The latest research from the National Institute of Biological Standards and Control (NIBSC) confirms that the testing of wastewater is an effective tool for monitoring coronavirus variants.
Scientists at the Institute have been analysing samples from a London sewage plant since the onset of the pandemic and have previously shown that there is a good correlation between the levels of coronavirus detected in wastewater and the number of cases in the area.
Now, in a new study published in the journal mSystems, our scientists show that this method is able to rapidly detect novel variants of the virus and could provide an early warning sign of variants of concern becoming prevalent in the population.
The data revealed that the B.1.1.7 variant, also known as the Alpha variant or UK variant, was first identified in samples on 10 November 2020. It then rapidly increased in frequency to become the dominant variant, accounting for over 95 - 99% of cases by 26 January 2021. These findings closely matched data from clinical samples obtained over the same period.
Dr Javier Martin, who led the study, comments:
“Our work further highlights that environmental surveillance is a reliable way of monitoring coronavirus in the population and can be used to proactively identify new variants of concern.
“This method has an advantage over clinical surveillance as it can provide an immediate snapshot of how the virus is circulating between millions of individuals, including those with asymptomatic infections.
“In the future, environmental surveillance could also support vaccine strain selection based on prevalent variants if vaccines will need to be regularly updated as is currently the case for flu vaccines.”
The testing of wastewater samples at the NIBSC is ongoing and the most recent data reflects a shift in variants that have driving transmission over the last few months. The Alpha variant is now in decline, while other variants of concern are increasing in frequency. These findings are included in a latest report published by the Imperial College COVID-19 Response Team. Further information is available from the Imperial College website.