Tag Archive for: Infectious Disease Threats

Cambridge researchers honoured at Microbiology Society Annual Awards

Congratulations to Professors Sharon Peacock and Ravindra Gupta who received top awards at the Microbiology Society Annual Awards.

The Microbiology Society awards recognise excellence and are made to those making significant contributions in the field of microbiology, based on nominations received from its membership.

Winners are selected for their work to advance understanding of microbiology and champion the contribution made by microbiology and their work in addressing global challenges. 

Professor Sharon Peacock – Marjory Stephenson Prize 2023

Professor Sharon Peacock

Professor Sharon Peacock, Professor of Public Health and Microbiology at the University of Cambridge and researcher at NIHR Cambridge BRC, is an academic clinical microbiologist who has built her scientific expertise around pathogen genomics, antimicrobial resistance and a range of tropical diseases.

She was the founding director of COG-UK (the COVID-19 Genomics UK Consortium), formed in April 2020 to provide SARS-CoV-2 genomes to UK public health agencies, the National Health Service and researchers. Generating information on variants proved vital for their detection and tracking, and for studies of viral transmissibility, immune evasion, and disease severity.  

Professor Peacock has dedicated more than a decade of her career to the translation of pathogen sequencing into clinical and public health microbiology. She has also used sequencing to examine the extent to which antibiotic-resistant organisms can spread between humans, livestock and the environment. Over her career, Professor Peacock has raised more than £60M in science funding, published more than 500 peer-reviewed papers, and trained a generation of scientists in the UK and elsewhere.

She said of the award: “I am honoured to be the 2023 recipient of the Microbiology Society’s Marjory Stephenson Prize. The prize reflects the work of a large number of dedicated people in the COVID-19 Genomics UK Consortium and beyond, who worked voluntarily and tirelessly across the UK to generate SARS-CoV-2 genomes for public health agencies and researchers worldwide during the pandemic. 

“Microbiology has always been a vitally important discipline, but perhaps never more so than in this era of pandemics, antimicrobial resistance and the exploration of our microbiome and how this influences health and disease. I consider the scientific community fortunate in having the benefit of the ongoing contributions made by the Microbiology Society.” 

Professor Ravindra Gupta – Translational Microbiology Prize 2023

Ravindra-Gupta-Prof-Infectious-disease-threats-theme-lead

Professor Ravindra Gupta, Infectious Disease Threats theme lead at NIHR Cambridge BRC, has been a Professor of Clinical Microbiology at the Cambridge Institute for Therapeutic Immunology and Infectious Diseases since 2019.  

The Gupta lab based there has worked extensively in HIV drug resistance, both at molecular and population levels, and contributed to the appreciation of the scale of drug resistance globally. The group’s work extends to studies on HIV reservoirs in cells, particularly macrophages.

In 2020 Professor Gupta’s team validated and introduced the SAMBA II point of care test into clinical practice at Addenbrooke’s for rapid diagnosis of COVID-19. During the latter half of 2020 the lab started to study the evolution of the virus within patients in response to antibody-based therapies, as a paradigm of how new variants with multiple mutations have arisen.

The team is also characterising the virology of key spike protein mutations in new variants and their impact on natural and vaccine induced immunity. Professor Gupta is a co-opted member of the New and Emerging Respiratory Virus Threats Advisory Group (NERVTAG). NERVTAG advises the government on the threat posed by new and emerging respiratory viruses. 

In 2020 Professor Gupta was named as one of the 100 Most influential people by TIME. In 2021 he was elected to Fellowship of the Academy of Medical Sciences and in November 2022 featured in the Clarivate list of the world’s most highly cited scientists. 

He said of the award:  “I am thrilled and honoured to receive the Translational Microbiology Prize from the Microbiology Society. For me, it represents a recognition of the work of my team and our collaborators over the years in applying scientific knowledge to combat viruses such as HIV-1 and SARS-CoV-2. This award from an internationally reputed organisation in infectious diseases also provides impetus to continue our endeavours with ever greater passion and commitment.” 

