“It’s not spread by monkeys,” says Brian Ferguson, a professor of virology at the University of Cambridge. “It’s called monkeypox, but it’s from rodents.”
The rise of a new disease out of animal populations in the developing world is probably the news that the world least wanted to hear. Covid is not over but, in the UK at least, we are reaching a point where we can behave as though it is. So the news that 57 people in the UK have been diagnosed with monkeypox, and around a hundred worldwide in at least 14 different countries, is understandably unnerving.
But while it’s understandable, the situation is extremely different from the rise of Covid. It’s a serious situation that public health bodies and governments should take seriously, but we’re not looking at a global disaster.
What’s causing the sudden spread?
Monkeypox, as Ferguson points out, is not really very much to do with monkeys. It’s a pox virus endemic in Central and West African rodent populations, and which sometimes leaps across to humans. (It was first detected in a monkey – it can infect them – hence the name.) It’s related to smallpox and cowpox, and like those diseases causes unpleasant rashes. But it’s far less deadly than smallpox, and not especially brilliant at spreading from human to human.
When the first cases were detected, in several countries and in people who had not apparently travelled abroad, there was concern that it was a new mutant variant which had become much more transmissible. But that’s probably not the case, according to Ferguson.
“Pox viruses have a large genome compared to other viruses,” he says. “About 200 genes [compared to about 15 for SARS-Cov2].” Each of those genes is made of thousands of “letters” of DNA, and each gene tells your cells how to make a protein out of a long string of amino acids. Genetic sequencing of the virus from the recent cases shows that only about 20 of those amino acids have changed since the last UK monkeypox outbreak, in 2018.
“Overall the genome is not massively different,” says Ferguson. “It doesn’t look like a huge leap in transmissibility. There may be some subtlety – the functions of the genes aren’t known in great detail – but there’s nothing obvious that makes us think that this virus is really different.”
Similarly, he says, the pathology of the virus, the symptoms it causes and the course the disease takes in a patient, “looks similar to what’s been observed in outbreaks in Africa.” There may be differences, but if there are they haven’t been spotted. It’s worth being cautious but the best guess is probably that we’re not looking at a new and especially dangerous virus.
The question is, if the disease itself hasn’t changed, what’s driven the sudden spread? The most likely explanation is a superspreader event in which multiple people were infected, and then went on to infect other people.
That’s the theory put forward by a leading adviser to the World Health Organisation (WHO), David Heymann. He says that most of the cases can be traced back to two raves in Spain and Belgium.
After that, it seems to have spread mainly among gay and bisexual men, driven by sexual contact at gay saunas. It’s important that this is understood, because men in that community will be at higher risk. But it’s also important to recognise that this isn’t a “gay disease”.
By analogy, imagine that a researcher had picked up monkeypox before going to an international academic conference. He or she might spread that disease around dozens of their academic colleagues, and those colleagues might spread it further in their departments or other conferences. But we wouldn’t think of it as an “academic disease”. Non-academics can catch it, and the fact that it has spread among academics is at least partly just chance.
The analogy isn’t perfect – the disease is spread by close contact, especially skin contact, so of course sex is a good way to spread it. But it’s not a sexually transmitted disease, and it certainly isn’t a “gay disease”.
Stigma will make it harder to stop
There is always a tension between making it clear that a disease is most prevalent among particular groups that, and not stigmatising those groups. Gregg Gonsalves, a professor of epidemiology at Yale University, points out that during the rise of the Aids epidemic in the 80s, William F Buckley wrote in the New York Times that HIV-positive patients should have their buttocks tattooed to warn others.
“This is catnip for the tabloids,” he says. “Responsible journalists and the Government have to be crystal clear about the potential for anti-gay violence and harassment that comes from ginning this up as a gay plague.”
“You get people not coming forward because they feel stigmatised,” agrees Ferguson.
But on the other hand, it’s also important to get the information to at-risk groups, so that they can seek treatment and help contain the spread. “The important thing is that you have to find the people who’ve been in touch with people who’ve had the disease, in order to stop it spreading further,” Ferguson says. “If they have a rash anywhere on their body. People have to be comfortable coming forwards.”
As much as anything else, that’s because containing this disease – much more even than with Covid – will be about contact tracing, and “ring vaccination” techniques. Smallpox was eradicated because whenever a case was detected, doctors and nurses rushed to the area and vaccinated everyone who’d been in contact with the patient, and then everyone who’d been in contact with those people.
Vaccination works even a few days after contact, so doing it quickly can very effectively stop the spread. Monkeypox is sufficiently similar to smallpox that the same vaccine – derived from the cowpox vaccine, vaccinia – works to prevent both.
In fact, the success of humanity’s fight against smallpox is probably the reason why monkeypox is spreading now. Up until about 50 years ago, every British child would have been routinely vaccinated against smallpox. But by 1971, with the disease all but eradicated, it was deemed no longer worth the effort.
That has meant that many of us no longer have the antibodies we would have done, and so monkeypox spreads more easily. “That’s been flagged for decades by people working on zoonotic diseases,” says Ferguson. He notes that a paper a few years ago suggested that an outbreak of monkeypox was more likely now. That doesn’t mean we were wrong to stop vaccinating – it may have reduced the chance of this outbreak, but it would have been costly and difficult, and governments only have so much money to spend on public health. But it’s worth being aware of.
This is absolutely not a new Covid
But even if it is spreading more easily, it’s still not something that the population at large needs to worry about very much. “It’s relatively hard to transmit from person to person,” says Ferguson. “It’s not like Covid – omicron is almost impossible to avoid, but it’s possible to avoid transmitting monkeypox.”
And it’s not very deadly. It’s hard to be sure, because you can’t get a good sense of what percentage of infected people die without knowing the real number of people infected, and the data collection in the West and Central African countries where monkeypox is endemic is not always perfect.
If patients are left untreated, then it can be dangerous – perhaps a single-digit percentage of infected people might die, at a worst-case scenario – but “with decent healthcare, it’ll likely resolve and you’ll be fine”, says Ferguson. Simply making sure the patient doesn’t get dehydrated or catch any secondary infections should be enough to drop the fatality rate to a fraction of a percent, he thinks.
“I don’t want people to get the impression that this is a disease that’s worth a ton of fear,” he says. “It’s not as bad as Covid in any way. It’s not pleasant, and it’s important that we do everything we can to stop it, but it’s not going to kill millions of people.” Unlike with Covid, it is more dangerous to children than to adults, but even for children the absolute risk is low.
With Covid, there was a tendency in the early months to understate the risks, out of a worry of adding to anti-Chinese racism. It was an understandable concern, but it led in some quarters to a kneejerk dismissal of the very real dangers.
But with monkeypox, we need to be careful to avoid making the opposite mistake. The chances are that it is a far less deadly disease, and far less transmissible, than even the original strain of Covid. It is spreading, mainly, among men who have sex with men.
It’s important to get the message to that community that they should be on the lookout for any unusual rashes, and that they should tell their GP immediately if they see one.
But it is not a “gay disease”, and if society stigmatises it as such, we may make it harder for people to come forward. And we need them to come forward for ring vaccination to work. So the government, and the media, needs to avoid any suggestion that groups or individuals are to blame.