Researchers in the UAE have begun tracking the virus that causes Covid-19 in local wastewater to predict the spread of the disease among the population.
Studies have shown people infected with the virus, even those who do not develop symptoms, shed it through their excrement.
And because levels of Sars-Cov-2 would be expected to mirror the prevalence of infections in the population, experts have said studying wastewater would give authorities an indication of how widespread the virus was in the community.
Khalifa University, which is conducting the research, said it would be “tantamount to essentially testing everyone who has contributed to that sample - in other words a way of mass testing”.
The study is expected to help scientists construct a model that estimates the total number of symptomatic and asymptomatic people in the population, based on the levels of the virus found in wastewater.
Studies have shown viral shedding happens early in the progression of the disease, well before people develop symptoms.
That led researchers around the world to hypothesise that it may show up in a city’s wastewater before people tested positive for the virus.
Experts at KWR Water Research Institute in the Netherlands began testing samples in February working on that assumption, before the country had identified any cases.
Writing on its website, the company said it tested the samples using the same method used on swabs taken from people, which searched for the presence of specific genetic material of the virus.
And they found that as the first cases emerged and began to spread, the viral concentration in the sewer increased in step.
None of the first tests showed a reaction in February. By March 5, on the second sweep, samples at four waste water treatment suggested the virus could be present. And by March 15, when the third samples were taken, the reaction was stronger.
“The results indicate that SARS-CoV-2 is present in sewage water,” said the company.
“Our sewage screening can help to get a better picture of the virus circulation. When the current peak (hopefully it will stay as flat as possible) is over, sewage screening also helps to detect early – possibly coming winter – if the virus circulation is increasing.”
Other researchers in the United States and elsewhere are looking into the same issue, but have not released any findings as yet.
Khalifa University’s project involved researchers from the university’s Centre for Biotechnology and the Centre for Membranes and Advanced Water Technology, alongside experts from across the university, including Dr Ahmed Yousef, assistant professor, Chemistry, as well as Dr Shadi Hasan, associate professor, chemical engineering, and others.
“Through this research, Khalifa University aims to establish a surveillance system for Covid-19 in municipal wastewater streams, linking it with simulation models developed for predicting and controlling the spread of the pandemic, together with the health authorities,” said Dr Arif Al Hammadi, executive vice-president, Khalifa University.