A big congratulations also to Dr Tanmay Bharat, Programme Leader at the Medical Research Council (MRC) Laboratory of Molecular Biology (LMB) in Cambridge, who received the Fleming Prize 2023.

This article is adapted from Microbiology.org

Gone fishing: highly accurate test for common respiratory viruses uses DNA as ‘bait’

Research supported by NIHR Cambridge BRC has led to a new test that ‘fishes’ for multiple respiratory viruses at once using single strands of DNA as ‘bait’, giving highly accurate results in under an hour.

Cambridge researchers developed the test, which uses DNA ‘nanobait’ to detect the most common respiratory viruses – including influenza, rhinovirus, RSV and COVID-19 – at the same time.

In contrast, PCR (polymerase chain reaction) tests, while highly specific and highly accurate, can only test for a single virus at a time and take several hours to return a result.

While many common respiratory viruses have similar symptoms, they require different treatments. By testing for multiple viruses at once, the researchers say their test will ensure patients get the right treatment quickly and could also reduce the unwarranted use of antibiotics.

In addition, the tests can be used in any setting, and can be easily modified to detect different bacteria and viruses, including potential new variants of SARS-CoV-2, the virus which causes COVID-19. The results are reported in the journal Nature Nanotechnology.

The winter cold, flu and RSV season has arrived in the northern hemisphere, and healthcare workers must make quick decisions about treatment when patients show up in their hospital or clinic.

Similar symptoms, different treatments

“Many respiratory viruses have similar symptoms but require different treatments: we wanted to see if we could search for multiple viruses in parallel,” said Filip Bošković from Cambridge’s Cavendish Laboratory, the paper’s first author. “According to the World Health Organization, respiratory viruses are the cause of death for 20% of children who die under the age of five. If you could come up with a test that could detect multiple viruses quickly and accurately, it could make a huge difference.”

For Bošković, the research is also personal: as a young child, he was in hospital for almost a month with a high fever. Doctors could not figure out the cause of his illness until a PCR machine became available.

“Good diagnostics are the key to good treatments,” said Bošković, who is a PhD student at St John’s College, Cambridge. “People show up at hospital in need of treatment and they might be carrying multiple different viruses, but unless you can discriminate between different viruses, there is a risk patients could receive incorrect treatment.”

PCR tests are powerful, sensitive and accurate, but they require a piece of genome to be copied millions of times, which takes several hours.

The Cambridge researchers wanted to develop a test that uses RNA to detect viruses directly, without the need to copy the genome, but with high enough sensitivity to be useful in a healthcare setting.

“For patients, we know that rapid diagnosis improves their outcome, so being able to detect the infectious agent quickly could save their life,” said co-author Professor Stephen Baker, from the Cambridge Institute of Therapeutic Immunology and Infectious Disease. “For healthcare workers, such a test could be used anywhere, in the UK or in any low- or middle-income setting, which helps ensure patients get the correct treatment quickly and reduce the use of unwarranted antibiotics.”

The researchers based their test on structures built from double strands of DNA with overhanging single strands. These single strands are the ‘bait’: they are programmed to ‘fish’ for specific regions in the RNA of target viruses. The nanobaits are then passed through very tiny holes called nanopores. Nanopore sensing is like a ticker tape reader that transforms molecular structures into digital information in milliseconds. The structure of each nanobait reveals the target virus or its variant.

The researchers showed that the test can easily be reprogrammed to discriminate between viral variants, including variants of the virus that causes COVID-19. The approach enables near 100% specificity due to the precision of the programmable nanobait structures.

“This work elegantly uses new technology to solve multiple current limitations in one go,” said Baker. “One of the things we struggle with most is the rapid and accurate identification of the organisms causing the infection. This technology is a potential game changer; a rapid, low-cost diagnostic platform that is simple and can be used anywhere on any sample.”

