I still have no regerts… (sic) part 2

This second part of a blog considers the World Health Organisation’s (WHO) most recent attempt (bargaining position) to evidence newly proposed modes of respiratory transmission. During the early stages of the pandemic, I had what so many others did not – time. I had time to review the claims in guidance and the citations used to support them. I was shocked at the number of times the citations did not evidence the claim.  For example, in a global report on ‘Infection Prevention and Control, 2022’, the WHO used two citations to support their claim that “…hand hygiene has been highlighted as the most effective single measure to reduce transmission…”. The two citations (38 & 39) neither mentioned hands nor their hygiene.  Now, from time-to-time people use the wrong citation(s) – some do it as a deliberate lazy act. Others do it from a bias to an existing favoured paradigm. Clearly, it is unacceptable as a routine violation. We should defer to the WHO as an expert body, without feeling obliged to check if the claims are supported by citations – but here we are…

The new World Health Organisation document needed citations to back up what they had previously called droplet transmission and now call ‘through the air via direct deposition’. They used 25 citations to do this.

[IRPs = infectious respiratory particles].

These 25 citations should provide support about the Ways Out, how the infectious respiratory particles behave after exit, and confirm that the particles are deposited directly following a semi-ballistic trajectory onto facial mucous membranes where they enter the respiratory tract to infect.

Having read the 25 papers, they evidence the following:

  • 4 Studies are about particles at exhalation – the Ways Out [38, 53, 54,102].
  • 11 Studies are about respiratory particle behaviour after exhalation – but before direct deposition [42, 52, 62, 72, 84, 95, 97, 98, 100, 101,105].
  • 2 Studies present plausible evidence of the Ways In via Direct Deposition, but it is unconfirmed if this was via a ballistic spray:
    • In a review of outbreak studies, 3 reports were identified where tears or conjunctivae were positive. This is only considered plausible for deposition from a ballistic spray as the positive swabs could have resulted from hand transfer from an already infected person to their eye(s) [41].
    • One review identified inoculation studies where viruses in solution were inoculated on intra-ocular and/or intra-nasal surfaces resulting in infections. This is also only considered plausible as the experiments involved a dropper and not a ballistic spray trajectory [76].
  • 4 Studies evidenced Ways In via inhalation (but not direct deposition from a ballistic spray) [47, 99, 103, 106].
  • 2 Studies claim evidence of direct deposition, but this was the error of interpreting close to a source as evidence of droplets [47, 58.]
  • 3 Studies were not about mode of transmission [48, 67, 104].

[One study, 47, is in 2 categories.]

Absolute evidence for direct deposition via a ballistic spray was, therefore, absent in the WHO’s 25 citations. However, the WHO did evidence through the air via inhalation (airborne) in four citations and in an additional two studies used to support through the air via inhalation [63,93]. Based on the WHO’s presented citations, airborne via inhalation is evidenced, droplet deposition is only plausible, ergo, healthcare workers (HCWs) caring for infectious people still need respiratory protection equipment (as they always have).  The WHO, having the humiliation of advocating unevidenced definitions during the early phase of the pandemic, now proposes definitions without a full literature review. This is incomplete and unsafe. For example, the Amoy Gardens outbreak most likely happened as a result of the inhalation of a faecal plume – unconsidered by the WHO in their latest piece on definitions.

Both direct deposition and inhalation happen at short-range and at this distance transmission by either cannot be distinguished, ergo, there can no longer be a default to droplet transmission. Transmission which happens outwith direct deposition range should lead to a default to airborne via inhalation, e.g., when there has been no contact with an infected case or common surfaces, when the infectious person is asymptomatic (no ballistic spray), and especially when such evidence is given credence by whole genome sequencing. Such studies could be called ‘Sherlock Holmes Airborne’ as to mis-quote from his Sign of Four:

“When you have eliminated the impossible [transmission routes, the route(s)] which remain, however improbable, must [include or] be the truth”.

Examples include the recently reported outbreak where whole genome sequencing identified that two people who used the same room after someone infectious left up to 4-hours prior to their admission, could only have acquired the virus via inhalation. Another example is the outbreak where without contact the virus spread backwards on a bus. [Of note, Fennelly also reported that most of the pathogens are in the smallest particles and most transmission is airborne].

The WHO erred in stating that droplets (direct deposition) were dominant (March 2020, July 2020). They promoted that close to a source indicated droplets (and airborne was only evident at distance or via AGPs). The use of the term ‘close contact’ was also misleading – close contact is a space where transmission happens – and not a route itself. There are no close contact precautions. What the WHO (and others) failed to consider (or accept) is that close to a source transmission is more likely to be airborne as this is where the aerosols are densest. Additionally, droplets containing virus in ballistic sprays either shrink to become aerosols or drop quickly to negate a through the air potential deposition risk. In contrast aerosols remain in the air – to be potentially inhaled hours after being exhaled.

Although the WHO has admitted short range airborne, they have failed to admit that the dominant route – airborne via inhalation. Their prior insistence of this being droplets has prevented a focus on clean air as well as effective respiratory protection equipment. However, the above indicates the default and dominant route of transmission has effectively been reversed to airborne via inhalation.

So, who gets to decide if the WHO bargain is accepted. Well, I don’t think it’s me. The question is whether this biblical scale ‘Never Event’ by the WHO is wipe-the-slate-clean forgivable. It’s hardly a case of don’t sweat the small stuff. There could not be a greater error than for the WHO to mislead the world on the mode of transmission during a pandemic (whether by ignorance or purpose), and then to attempt a rewrite of history. Are the WHO too big to regret, reason and remedy their way out of this biblical scale Never Event? The WHO are certainly giving it a go. If the WHO (or more reasonably its senior IPC decision-makers) can have the slate wiped clean for mis-leading the world, then the world also accepts that the WHO does not need to conform to scientific and ethical principles, the world can expect a likely repeat event, and the WHO has neither a need to improve nor honestly investigate its mistakes. Finally, if they achieve this, the WHO will forgo any future claim of integrity. That is too much for me.

So here’s my claim, based on the evidence provided by the WHO, there is a plausible case for droplet deposition, but a clear evidenced claim for inhalation, and for this inhalation route to be the dominant mode. Ergo, HCWs need respiratory protection against inhalation of the virus and recommendations to clean the air must be made.  Either this claim is true, or the WHO is hiding a mountain of evidence of direct deposition unavailable to the rest of us.

Finally, there should have been a full literature search examined before proposed definitions were written and issued for considerations.

Dr. Evonne T Curran NursD. Rtd RN

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