COVID-19 transmission could be through sewage system, warn environmental biologists

As the battle against coronavirus outbreak continues, a study by environmental biologists' hint at dangers from the potential spread of COVID-19 through sewage. The scientists believe that importance should be given to prevent transmission from wastewater in an attempt to curb the pandemic.

So far, the majority of preventive measures to slow down the spread of pandemic disease, a deadly respiratory illness that is caused by SARS-CoV-2, focused on person-to-person transmission. However, as per a new study by the researchers of the University of Stirling that sewage "must not be neglected" in the fight against the global pandemic.

According to the news release on Stirling University's official website, Professor Richard Quilliam, the author of the paper, highlights the "environmental implications of shedding" of the virus in human faeces. The findings warn against the transmission risk posed by the sewer system.

The study urges authorities to turn their attention towards sewer systems as a potential source of bacteria and viruses "widespread." The findings of the peer-reviewed study are supported by the example of the severe acute respiratory syndrome (SARS) outbreak in 2002-2003 when SARS-CoV-1 was detected in sewage discharge by two hospitals in China.

"We know that COVID-19 is spread through droplets from coughs and sneezes, or via objects or materials that carry infection. However, it has recently been confirmed that the virus can also be found in human faeces – up to 33 days after the patient has tested negative for the respiratory symptoms of COVID-19," Quilliam said in the statement.

Nevertheless, the professor points out that there is no evidence of viruses spread through faeces. However, viral shedding through the digestive system is considered more harmful.

"It is not yet known whether the virus can be transmitted via the fecal-oral route, however, we know that viral shedding from the digestive system can last longer than shedding from the respiratory tract. Therefore, this could be important – but as yet unquantified – a pathway for increased exposure," Quilliam added.

As per the study, the risk of coronavirus spread increases in the parts of the world with poor sanitation systems and weak healthcare systems.

The findings of the £1.85 million study led by Quilliam and Professor Manfred Weidmann, Dr Vanessa Moresco, Heather Purshouse, Dr Zoe O'Hara, and Dr David Oliver was published in journal Environment International. The group of biologists is now calling for "an investment of resources" to investigate their concerns.

The paper concludes "in the immediate future, there needs to be an investment of resources to improve our understanding of the risks associated with the faecal transmission of SARS-CoV-2, and whether this respiratory virus can be disseminated by enteric transmission. Understanding the risk of spread via the fecal-oral route, while still at a fairly early stage of the pandemic, will allow more evidence-based information about viral transmission to be shared with the public."