Coronavirus could rise up through toilet pipes: Traces of SARS-CoV-2 found in unoccupied apartment

Researchers found traces of coronavirus in the bathroom of an unoccupied apartment, which was directly above the home of five people who tested COVID positive.

The novel coronavirus is turning out to be more powerful than what researchers had earlier thought. Initially, it was believed that the virus spreads mainly through respiratory droplets released when an infected person sneezes, coughs or speaks. Later scientists found that the deadly virus is airborne, and it is present in tiny droplets called aerosols that waft through the air. There is another concern for people living in apartments in multistory buildings that have a shared wastewater system. Now, Chinese researchers claim that SARS-CoV-2, which is responsible for the ongoing COVID-19 pandemic, could spread through toilet pipes.

They made the claim after they found traces of coronavirus in the bathroom of an unoccupied apartment in Guangzhou, China. This surprising discovery indicated that the virus may have wafted upwards through drain pipes via tiny airborne particles that can be created by the force of a toilet flush. This is reminiscent of a large SARS outbreak in Hong Kong 17 years ago.

Coronavirus found in a vacant Chinese apartment

Traces of SARS-CoV-2 were found in February on the sink, faucet and shower handle of a long-vacant apartment, which was directly above the home of five people who tested COVID positive a week before.

Researchers at the Chinese Center for Disease Control and Prevention (CDC) announced this startling discovery in a paper published this month in Environment International.

They found SARS-CoV-2-laden aerosols (tiny airborne particles) in bathrooms 10 and 12 levels above the COVID-19 cases. The researchers suggested that the virus in the stool of Covid-19 patients could have drifted into these homes via plumbing.

The researchers compared this event with the Amoy Gardens SARS outbreak in Hong Kong in 2003. In the earlier case, 329 residents of the Amoy Gardens private housing estate caught severe acute respiratory syndrome, or SARS, apparently due to faulty sewage pipelines and a many as 42 residents died. This was believed to the most devastating community outbreak of SARS, which is also caused by a coronavirus.

COVID-19 virus may spread from the stool of patients

Since the very beginning of the pandemic, scientists in China have been suggesting that the infectious virus present in the stool of Covid-19 patients may also play a role in transmission. In February, a study revealed that many COVID-19 patients in Guangdong province tested positive for the virus in their stool.

Another research recently indicated that toilet flushes can generate germ-laden aerosols from the excreta. The researchers claimed that these particles can remain in the air for long periods and be dispersed over distances of more than 1 meter (3 feet), particularly in confined, poorly ventilated spaces.

Based on their findings, the China CDC researchers said that toilets may promote fecal-derived aerosol transmission if used improperly, particularly in hospitals.

In a fluid-dynamics simulation, they also observed a "massive upward transport of virus aerosol particles" during flushing, leading to large-scale virus spread indoors.

Several studies have also found SARS-CoV-2 genetic material on toilets used by Covid-19 patients, in the air in hospitals, air outlet vents, and multiple other sites. However, the extent to which germ-laden fecal aerosol plumes are infecting people isn't clear yet.