Scientists isolate live COVID-19 virus from faeces, detect RNA on surfaces
Two new Chinese studies have added further evidence to the likelihood of faecal-oral and fecal-respiratory transmission of COVID-19, as well as shedding new light on surface transmission.
The first study began with analysis of an elderly man who was hospitalised, intubated and eventually died in Guangzhou, China. Fecal samples taken from the patient contained SARS-CoV-2 RNA, and transmission electron microscopy showed viral particles visually similar to SARS-CoV-2.
The researchers then took fecal samples from 27 other patients. 11 of these tested positive to viral RNA once or more, and live SARS-CoV-2 was isolated in two samples.
From these findings, as well as previous research on SARS-CoV-1, the authors concluded that faecal-oral or faecal-respiratory transmission through aerosolised faeces was possible. To avoid spread via this vector, they recommended hospitals should clean surfaces more thoroughly than usual after the discharge or death of a critically ill patient.
The second study was into contamination of surfaces by two presymptomatic Chinese students who were quarantined in hotel rooms on return to China earlier this year.
22 surfaces were tested across the two rooms shortly after the students began showing symptoms, with 36% of these testing positive for SARS-CoV-2 RNA.
Although the researchers noted that they didn’t isolate live virus from the samples, they claimed the results to be strong evidence of the potential for presymptomatic patients to quickly contaminate environments due to high viral load shedding.
Particularly high viral loads were found in the sheets and pillowcases of the two students, leading the researchers to recommend that bedding of those confirmed to have COVID-19 not be shaken out, but instead thoroughly cleaned and dried before reuse.