Wastewater-based monitoring of SARS-CoV-2 at UK airports and its potential role in international public health surveillance

Kata Farkas; Rachel Williams; Natasha Alex-Sanders; Jasmine M S Grimsley; Igor Pântea; Matthew J Wade; Nick Woodhall; Davey L Jones

doi:10.1371/journal.pgph.0001346

Wastewater-based monitoring of SARS-CoV-2 at UK airports and its potential role in international public health surveillance

PLOS Glob Public Health. 2023 Jan 19;3(1):e0001346. doi: 10.1371/journal.pgph.0001346. eCollection 2023.

Authors

Kata Farkas^{1

2}, Rachel Williams¹, Natasha Alex-Sanders¹, Jasmine M S Grimsley^{3

4}, Igor Pântea¹, Matthew J Wade^{3

5}, Nick Woodhall¹, Davey L Jones^{1

6}

Affiliations

¹ Centre for Environmental Biotechnology, School of Natural Sciences, Bangor University, Bangor, Gwynedd, United Kingdom.
² School of Ocean Sciences, Bangor University, Menai Bridge, Anglesey, United Kingdom.
³ Data, Analytics, and Surveillance Group, UK Health Security Agency, London, United Kingdom.
⁴ The London Data Company, London, United Kingdom.
⁵ School of Engineering, Newcastle University, Newcastle-upon-Tyne, United Kingdom.
⁶ Food Futures Institute, Murdoch University, Murdoch, Australia.

Abstract

It is well established that air travel plays a key role in the global spread of many enteric and respiratory diseases, including COVID-19. Even with travel restrictions (e.g. mask wearing, negative COVID-19 test prior to departure), SARS-CoV-2 may be transmitted by asymptomatic or pre-symptomatic individuals carrying the virus. Due to the limitation of current clinical surveillance approaches, complementary methods need to be developed to allow estimation of the frequency of SARS-CoV-2 entry across international borders. Wastewater-based epidemiology (WBE) represents one such approach, allowing the unbiased sampling of SARS-CoV-2 carriage by passenger cohorts entering via airports. In this study, we monitored sewage in samples from terminals (n = 150) and aircraft (n = 32) at three major international airports in the UK for 1-3 weeks in March 2022. As the raw samples were more turbid than typical municipal wastewater, we used beef extract treatment followed by polyethylene glycol (PEG) precipitation to concentrate viruses, followed by reverse transcription quantitative PCR (RT-qPCR) for the detection of SARS-CoV-2 and a faecal indicator virus, crAssphage. All samples taken from sewers at the arrival terminals of Heathrow and Bristol airports, and 85% of samples taken from sites at Edinburgh airport, were positive for SARS-CoV-2. This suggests a high COVID-19 prevalence among passengers and/or airport staff members. Samples derived from aircraft also showed 93% SARS-CoV-2 positivity. No difference in viral prevalence was found before and after COVID-19 travel restrictions were lifted. Our results suggest that WBE is a useful tool for monitoring the global transfer rate of human pathogens and other disease-causing agents across international borders and should form part of wider international efforts to monitor and contain the spread of future disease outbreaks.

Copyright: © 2023 Farkas et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Grants and funding

KF, RW, NAS, JMSG, MJW, DLJ: The work was supported by the Environmental Monitoring for Health Protection Programme using funds provided by the UK Department of Health and Social Care. The funder was involved in sampling design and organised sampling through external partners. DLJ: The Centre for Environmental Biotechnology Project was funded though the European Regional Development Fund (ERDF) by Welsh Government. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.