Air filter significantly reduces presence of airborne SARS-CoV-2 in COVID-19 wards

When a workforce of docs, scientists and engineers at Addenbrooke’s Hospital and the College of Cambridge positioned an air filtration machine in COVID-19 wards, they discovered that it eliminated virtually all traces of airborne SARS-CoV-2.

Whereas the invention might have implications for bettering the security of repurposed “surge wards,” the researchers say it additionally opens up the potential of having the ability to set requirements for cleaner air to scale back the chance of airborne transmission of infections.

Over the length of the pandemic there was a gentle rise within the proof that the SARS-CoV-2 virus may be transmitted by way of the air in small droplets (aerosols). However as hospitals have seen their capability overwhelmed, they’ve been pressured to handle a lot of their COVID-19 sufferers in repurposed ‘surge’ wards, which frequently lack the flexibility to vary the air with a excessive frequency. Whereas the usage of applicable private protecting gear (PPE) protects workers and sufferers considerably reduces the chance of transmission, there are nonetheless studies of patient-to-healthcare employee transmission of the virus, doubtlessly by way of the inhalation of viral particles.

A workforce on the College of Cambridge and Cambridge College Hospitals (CUH) NHS Basis Belief investigated whether or not transportable air filtration/UV sterilization units might cut back airborne SARS- CoV-2 on the whole wards that had been repurposed as a COVID ward and a COVID Intensive Care Unit (ICU). The outcomes are revealed in Medical Infectious Ailments.

Dr. Vilas Navapurkar, a Marketing consultant in Intensive Care Drugs at CUH, who led the research, mentioned: “Decreasing airborne transmission of the coronavirus is extraordinarily necessary for the security of each sufferers and workers. Efficient PPE has made an enormous distinction, however something we will do to scale back the chance additional is necessary.”

“Due to the numbers of sufferers being admitted with COVID-19, hospitals have had to make use of wards not designed for managing respiratory infections. Throughout an intensely busy time, we had been capable of pull collectively a workforce from throughout the hospital and College to check whether or not transportable air filtration units, that are comparatively cheap, may take away airborne SARS-CoV-2 and make these wards safer.”

The workforce carried out their research in two repurposed COVID-19 items in Addenbrooke’s Hospital. One space was a surge ward managing sufferers who required easy oxygen remedy or no respiratory assist; the second was a surge ICU managing sufferers who required air flow both by way of non-invasive masks air flow or invasive respiratory assist, resembling involving the usage of an invasive tube and tracheostomy.

The workforce put in a Excessive Effectivity Particulate Air (HEPA) air filter/UV sterilizer. HEPA filters are made up of 1000’s of fibers knitted collectively to kind a cloth that filters out particles above a sure measurement. The machines had been positioned in mounted positions and operated constantly for seven days, filtering the total quantity of air in every room between 5 and ten occasions per hour.

Within the surge ward, through the first week previous to the air filter being activated, the researchers had been capable of detect SARS-CoV-2 on all sampling days. As soon as the air filter was switched on and run constantly, the workforce had been unable to detect SARS-CoV-2 on any of the 5 testing days. They then switched off the machine and repeated the sampling—as soon as once more, they had been capable of detect SARS-CoV-2 on three of the 5 sampling days.

On the ICU, the workforce discovered restricted proof of airborne SARS-CoV-2 within the weeks when the machine was switched off and traces of the virus on one sampling day when the machine was lively.

Moreover, the air filters considerably diminished ranges of bacterial, fungal and different viral bioaerosols on the each the surge ward and the ICU, highlighting an added good thing about the system.

First writer Dr. Andrew Conway Morris, from the Division of Drugs on the College of Cambridge, mentioned: “We had been actually stunned by fairly how impact air filters had been at eradicating airborne SARS-CoV-2 on the wards. Though it was solely a small research, it highlights their potential to enhance the security of wards, notably in areas not designed for managing extremely infectious ailments resembling COVID-19.”

Crucially, the analysis workforce developed a sturdy method for assessing the standard of air, involving putting air samplers at varied factors within the room after which testing the samples utilizing PCR assays comparable these used within the ‘gold customary’ COVID-19 exams.

Professor Stephen Baker, from the Cambridge Institute of Therapeutic Immunology and Infectious Illness on the College of Cambridge, mentioned: “Cleaner air will cut back the chance of airborne illness transmission, but it surely’s unlikely to be the case that simply putting in an air filter can be sufficient to ensure the air is clear sufficient. Each room and each scenario can be totally different. A key a part of our work has been creating a sturdy means of measuring air high quality.”

Dr. Navapurkar added: “We’re all acquainted with the concept of getting requirements for clear water and of hygiene requirements for meals. We want now to agree requirements for what is appropriate air high quality and the way we meet and monitor these requirements.”