A patent on the technology has been filed by Cambridge Enterprise, the University’s commercialisation arm, and co-author Professor Ulrich Keyser has co-founded a company, Cambridge Nucleomics, focused on RNA detection with single-molecule precision.

“Nanobait is based on DNA nanotechnology and will allow for many more exciting applications in the future,” said Keyser, who is based at the Cavendish Laboratory. “For commercial applications and roll-out to the public we will have to convert our nanopore platform into a hand-held device.”

“Bringing together researchers from medicine, physics, engineering and chemistry helped us come up with a truly meaningful solution to a difficult problem,” said Bošković, who received a 2022 PhD award from Cambridge Society for Applied Research for this work.

Blood thinning drug to treat recovery from severe Covid is not effective

A UK-wide trial, led by Addenbrooke’s Hospital and the University of Cambridge, has found that a drug used to reduce the risk of blood clots does not help patients recovering from moderate and severe Covid – despite this approach being offered to patients.

The HEAL-COVID trial (Helping to Alleviate the Longer-term consequences of Covid-19) is funded by the NIHR and the NIHR Cambridge Biomedical Research Centre. To date, more than a thousand NHS patients hospitalised with Covid have taken part in HEAL-COVID, a platform trial that is aiming to find treatments to reduce the number who die or are readmitted following their time in hospital.

In these first results from HEAL-COVID, it’s been shown that prescribing the oral anticoagulant Apixaban does not stop Covid patients from later dying or being readmitted to hospital over the following year (Apixaban 29.1%, versus standard care 30.8%).

As well as not being beneficial, anticoagulant therapy has known serious side effects, and these were experienced by participants in the trial with a small number of the 402 participants receiving Apixaban having major bleeding that required them to discontinue the treatment.

There was also no benefit from Apixaban in terms of the number of days alive and out of hospital at day 60 after randomisation (Apixaban 59 days, versus standard care 59 days).

Following these results, the trial will continue to test another drug called Atorvastatin, a widely used lipid lowering drug (‘a statin’) that acts on other mechanisms of disease that are thought to be important in Covid.

Professor Charlotte Summers

Chief Investigator for the trial Professor Charlotte Summers, is an intensive care specialist at Addenbrooke’s Hospital and the University of Cambridge, pictured right, said: “Having survived the ordeal of being hospitalised with Covid-19, far too many patients find themselves back in hospital, often developing longer-term complications as a result of the virus. There is an urgent need for us to find treatments that prevent this significant burden of illness and improve the lives of so many still being affected by Covid.”

“These first findings from HEAL-COVID show us that a blood thinning drug, commonly thought to be a useful intervention in the post-hospital phase is actually ineffective at stopping people dying or being readmitted to hospital.  This finding is important because it will prevent unnecessary harm occurring to people for no benefit.   It also means we must continue our search for therapies that improve longer term recovery for this devastating disease.”

Dr-Mark-Toshner

Dr Mark Toshner, joint Chief Investigator for HEAL-COVID, pictured left, said: “Up until now it’s been assumed that Apixaban helps patients recover after severe Covid-19 and that thinning their blood to prevent clots is beneficial.  This trial is the first robust evidence that longer anticoagulation after acute Covid-19 puts patients at risk for no clear benefit.

“Our hope is that these results will stop this drug being needlessly prescribed to patients with Covid-19 and we can change medical practise.  Finding out that a treatment doesn’t work is really important.  It’s not the solution many hoped it would be, with our results highlighting once again why testing treatments in randomised trials is important.”

“At present, the world’s research efforts have focussed on acute Covid-19. We now urgently need evidence about how to best treat patients beyond their initial infection.”

Professor Nick Lemoine, NIHR Clinical Research Network Medical Director, said: “Research into Covid-19 recovery remains vital as we move out of the pandemic. Results such as these from the HEAL-COVID study, help to strengthen our knowledge of how patients can be treated following their stay in hospital and how recovery rates can be improved upon.

“Findings from clinical trials, whether they identify new treatments or rule out methods of care, are vital and rigorous evidence when it comes to changing best medical practice.”

