PROFESSOR Rowland Kao is the chair of veterinary epidemiology and data science at Edinburgh University. The biologist has done extensive research into infectious disease dynamics, studying the spread of illnesses like BSE, avian flu, bovine tuberculosis and food and mouth disease among many others. Here, the professor (below) answers your most pressing questions on the outbreak of monkeypox in the UK – after Scotland confirmed its first case on Monday.
Why is monkeypox suddenly spreading?
We don’t actually know. There is no obvious change in the virus itself (though it is difficult to be sure on this, as there is no strict "one-to-one" correspondence between evolutionary change and changes in transmissibility), and also no immediate evidence which suggests the conditions for transmission have changed.
It could be that a number of small changes in behaviour and activity have resulted in a "burst of cases" in some high risk communities. It has been noted, for example, that many of the cases involve men who have sex with men – as prolonged close physical contact is likely a risk for transmission (unlike SARS-CoV-2 for example, where small air droplets are believed to be a big risk, this has not been known to be a risk for monkeypox), this means that if it enters into groups of individuals where there is a high level of sexual activity, this can result in rapid spread. That rapid spread may cross between countries (more likely now that international travel is increasing again).
Does it come from monkeys?
It was first discovered in monkeys, but is also known to infect a wide variety of species including many rodents. Prior to this current wave of infections, most human infections came from animals. One of the largest prior outbreaks occurred in the USA in the early 2000s, where the source of infection was likely pet prairie dogs, who in turn were infected by exotic imported pets (rodents).
How long does it take to recover from monkeypox?
Most cases of monkeypox are relatively mild. The duration of infection is probably on the order of weeks but less than a month. This prolonged period of being affected also likely means that infected individuals may be infectious for quite a long time – which both means it can be difficult to trace, and also means that, a single infectious individual may be involved in multiple superspreading events.
Are we going to end up in another lockdown?
This is extremely unlikely. First, there is no evidence yet that sustained transmission in human populations is likely – this will be even less likely as awareness of the disease and its symptoms becomes greater. Even if sustained transmission from person to person were to occur, the virus itself does not transmit so easily as for SARS-CoV-2, so the extreme measures are unlikely to be necessary, though it is possible that some community level measures might be put into place. They would however be nothing like lockdown.
Will we need a new vaccine?
The vaccines that resulted in the eradication of smallpox have historically been very effective against monkeypox and are likely to be quite effective here. Of course better vaccines could also be developed but for the moment, there is no clear mandate for vaccinating given that the numbers infected are currently small. The probability of the current vaccines causing severe side effects is very small, but is a consideration – you would only want to use the vaccines, when the risk of getting infected are higher.
Why do doctors say they've been predominantly identifying community-transmitted monkeypox cases in individuals who self-identify as gay or bisexual?
There is no evidence that it is more likely to transmit amongst this group. Monkeypox transmission likely requires close contact for prolonged periods. As transmission via direct contact is related to clinical symptoms (the development of pustules on the skin), this means that it will have many of the characteristics of sexually transmitted infections. What that means is that, once introduced into particularly communities, it then becomes more likely to continue to circulate in those communities. It is most likely that women and heterosexual men are are likely to get infected, should they engage in similar levels of prolonged close contact with infected and infectious persons.
What action can the Government take to help the situation?
A critical consideration is awareness of symptoms and encouragement for individuals to contact health services should they have any suspicion of infection. Rapid contact tracing where infection is identified is critical to preventing spread, especially given the long duration of infection, once infected.
