Dr Isobel Stanton is a Molecular Biologist at the UK Centre for Ecology and Hydrology working on wastewater-based epidemiology of Covid-19 at an institutional level and the environmental dimension of antimicrobial resistance. Prior to this, she undertook her PhD and a postdoctoral research position at the University of Exeter Medical School, also investigating the environmental dimension of antimicrobial resistance.
The COVID-19 pandemic is one of the biggest global health crises of this century. SARS-CoV-2, the causative agent of COVID-19, was initially identified in China in 2019 but has since spread around the world to all continents. To date, there have been over 194 million cases and over 4 million deaths globally since the virus was first identified. rnWastewater based epidemiology is a surveillance tool used to monitor the health of the population. Previously this has included measuring infectious diseases, tracking antimicrobial resistance and monitoring both the use of prescription drugs and illicit drugs excreted at a population level. In the past two years WBE has become an important tool in the monitoring of the spread of SARS-CoV-2 in a number of countries around the world. Surveillance strategies range from whole populations in a particular geographical region by monitoring SARS-CoV-2 levels in municipal wastewater treatment plants to targeting more specific populations, such as the monitoring of University accommodation at the University of Arizona. rnThe aim of the TERM project has been to undertake near-source WBE for SARS-CoV-2 in a number of specific populations in the United Kingdom. We have been monitoring levels of SARS-CoV-2 in the wastewater from primary and secondary schools October 2020 July 2021 and prison populations February 2021 June 2021 in the UK. By using near-source tracking of these enclosed populations it is possible to obtain from these institutions information about population demographics, infections and whether the resultant disease was symptomatic or asymptomatic. rnWe used reverse transcriptase quantitative PCR to target both the N1 nucleocapsid and E envelope genes of SARS-CoV-2. rnIn school wastewater we found:rn1.N1 ranged from undetectable to 9.20x106 copies per litre with a mean copy number of 9.03x104 for all school sites over the sampling period.rn2.E ranged from undetectable to 1.13x106 copies per litre with a mean copy number of 4.72x104 for all school sites over the sampling period.rnIn prison wastewater we found:rn1.N1 ranged from undetectable to 1.9x108 copies per litre with a mean copy number of 1.41x106 for all prison sites over the sampling period. rn2.E ranged from undetectable to 1.18x108 copies per litre with a mean copy number of 1.38x106 for all prison sites over the sampling period.rnDuring our study periods we have tracked and followed the full epidemic outbreak curve at one of the prison sampling sites. We have also identified cases from wastewater in school samples where no symptomatic case had been identified by the school. Based on our data we have been able to inform both institutions and local health authorities on whether mass surge testing of the various populations was needed to identify cases.rnWhilst community testing has been important in helping to curb the spread of SARS-CoV-2, wastewater based epidemiology methods can also play a complementary role by characterising the disease burden in the total population. This is particularly important in enclosed populations such as schools and prisons where transmission of this virus has been shown to be high.