My latest update on the background to the monkeypox scare.

UK Situation

1. As of the time of writing the UK has identified 71 cases. [4]
2. The vast majority of identified cases are isolating at home and do not require hospital admission. [1]
3. The closest contacts of confirmed cases are being offered the smallpox vaccine. This is the so-called “ring vaccination”. [1]
4. These closest contacts – anyone who has had direct or household contact with a confirmed case – are being told to isolate for 21 days (ie. the longest incubation period). [1,2]
5. The same high-risk contacts are advised to avoid immunosuppressed people, pregnant women and children under 12, as these groups are more vulnerable to serious infections. [1]
6. Contacts are being asked to provide their details for contact tracing. [2]
7. Sexual Health Clinics are still open for business, but are reported to be doing telephone triage. [4]

Global Situation

1. More than 131 confirmed cases are being investigated in 15 countries. [4]
2. More than half the cases are in Spain and Portugal. [1]
3. The WHO says the outbreak is “containable” and is providing advice to countries on how to tackle the situation. [4]
4. There seems to be some scaremongering (emanating from the NHS?) that you can be infected by eating meat. [5] Frankly, in my view, this is nonsense. Yes, in theory it may be possible to catch monkeypox from eating undercooked meat from an infected animal – which almost certainly means bushmeat. The chances of a food animal getting monkeypox and getting into the human food chain has to be vanishingly small.

Epidemiology

1. Genetic analysis of three monkeypox viruses from the outbreak have found it closely matches the virus that spread from Nigeria in 2018 and 2019. [1]
2. Monkeypox is less transmissible than SARS-CoV-2; the original Wuhan strain had an R₀ of about 2.5. Monkeypox has had R₀ under 1 in past outbreaks. [3]
3. A high fraction of SARS-CoV-2 transmission, maybe half(?), comes from people who aren’t showing symptoms at the time; whereas monkeypox transmission before symptom onset seems to be relatively rare, if it happens at all. [3]
4. The fact that very little if any monkeypox transmission occurs without symptoms means that if people start isolating once they begin to feel sick, they should be able to prevent almost all onward transmission. [3]
5. Moreover monkeypox spreads slowly (symptom onset is 5-21 days from infection) compared with Covid (symptom onset 1-4 days). [4]
6. This long incubation time gives contact tracers more time to identify contacts and set up ring vaccination. [3]
7. Putting that all together suggests that cases are unlikely to rapidly increase and get out of control. [3]
8. Studies suggest that a Belgian man contracted the virus on a recent trip to Portugal. [1]
9. The pattern of the outbreak suggests the virus is spreading primarily through sexual networks. [1]
10. Super-spreader events may have boosted the outbreak since it arrived in Europe. [1] This could be around the rave scene in Spain; a Gay Pride event in the Canary Islands is apparently being investigated. [6]
11. Cases are being found which have no identified contact with west Africa. [2]
12. Scientists have a big challenge as they currently do not know how many unreported cases there are; they’re currently seeing only the tip of the iceberg. [2]

References

[1] https://www.theguardian.com/world/2022/may/22/monkeypox-uk-health-security-agency-to-announce-more-cases
[2] https://www.bbc.co.uk/news/uk-61546480
[3] https://threadreaderapp.com/thread/1528450298901155841.html
[4] https://www.bbc.co.uk/news/health-61570562
[5] https://www.thisislocallondon.co.uk/news/national/uk-today/20159989.monkeypox-nhs-issues-warning-anyone-eats-meat-uk-cases-rise/
[6] https://www.thisislocallondon.co.uk/news/national/uk-today/20160206.monkeypox-outbreak-sex-raves-spain-belgium-may-blame/

Following up on my earlier comment about monkeypox being a DNA virus and different to SARS-Cov-2 (which is an RNA virus), I figured a bit more (very low tech) explanation may help. First off some very simple explanations. (Don’t worry if you don’t know what any of these things are; just think of them as “stuff” or “method”.)

Virus. A pseudo-cell basically composed of some minimal amount of genetic code (DNA or RNA) encapsulated in a lipid (ie. fatty) membrane. It is unable to reproduce on it’s own and has to hijack the machinery of a host cell to make more copies of itself.

DNA. This is the chemical code which holds all our genes. It is composed of the “double helix” of two strands of DNA twined round each other – think of two intertwined springs. In order for the cell machinery to read the text of the DNA the two strands have to be zipped apart and then afterwards zipped back together. Think of this as a whole jumbled box of knitting patterns

RNA. This is essentially a short piece of code created from a piece of a single strand of DNA; it typically provides the instructions for making a single protein. Think of it as a single knitting pattern, extracted from that box of patterns.

Transcription is the process of unzipping the DNA and copying it to make the RNA; this happens only in the cell nucleus (the strong box which holds the DNA). As in all copying, errors can creep in. So the machinery in the cell nucleus contains a proofreading function which finds the errors and discards the overwhelming majority of them.

There are essentially two types of virus, characterised by how they store their genetic information: DNA viruses and RNA viruses.

DNA viruses (for example, monkeypox) have to insert their genetic code, held as DNA, into the cell nucleus, as that’s the only place where it can be transcribed into RNA. So transcription errors are booted out by the proofreading function and mutation happens very rarely.

RNA viruses (for example, SARS-Cov-2 and flu) don’t have DNA; their genetic code is held as RNA. RNA doesn’t use the cell nucleus for transcription and hence can’t take advantage of the proofreading function. So transcription errors don’t get weeded out and mutations happen very frequently.

The process of using RNA as a blueprint to make proteins etc. is called translation.

And that is an incredibly simplified description of the processes. The details are hideously complex, so hideously complex one can quite see why some people find it hard to believe this has arisen through evolution.

Here’s an equally very simplified diagram (what I drew) of the processes.

So that hopefully shows why Covid-19 is dangerous, why we need a new flu vaccine every year, and why we hopefully don’t need to be too worried about monkeypox.