The trial is being led by Cambridge University Hospitals NHS Foundation Trust (CUH) and University of Cambridge, in collaboration with Liverpool Clinical Trials Centre (University of Liverpool) and Aparito Limited. 

HEAL-COVID enrols patients when they are discharged from hospital, following their first admission for Covid-19.  They are randomised to a treatment and their progress tracked.

Cambridge researchers listed among world’s most influential researchers

Congratulations to our NIHR Cambridge BRC theme leads who have been named in the Clarivate listings of the ‘world’s most influential researchers’.

The researchers were selected on their exceptional research influence and highly cited research papers that rank in the top 1% by citations on the global database, Web of Science, over the last decade.  

The full list of Cambridge researchers can be found on the Clarivate website.

NameTitleAssociated theme
Professor Ed BullmoreHonorary Consultant Psychiatrist and Head of the Department of PsychiatryMental Health
Professor John DaneshProfessor of EpidemiologyPopulation and quantitative sciences
Professor Ravindra K. GuptaProfessor of Clinical MicrobiologyAntimicrobial resistance
Professor David Rowitch Developmental neuroscientist and Head of Department of Paediatrics Women’s health and paediatrics

High blood pressure is directly linked to severe COVID-19

A study led by Addenbrooke’s Hospital and the University of Cambridge has shown that people with high blood pressure are more likely to be admitted to hospital or die from COVID-19, regardless of other factors such as age, sex, ethnicity or BMI.

The research, published this week in the Journal PLOS ONE, is the first study to show the extent to which high blood pressure, known as hypertension, can be directly linked to patients developing severe COVID-19. 

It also showed that the type of medication people were receiving to treat hypertension did not appear to modify this risk.  In addition, those patients who had poorly controlled blood pressure i.e. above treatment targets, were at the highest risk of dying or being hospitalised.

The study findings may help explain why ethnic minority and low-income groups were disproportionately affected by COVID-19, as hypertension is more common in these individuals, and rates of blood pressure control poorer (see notes).

The research has important implications for public health priorities, given that hypertension is already the leading risk factor for death in the UK. 

It also comes as rates of blood pressure control have worsened in the UK, due to the pandemic, with the number or people being screened and identified with the condition dropping as well (see notes).

Holly Pavey is lead author of the study and a British Heart Foundation (BHF) funded PhD student at the University of Cambridge.  She said:

“Before this research, it wasn’t clear to what extent high blood pressure was putting patients at greater risk of hospitalisation or dying from COVID-19.  Other factors such as age, socio-economic status, sex, ethnicity and BMI were all in the frame too as increasing the risk of severe COVID-19.  

“By using data from many thousands of UK volunteers, we found that in individuals who tested positive for COVID-19, those with high blood pressure had a 22% higher risk of being hospitalised of dying from the virus, compared to those without high blood pressure.   This risk was almost doubled for those with poorly controlled blood pressure.”

The research was supported by the NIHR Cambridge Biomedical Research Centre and use data from the UK Biobank, a research database, containing in-depth genetic and health information from half a million UK volunteers. The study included over 16,000 of these individuals who had tested positive for COVID-19 and who had linked GP records, death records and COVID-19 lab results. 

Researchers analysed data up until early 2021, which helped to reduce any bias from new variants of the virus, which were much more transmissible, as well as reducing any bias from the effects of widespread vaccinations.

However, the UK Biobank volunteer population is generally healthier than the general UK population and has relatively few participants from ethnic minority groups, so generalisations to the wider UK population need to be undertaken with caution.

Even though the death and hospitalisation rate due to COVID-19 has been hugely reduced over the last year due to virus mutations, the NHS vaccination program and availability of effective treatments, this research highlights the importance of having well-controlled blood pressure, in case of new, more severe strains of COVID-19 or other viruses in the future.

