Sewage monitoring signals early warning of Covid-19 outbreaks

Waste treatment systems should be routinely tested, says NUIG professor

Sligo News File

Consistent surveillance of human waste in sewerage systems “could be the fastest way to identify viruses and bacteria that have the potential to impact large populations,” according to a expert on disease at the National University of Ireland, Galway.

The Irish Times reports Professor Dearbhaile Morris of the NUIG school of medicine as saying that sewage in large cities should be routinely tested to provide an early warning system for future outbreaks of lethal disease and pandemics, and be part of ongoing Covid-19 surveillance.

Her research group works closely with national and international research groups focusing on antimicrobial resistance mechanisms and epidemiology, food and water borne pathogens and other contaminants, and the wider societal impact of infection. 

Cross channel in the UK, a Government-led project is already successfully detecting traces of coronavirus in sewage, and providing an early warning for local outbreaks across the country and sharing date with the NHS Test and Trace.

A press release from the government there states that the programme, first announced in June, has proven that fragments of genetic material from the virus can be detected in wastewater which can then indicate where a local community or an institution is experiencing a spike in cases.

The results, says the statement, can provide local health professionals with a clearer picture of infection rates by identifying where there are high numbers, particularly for asymptomatic carriers and before people start showing symptoms. This will allow local authorities to take early action to slow the spread of the virus.

“The data will be shared with the NHS Test and Trace to inform where new outbreaks may be happening. It means that public health professionals can speak directly to institutions where there may be spikes in infection. Those institutions can in turn encourage people to get tested or take extra precautions.

“The project has already worked successfully in an area in the South West of England where sewage sampling data showed a spike in coronavirus material despite relatively low numbers of people seeking tests.

“This was passed on to NHS Test and Trace and the local council who were able to alert local health professionals to the increased risk and contact people in the area to warn of the increase in cases.

“Testing has now been rolled out across more than 90 wastewater treatment sites in the UK, covering approximately 22% of the population, with plans to expand in the future,” says the statement, issued by the Department for Environment, Food & Rural Affairs, Environment Agency and Department of Health and Social Care.

Professor Morris said that to date in Ireland, surveillance of wastewaters and sewage has been limited to the Dublin and Wicklow areas but in her view “it would be useful to expand this across the country. Results to date show that findings of SARS-CoV-2 in sewage correlate with clinical data.”