The spread of monkeypox in countries where it isn't usually found is – understandably – concerning a lot of people around the world. The Detail speaks to two infectious diseases experts about what the disease is, how it spreads, and how concerned we should be.
How worried are health officials?
First things first: monkeypox. How serious a threat does it pose? Is it in anything like the same category as Covid-19?
"Completely different category," says Professor Kurt Krause, an infectious diseases expert at Otago University.
"I think it's very unlikely to cause anything like Covid-19.
"It may be that New Zealand ends up with a few cases, but for New Zealand to end up with a large outbreak, I'd be surprised, and it would be extraordinarily unlikely for it to be a population-wide outbreak. That would floor me completely."
What is monkeypox?
Monkeypox is a pox virus, and similar in its makeup to smallpox.
In fact, ironically, the success of the smallpox vaccine in eradicating that devastating illness may be partially to blame for this monkeypox outbreak.
Because smallpox was eradicated in the early-1980s, people aren't routinely vaccinated against the disease these days, and some public health officials hypothesise this may have left some populations at greater risk of illnesses like monkeypox.
It manifests in a series of increasingly identifiable symptoms, says Krause.
"There's a prodromal period where [monkeypox] causes fever and headache. In the case of monkeypox people will get swollen lymph nodes.
"After that a rash forms, these pox-like lesions form. In monkeypox the lesions tend to occur on the face first, and then spread to the chest and other areas.
"They can enlarge, coalesce, and sometimes burst open. Over three to four weeks, they crust, and then eventually recover."
Krause says of the two types of identified monkeypox – Western African and Central African – the Western strain has a much lower mortality rate, of around 1 percent, compared to the Central strain, which is around 10 percent.
However, he cautions that these are fatality rates of reported cases, and the actual fatality rates are likely higher.
Monkeypox spreads through close skin-to-skin contact with people with infected lesions, through respiratory droplets (though not aerosols), and through fomites – contaminated clothes or objects.
The over-representation of men who have sex with men
One notable facet of the international outbreaks of monkeypox is that they appear to be disproportionately affecting men who have sex with men.
This has led the UN to reproach some media for oversimplified reporting which might suggest this is a sexually transmitted disease largely confined to gay and bisexual men.
Massimo Giola, an infectious diseases expert and sexual health physician, says this is par for the course, and men who have sex with men are often the ‘canary in the coalmine’ when new infectious diseases crop up.
"I know what people are thinking – 'it's because those naughty and promiscuous gay men have sex with anyone in their proximity'," says Giola.
"That's not the case, I'm sorry to disappoint. When you look at the total number of sexual partners in a lifetime, gay men are no different from anyone else.
"There is a little bit more of what we call in sexual health 'concurrent partnerships': having, in a short amount of time, two or three sexual partners.
"It's a small difference, but we think that small difference is possibly enough to sustain better transmission of sexually transmitted diseases.
"Plus, gay men are the minority of the population, and therefore our sexual networks tend to be more dense.
"And then, finally, gay men in many countries face stigma and discrimination. So, we tend to congregate in safe places…and, of course, there will be a lot of us at the same time in the same place."
Giola says there is nothing radically different about the sexual behaviour or biological makeup of gay and bisexual men that make them more prone to transmitting infections.
"From a point of view, we are actually servicing the community by acting – involuntarily, of course – as the canary in the coalmine."
Giola says the point about gay and bisexual men seeking safe spaces and having more dense sexual networks is, in fact, the leading theory as to why monkeypox has spread to a number of disparate countries in a short period of time.
At the time of our interview, the Spanish government had noted 22 of its 23 cases of monkeypox were gay men, and linked this to a large gay pride festival in the Canary Islands, attended by some 80,000 people.
"If that was the case, and there is no more ongoing transmission…we might get on top of the outbreak reasonably quickly," Giola says.
Where to from here?
Kurt Krause says at this point in time, the outbreak is more a cause for concern than alarm.
"I'm not panicking, because it's very, very likely the monkeypox we're seeing now is the same monkeypox we've seen in prior outbreaks."
However, Krause says it's possible this strain of monkeypox has morphed into something more contagious – and potentially dangerous – and that's why it's crucial to sequence the genome as soon as possible.
"I would be surprised if there was a major change, but let's find out."
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