Ian Wilkinson, a cardiology consultant at Cambridge University Hospitals NHS Foundation Trust (CUH) and Professor of Therapeutics at the University of Cambridge, is the study’s senior author.  He said: “Hypertension remains the leading risk factor for death in the UK and worldwide, despite effective treatments, and disproportionately affects low income groups and individuals from ethnic minority backgrounds.

“Our findings further emphasise the importance of adequate blood pressure control. Unfortunately, post-pandemic, the rates of blood pressure control have worsened, as have the number of people being screened and identified as having high blood pressure. This is now a major public health problem in the UK and needs to be addressed as part of the levelling-up agenda”.

A national trial is currently underway to improve treatments for hypertension, specifically for people from black, Asian and minority ethnic communities.  At the moment most treatments have been tested mainly on white people and it’s not known if these are as effective on other ethnic groups.  

The AIM HY trial is led by Professor Ian Wilkinson and Phil Chowienczyk, Professor of Clinical Cardiovascular Pharmacology, Kings College London and Chief Investigator for the trial. 

Professor Chowienczyk said: “These findings highlight the importance of good blood pressure control, especially in individuals disproportionately affected by high blood pressure and COVID-19, such as those in ethnic minority groups in the UK. The AIM HY_INFORM trial is a major study, funded by the BHF and Medical Research Council, that will determine which drugs are most effective at lowering blood pressure in ethnic minority groups in the UK. This should report at the end of 2023 and will be instrumental in shaping new guidelines for the treatment of hypertension in the UK.”

Referrals to long COVID clinic fell by 79% following roll-out of the vaccine

Referrals to Cambridge’s long COVID clinic fell dramatically in the period August 2021 to June 2022, which researchers say is likely due to the successful rollout of the vaccine.

According to the Office of National Statistics, in July this year an estimated 2 million people in the UK were living with self-reported long COVID – that is, symptoms continuing for more than four weeks after their first suspected coronavirus (COVID-19) infection. Patients report symptoms including fatigue, muscle aches, memory problems and shortness of breath more than six months post-acute COVID-19, and a significant number of patients have not fully recovered two years since the initial infection.

Two recent studies have suggested that vaccination strongly reduced long COVID symptoms one-to-three months after infection, but another study using a cohort of US Army Veterans suggested a more modest, 15% reduction at six months.

In May 2020, Addenbrooke’s Hospital, part of Cambridge University Hospitals NHS Foundation Trust (CUH), set up a long COVID clinic, with patients referred to the clinic based on a number of criteria, one of which is symptoms duration of at least five months. These patients tend to be those on the severe end of the symptom spectrum, having been referred following assessment by a team that includes a GP, mental health practitioners, physio and occupational therapists amongst other specialists.

Researchers at the Cambridge Institute of Therapeutic Immunology & Infectious Disease (CITIID) at the University of Cambridge and CUH, analysed data from the clinic and found a 79% drop in the number of patients being referred to the clinic from August 2021 to June 2022, compared to August 2020 to July 2021. The decrease began five months after people started receiving second doses of COVID-19 vaccines.

Six-month moving averages fell from around 10 referrals per month to just one or two referrals per month. This effect has so far been sustained until at least June 2022, despite four times more cases per month of acute COVID-19 in England across the same time periods.

Dr Ben Krishna from the University of Cambridge said: “Long COVID can have a significant impact on an individual’s life, and the large number of patients still experiencing symptoms many months after infection is placing additional strain on our healthcare services.

“We know that rollout of the vaccines has had a major impact on the number and severity of COVID infections, and evidence from our clinic suggests that it has also played an important role in reducing the rates of the most severe long COVID cases.”

The researchers say that it is possible – but unlikely – that the emergence of the Delta variant may also have affected long COVID rates. However, the observed reduction in long COVID rates in August 2021 was from patients experiencing symptoms for five months, which they say would suggest a change beginning in March 2021. This correlates well with the second doses of vaccination in the UK, but the Delta wave did not begin until April 2021.

The team say they also cannot rule out prior infections providing immunity that protects against long COVID from reinfections; however, primary infections were more common than reinfections around March-April 2021.

