Avian influenza A subtype H7N7 has killed one person, and is classified as a “High Consequence Infectious Disease”. COVID-19 has killed 10 million, and is not

A year ago I wrote – with some surprise – of the UK government’s decision to downgrade the classification of COVID-19, so that it was no longer considered a “High Consequence Infectious Disease” (HCID). This was done right at the beginning of the pandemic in the UK, spring 2020. Very early on, COVID-19 was classified in this most-dangerous HCID category, but it was then downgraded. But I don’t think I was surprised enough.

The list of HCIDs, as of today (10th April 2022), is:

Note that “contact” and “airborne” refers to how they are believed to (predominantly) spread, and that the SARS above is the first SARS, from 2003/2004. This is a virus closely related to SARS-CoV-2, which causes COVID-19, but it is not the same.The first SARS is more deadly if you are infected, but is much less infectious – which is why it did not cause a global pandemic.

Now, the list above contains some scary diseases. Ebola kills about half those infected, much higher than COVID-19, which was closer to 1% even before vaccines. What I had not appreciated is that the list also contains some less scary (relatively speaking) diseases, such as the H7N7 subtype of avian influenza (bird flu) A. There was an outbreak in The Netherlands that infected a little less than a hundred, of whom one died, and a smaller one in Italy, in which nobody died.

By contrast, at the time of writing, the World Health Organisation reported half a billion infected, and six million deaths*, from COVID-19. This is a comparable mortality rate (1%) to H7N7, but half a billion infections, not a hundred.

The definition of an HCID (as of 10th April 2022) is:

It is hard to see why COVID-19 does not meet these criteria, while H7N7 does.

A Health and Safety practitioner, David Osborn, made this point in his evidence to a House of Commons Health and Social Care committee hearing on the pandemic. It may be that the decision to downgrade COVID-19 from HCID was taken, at least in part, so surgical masks could be recommended for healthcare workers, not FFP3 masks, which offer much more protection. If so that is disappointing. Many healthcare workers – while presumably wearing surgical masks – have caught COVID-19 when they were doing their job, and some of these people have died.

* These figures are those reported to WHO, the true figures are higher.