Infection Control guidance and airborne transmission

Guidelines are fundamentally flawed and putting health care workers and patients at serious risk

  • UK infection control guidelines are not fit for purpose.  IPC authorities are increasingly isolated in their view that Covid-19 is spread by droplets and not through the air, a position which is directly contradicted now by official government policy.  What follows is a more detailed look at the issues, which demonstrates how unscientific, out of touch and indeed hazardous the guidelines are for health workers and patients.
  • There is widespread consensus that the guidelines are fundamentally flawed and not fit for purpose.  Many expert scientists and health professionals have spoken out publicly about them, and repeatedly asked for them to be changed.  The Royal College of Nurses calls the guidance  “fundamentally flawed”, while the British Medical Association wrote to the prime minister in February 2021 along with 16 health organisations, stating the guidance needs revision as it fails to take into account airborne spread or recommend airborne mitigations.  To date 26 different health organisations have called for airborne protections for staff, to no avail.
  • IPC is isolated in its view that airborne transmission does not occur.  The Department for Education is putting in place airborne mitigations (CO2 monitors and air filtration units) in schools and the Department of Health and Social Care has just embarked on a major health education drive for the public to improve ventilation in their homes over the festive period to limit airborne transmission.  Newly updated guidance from the government says airborne transmission is a very significant way that the virus circulates.  The idea that airborne transmission occurs everywhere else, but stops at the hospital front door is ludicrous.
  • IPC’s belief that airborne spread is only a risk from certain aerosol generating procedures (AGPs) has now been thoroughly discredited by numerous clinical studies.  Not only do so-called AGPs not constitute additional risk, a patient with Covid who is actively coughing produces far more aerosols.  Experts are now openly calling for us to stop using the term AGP altogether. This review article in the Lancet states:

“We propose an end to the term aerosol generating procedure, as it is neither accurate (aerosol is not generated above a cough for many of these procedures), implies aerosol emission is only from specific procedures (rather than being generated during normal respiratory events), potentially misidentifies the source of infection risk, and applies a binary definition to a situation that is more complex. Instead, we propose that clinicians follow an evidence-based framework that accounts for the major drivers of risk, with a focus on physical exposure to patients with suspected or confirmed COVID-19 as the critical component.”

  • There is widespread dismay and frustration by health trade unions, numerous health organisations and large sections of the medical and scientific community at the refusal of IPC to amend the guidance.  Concerted efforts for well over a year to get IPC to change have proved futile, despite overwhelming evidence of airborne transmission, and the multiple criticisms of the failings of the guidelines from clinicians and scientists.
  • In practice IPC’s policies have failed comprehensively to protect health and social care workers – more than 1,500 of whom have died from Covid, according to former Health Secretary Matt Hancock, and over 120,000 health workers and 30,000 social care workers have long Covid according to the ONS. These figures predate the onset of delta Covid, which is more infectious and can lead to more serious disease; the figures now are therefore likely to be higher, despite most HCWs now being vaccinated.
  • There has also been wholesale failure to keep patients in hospital safe from Covid infection.  Tens of thousands of patients have been infected while they were in hospital for other health conditions.  During the terrible second wave last winter, an average of 20% of Covid infections were hospital acquired; this dropped substantially over the summer, but the rate is now over 8% and rising.
  • Over 11,600 patients have died from hospital acquired Covid-19 infection,  according to a recent article in the Daily Telegraph.  This is an indictment of infection control in our hospitals and a national scandal.  
  • An NHS spokesperson said in response to the Telegraph article that staff had “rigorously followed UK Health Security Agency (formerly PHE) infection prevention control guidance”.  No doubt this is true, therefore the inescapable conclusion is that it is the guidance which is comprehensively failing to protect staff and patients.  Until we have guidance which accepts the predominance of airborne transmission, and that this is a risk everywhere in our hospitals, thousands more patients will get infected with Covid in hospital and many will die.  Health workers will also continue to get infected and some of them will die.  More handwashing and surface cleaning is futile while no measures are taken against air infected with Covid-19 from patients and staff who have the virus.  Wherever there is shared air, there is risk of transmission, and this includes non-clinical areas such as staff rest rooms, offices, change rooms, storage areas, reception and waiting areas etc.
  • To date seventeen NHS Trusts are known to have gone beyond the guidance and issued their staff with respiratory PPE to protect them and patients against hospital acquired infections.  The great majority of Trusts (there are 223) have not.  As this study comparing hospital acquired infections in the different trusts shows, the wearing of respiratory protective equipment by staff in contact with Covid patients, compared with wearing surgical masks, significantly reduces hospital acquired infections.
  • The same “droplet-not-aerosol” IPC guidance also applies to ambulance staff, i.e. they must wear surgical masks and not respiratory masks.  Ambulance workers are probably one of the most at-risk groups of health workers: they enter the homes of sick patients who are known to be Covid positive, who are often actively symptomatic (e.g. coughing and therefore producing large amounts of aerosols with virus into the air), and they are in the earlier stages of the disease which we know is the time of greatest Covid infectivity.  It is hard to imagine a scenario which is more high risk “red-zone” than this, yet staff are still issued poorly fitting surgical masks as standard.  Unsurprisingly in February 2021 the GMB union reported that one third of ambulance staff had been infected; it is likely that many more will have been since the onset of delta Covid. 
  • IPC guidance also gets the basic physics of aerosols wrong.  It states that only aerosols particles 5mm (microns) in size or smaller remain airborne.  This is wrong – particles up to 50-100mm can remain suspended and travel long distances through the air.  The bottom line is that the laws of physics greatly favour airborne transmission over droplet transmission – see here for a detailed explanation.  Despite fluid dynamics scientists (the people who proved airborne transmission and revolutionised our understanding of the transmission of respiratory pathogens) repeatedly pointing out that IPC doctors are flouting the laws of physics, IPC remains obdurate.
  • So glaring has been IPC’s intransigence on airborne transmission, there is now a growing literature being published on the matter, examining why this may be happening.  This recent paper is an interesting review of reasons, pointing to historical errors, scientific vested interests, ideological manipulation and do-the-minimum policy making, while this paper gives an international perspective of the origin of droplet-dogma and how it continues to bedevil current policy.

Published by