The team observed no changes in symptoms between those referred for long COVID before or after vaccination for any of the major symptoms such as fatigue (73% pre-vaccination vs 76% post vaccination) and shortness of breath (18% pre-vaccination vs 23% post-vaccination).

It is not yet clear what level of immunity is required to protect against long COVID, say the researchers. As immunity wanes over time, booster shots – including variant-specific booster shots – may be necessary to minimise long COVID risk.

Dr Nyaradzai Sithole from CUH said: “As the virus continues to circulate and infect – and in many cases, re-infect – people, it’s important that everyone is up-to-date with their vaccinations. This will not only help prevent, or at least lessen, their primary COVID infection, but should reduce their risk of long COVID. But whether with the emergence of new variants we will begin to see an uptick in the number of cases of long COVID remains to be seen.”

The study is published in Clinical Infectious Diseases.

The research as funded by the Addenbrooke’s Charitable Trust and the National Institute for Health and Care Research (NIHR), with support from the NIHR Cambridge Biomedical Research Centre.

Paper Reference
Krishna, B et al. Reduced incidence of Long COVID referrals to the Cambridge University Teaching Hospital Long COVID clinic. Clinical Infectious Diseases; 1 Aug 2022; DOI: 10.1093/cid/ciac630


Cambridge researchers awarded Fellow status

Congratulations to our NIHR Cambridge BRC researchers who have been elected as Fellows of the Academy of Medical Sciences.

In 2022, 60 Fellows have been elected for their contributions to biomedical and health science, the highest number elected into the academy in a single year.

The Academy of Medical Sciences aims to advance biomedical and health research and its translation into benefits to society. Fellows are selected from laboratory science, clinical academic medicine, veterinary science, dentistry, medical and nursing care, and other professions allied to medical science including ethics, social science and law.

Prof Miles Parkes

Professor Miles Parkes, director of the NIHR Cambridge BRC and one of our newly elected Fellows said: “I feel very honoured to have been elected as a fellow of the Academy of Medical Sciences and am very grateful both to the colleagues who nominated and supported my application and the many patients and collaborators across who have played a critical role in the success of our IBD research.”

Professor Fiona Gilbert - Imaging theme lead

Professor Fiona Gilbert, Imaging Lead at NIHR Cambridge BRC and newly awarded Fellow said: “Our work here on the Cambridge biomedical campus brings together clinical teams, research and patients, enabling pioneering working in so many fields of medicine and life science.”

Cambridge researchers elected as Fellows

Professor Miles Parkes, Consultant Gastroenterologist and Director, Addenbrooke’s Hospital NIHR Cambridge BRC director

Professor Fiona Gilbert, Head of the Department of Radiology, University of Cambridge and NIHR Cambridge BRC Imaging Theme Lead

Professor Sarah-Jayne Blakemore, Professor of Psychology and Cognitive Neuroscience, University of Cambridge, NIHR Cambridge BRC researcher

Professor David Savage, Professor of Molecular Metabolism, University of Cambridge NIHR Cambridge BRC researcher

Professor Rodrigo Floto, Professor of Respiratory Biology, University of Cambridge

Dr John Marioni, Senior Group Leader, University of Cambridge

Professor Susan Ozanne, Professor of Developmental Endocrinology, University of Cambridge

Professor Anna Philpott, Head of the School of Biological Sciences, University of Cambridge

Using air filters on hospital wards remove almost all airborne Covid virus

A new study has found placing air filtration machines in COVID-19 wards at Addenbrooke’s Hospital, removed almost all traces of airborne SARS-CoV-2 virus.

Supported by the NIHR Cambridge BRC, the research was led by doctors, scientists and engineers at Addenbrooke’s and the University of Cambridge in January, at the height of the second wave of the pandemic.

This discovery could have implications for improving the safety of repurposed ‘surge wards’, the researchers say it also opens up the possibility of being able to set standards for cleaner air to reduce the risk of airborne transmission of infections.

