faecal microbiota transplant donors for SARS-CoV-2 by molecular testing of stool is the safest way forward

Drug-resistant E coli bacteremia transmitted by fecal microbiota transplant

Virological assessment of hospitalized patients with COVID-2019

Detection of SARS-CoV-2 in different types of clinical specimens

Safety alert regarding use of fecal microbiota for transplantation and additional safety protections pertaining to SARS-CoV-2 and COVID-19