Coronavirus particles can spread through flushing toilets - study

A new study has revealed coronavirus could spread through the spray from a toilet after a flush releases fecal matter into the air.

The deadly virus has already been proven to live and replicate in the digestive system and evidence of the pandemic has been found in human waste.

Exposure to the waste of an infected person is considered a possible route of transmission, and now a computer modelling study has documented how it can be sent into the air.

The toxic spray can travel as much as 90 centimetres, according to the Physics of Fluids journal from the Yangzhou University in China.

One can foresee that the velocity will be even higher when a toilet is used frequently, such as in the case of a family toilet during a busy time or a public toilet serving a densely populated area, Ji-Xiang Wang of Yangzhou University said in a statement.

Other studies have already discussed how the “toilet plume” aerosols created from a flush can spread other infectious viruses such as norovirus, which causes vomiting and diarrhoea.

And the University of Washington School of Medicine wrote in April this year the toilet is a likely source of coronavirus contamination.

Already, evidence of SARS-CoV-2 contamination of surface and air samples outside of isolation rooms, and experimental data showing that SARS-CoV-2 can live in aerosols for three hours, should raise concerns about this mode of transmission and prompt additional research, according to the university’s Carmen McDermott who wrote in the Journal of Hospital Infection.

Fecal shedding seems to occur in patients without gastrointestinal symptoms, which could enable asymptomatic individuals with no respiratory symptoms to be a source of fecal transmission.

An aerosol expert at Britain’s University of Bristol, Bryan Bzdek, said the chance of infection through flushing made sense, according to CCN.

The viral load in fecal matter and the fraction of resulting aerosol containing the virus is unknown. Even if the virus were contained in the produced aerosols, it is unknown whether the virus would still be infectious; there is not yet clear evidence for fecal-oral transmission, he said.

The study authors suggest that whenever possible we should keep the toilet seat down when we flush, clean the toilet seat and any other contact areas frequently, and wash our hands after using the toilet. While this study is unable to demonstrate that these measures will reduce transmission of the SARS-CoV-2 virus, many other viruses are transmitted though the fecal-oral route, so these are good hygiene practices to have anyway.