Over the duration of the pandemic there has been a steady rise in the evidence that the SARS-CoV-2 virus can be transmitted through the air in small droplets (aerosols). But as hospitals have seen their capacity overwhelmed, they have been forced to manage many of their COVID-19 patients in repurposed ‘surge’ wards, which often lack the ability to change the air with a high frequency. While the use of appropriate personal protective equipment (PPE) protects staff and patients significantly reduces the risk of transmission, there are still reports of patient-to-healthcare worker transmission of the virus, potentially through the inhalation of viral particles.

A team at the University of Cambridge and Cambridge University Hospitals (CUH) NHS Foundation Trust investigated whether portable air filtration/UV sterilisation devices could reduce airborne SARS- CoV-2 in general wards that had been repurposed as a COVID ward and a COVID Intensive Care Unit (ICU). The results are published in Clinical Infectious Diseases.

An airfilter machine and Dr Vilas Navapurkar, who led the study

Dr Vilas Navapurkar, a Consultant in Intensive Care Medicine at CUH, who led the study, said: “Reducing airborne transmission of the coronavirus is extremely important for the safety of both patients and staff. Effective PPE has made a huge difference, but anything we can do to reduce the risk further is important.”

“Because of the numbers of patients being admitted with COVID-19, hospitals have had to use wards not designed for managing respiratory infections. During an intensely busy time, we were able to pull together a team from across the hospital and University to test whether portable air filtration devices, which are relatively inexpensive, might remove airborne SARS-CoV-2 and make these wards safer.”

The team performed their study in two repurposed COVID-19 units in Addenbrooke’s Hospital. One area was a surge ward managing patients who required simple oxygen treatment or no respiratory support; the second was a surge ICU managing patients who required ventilation either through non-invasive mask ventilation or invasive respiratory support, such as involving the use of an invasive tube and tracheostomy.

The team installed a High Efficiency Particulate Air (HEPA) air filter/UV steriliser. HEPA filters are made up of thousands of fibres knitted together to form a material that filters out particles above a certain size. The machines were placed in fixed positions and operated continuously for seven days, filtering the full volume of air in each room between five and ten times per hour.

In the surge ward, during the first week prior to the air filter being activated, the researchers were able to detect SARS-CoV-2 on all sampling days. Once the air filter was switched on and run continuously, the team were unable to detect SARS-CoV-2 on any of the five testing days. They then switched off the machine and repeated the sampling – once again, they were able to detect SARS-CoV-2 on three of the five sampling days.

On the ICU, the team found limited evidence of airborne SARS-CoV-2 in the weeks when the machine was switched off and traces of the virus on one sampling day when the machine was active.

Additionally, the air filters significantly reduced levels of bacterial, fungal and other viral bioaerosols on the both the surge ward and the ICU, highlighting an added benefit of the system. 

First author Dr Andrew Conway Morris, from the Department of Medicine at the University of Cambridge, said: “We were really surprised by quite how effect air filters were at removing airborne SARS-CoV-2 on the wards. Although it was only a small study, it highlights their potential to improve the safety of wards, particularly in areas not designed for managing highly infectious diseases such as COVID-19.”

Crucially, the research team developed a robust technique for assessing the quality of air, involving placing air samplers at various points in the room and then testing the samples using PCR assays similar those used in the ‘gold standard’ COVID-19 tests.

Professor Stephen Baker, from the Cambridge Institute of Therapeutic Immunology and Infectious Disease at the University of Cambridge, said: “Cleaner air will reduce the risk of airborne disease transmission, but it’s unlikely to be the case that just installing an air filter will be enough to guarantee the air is clean enough. Every room and every situation will be different. A key part of our work has been developing a robust way of measuring air quality.”

Dr Navapurkar added: “We’re all familiar with the idea of having standards for clean water and of hygiene standards for food. We need now to agree standards for what is acceptable air quality and how we meet and monitor those standards.”

The research was also supported by Wellcome and the Medical Research Council.

Adapted from University of Cambridge release

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