COVID-19: Beyond the clinical space
As the rollout of vaccinations begins to gain momentum around the world, there exists a tentative hope that the ‘beginning of the end’ of the COVID-19 pandemic may be starting to take shape, at least in terms of the outbreak’s most ferocious epoch. But whilst vaccinations may deal a substantial blow to the virus, they do not signify its demise. Moving forward, it will be increasingly important to monitor the levels of SARS-CoV-2 virus beyond the confines of individual cases.
Waste water
A study published in May 2020 by Wurtzer et al. observed a clear correlation between the quantity of SARS-CoV-2 genomes in Parisian wastewater and the number of new COVID-19 cases observed at a regional level. Indeed, the association was significant enough that, when COVID-19 cases dropped in the population, researchers observed a subsequent marked decrease in SARS-CoV-2 genomes in wastewater. Of particular note is the fact that SARS-CoV-2 genomes could be detected in waste water before the beginning of the exponential growth of the epidemic.
Needless to say, there are significant implications to such an observation. As the SARS-CoV-2 virus begins its slow transition from pan- to endemic, the possibility of being able to forecast regional outbreaks in advance represents a powerful tool for government officials, researchers, and medical professionals. As Larsen and Wigginton note in their September 2020 Nature Biotechnology paper, wastewater surveillance is “a cost-effective way to survey transmission dynamics of entire communities,” one which avoids the biases of other epidemiological indicators and which collects data from an entire population, including those are, for one reason or another, otherwise unreachable by the healthcare system. “If it were successful in revealing infection dynamics earlier than diagnostic testing, it could provide public-health officials with near-real-time information on disease prevalence.”
Viral wastewater testing is, in fact, nothing new. The Wurzer et al. study follows in the footsteps of other studies and programmes that have successfully used urban wastewater to monitor phenomena as disparate as polio outbreaks and ecstasy use. One piece of research from 2015 – also focusing on Paris – concluded that there exists a ‘significant underestimation’ of the diversity of enteric viruses circulating in the human population. Consequently, the analysis of wastewater treatment plant effluents could “allow the exploration of viral diversity not only in environmental waters but also in a human population linked to a sewerage network in order to better comprehend viral epidemiology and to forecast seasonal outbreaks.”
AXIO Proficiency Testing As we move into the post-pandemic era, it is essential that laboratories monitoring SARS-CoV-2 levels in waste water ensure their methods and results are reliable and accurate. For this reason, LGC AXIO Proficiency Testing is proud to be announcing the launch of a new proficiency testing scheme for the detection and quantification of SARS-CoV-2 in wastewater by nucleic acid amplification testing.
Participants in the scheme, which launches in March 2021, will be sent non-infectious samples provided in a synthetic wastewater matrix. These samples are compatible with molecular assays that target CDC and WHO consensus gene sequence regions ORF1a, RdRp, E (Envelope), N (Nucleocapsid) and/or S (Spike). "Governments, health bodies, hospitals, virology labs and indeed most of the world’s population find themselves locked in a war with the novel virus COVID-19,” says Brian Brookman, Chief Scientific Officer, LGC AXIO. “LGC is directly involved in COVID-19 related work, from supporting diagnostic kit manufacturers, diagnostic testing and clinical research to providing quality assurance tools to ensure reliability of measurements being made. “It is our hope that by using this new wastewater proficiency testing program for SARS-CoV-2, external quality assurance measures will be in place to support all such testing worldwide. Together we can ensure accurate and reliable testing as the world unites to combat the spread of the virus.”
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Fomites
Early on in the pandemic, studies confirming the ability of the SARS-CoV-2 virus to survive on surfaces for days on end were widely circulated by the media. The alarm was not without merit – one study, which employed a DNA oligonucleotide surrogate for contaminated bodily fluid, showed that, in a 10 hour period, viral DNA left on a hospital bed rail in an isolation room had spread to 18 other surfaces, including door handles, waiting room chairs, and children’s toys and books in a play area.
Since then, our understanding of SARS-CoV-2 has developed. Hand disinfection has been shown to substantially reduce relative risks of transmission independently of the disease’s prevalence on a surface and the frequency of contact, even with low or moderate compliance, and fomite spread is no longer thought to be a significant means of transmission in real-world operational scenarios.
Needless to say, a laboratory is far from a typical ‘real world’ environment, particularly (though not exclusively) one in which SARS-CoV-2 samples are handled regularly. The risk of a laboratory shutdown based on the surface detection of SARS-CoV-2 genomes remains high, and precautionary measures including regular cleaning and disinfection should be taken by all laboratories, in order both to protect staff and to avoid disrupting vital scientific work at what is, for many territories, a critical moment in the pandemic.
It is therefore essential that laboratories ensure that their methods and results are reliable. LGC AXIO’s Surface Testing for SARS-CoV-2 proficiency testing scheme launched last June to provide laboratories with the feedback necessary to ensure the accuracy of their procedures, and the scheme is continuing through 2021. Participants will receive two 1.5ml liquid samples – via a swab test, the detection of a non-infectious SARS-CoV-2 simulant will be assessed.
Since the emergence of SARS-CoV-2, over a year ago now, the global scientific community has pulled together in an unprecedented manner to gain insight into the behaviour of the virus and guide legislators towards a suitable response. At this critical historical moment, as vaccination programmes offer the possibility of quelling the pandemic’s initial fury, we cannot afford to take our feet ‘off the gas’.
LGC AXIO Proficiency Testing is on-hand to ensure that your laboratory is maintaining the highest possible standards when it comes to SARS-CoV-2 detection beyond the clinical space. We look forward to working with you.