With the world opening up, it’s only a matter of time before cases of monkeypox are found in New Zealand, infectious disease physician Dr Massimo Giola says.
The World Health Organisation (WHO) has confirmed more than 90 cases of monkeypox in places like the United States, Australia and in several European countries.
So what is monkeypox?
"Monkeypox is, like the name implies, a poxvirus. It is quite closely related to smallpox and in fact, is now the most frequent cause of human pox infections,” University of Otago infectious diseases physician Kurt Krause says.
Monkeypox is less contagious than smallpox and causes less severe illness.
Smallpox was a disfiguring illness that had a 30% mortality rate and was estimated to have killed 300 to 500 million people before it was eradicated in the 1980s.
While smallpox only infected humans, monkeypox is an animal virus that occasionally infects humans after they are bitten or scratched by a monkey or other animal.
That’s why it’s called monkeypox.
Monkeypox is usually considered ‘endemic’ for Central and West Africa which means it is mainly found there but since 2013 there have been several outbreaks worldwide.
What are the symptoms of monkeypox?
Fever, flu-like symptoms and rashes are tell-tale signs of monkeypox, University of Canterbury associate professor of epidemiology Arindam Basu says.
The incubation period (interval from infection to onset of symptoms) of monkeypox is usually from 6 to 13 days but can range from 5 to 21 days.
Monkeypox is a self-limited disease with symptoms usually lasting from two to four weeks.
‘Self-limiting’ means it goes away on its own with or without specific treatment like colds or conjunctivitis.
Dr Massimo Giola, who is also a sexual health physician, says another thing to be aware of is in sexual health clinics, rashes or lesions on someone’s palms or soles are typically associated with syphilis.
“The problem is that monkeypox gives you exactly the same presentation.
“The only clinical characteristic that seems to differentiate monkeypox from syphilis is that typically in syphilis, the lesions are not painful. Whereas in monkeypox – from the little we know about it – the lesions seem to be exquisitely painful."
How is monkeypox spread?
Krause says monkeypox can pass through skin-to-skin contact with lesions as well as through droplets, bodily fluids and saliva.
Because skin-to-skin contact is a key way for monkeypox to be transmitted, very close contacts and health workers are most at risk.
It does not spread easily through humans like Covid-19.
“It is less contagious than Covid-19 and the outbreaks are much smaller,” Krause says.
"One reason the disease is less contagious is that people are often stricken with a very large number of quite visible pox lesions and it is then readily apparent that the affected person is ill. So inadvertent transmission is less likely.
“However transmission is possible, it’s just that the R0 values (rate of transmission) are often found to be less than 1 and the outbreaks die out.”
Due to the way monkeypox is spread and recognised, it is unlikely there will be a massive outbreak like Covid-19, Krause says. Outbreaks generally affect 100 to 200 people and then go away.
Is there a vaccine for monkeypox?
Giola says "monkeypox is a relative of the smallpox virus, which was eradicated through a worldwide campaign of mass vaccination”.
So people born before 1970 are vaccinated against smallpox.
According to the WHO website: “Vaccines used during the smallpox eradication programme also provided protection against monkeypox. Newer vaccines have been developed of which one has been approved for prevention of monkeypox.”
Because smallpox vaccinations are no longer routine, at the moment no one is being vaccinated for it.
However the United States has already purchased 13 million doses of monkeypox vaccines after cases were confirmed in New York.
How dangerous is monkeypox?
There are two main types of monkeypox - one is more dangerous and has a 10% death rate while the Western African strain in this outbreak is less severe and has a death rate of 1% or less.
Is monkeypox sexually transmitted?
There is a question around whether monkeypox is sexually transmitted, Giola says.
“There are a few diseases - for example scabies and meningococcus - like this that given the right circumstances behave like sexually transmitted diseases even though they're not normally classified in that group. For example kissing could cause transmission through saliva.”
Most of the current cases seem to have occured among gay and bisexual men, Giola says.
“We know that gay and bisexual men are a canary in the coal mine of infectious diseases and particularly sexually transmitted diseases. The reasons for that are quite complex.”
Giola says gay and bisexual men are a minority in the general population meaning there are “dense sexual networks”.
“As we say in the gay world, we are all family. That means if you get an STI into those dense sexual networks, then that will spread like wildfire, much more than in the heterosexual population.”
“With a sexually communicable disease, that makes it possible to infect more than one person allowing the epidemic to expand,” Giola says.
“Another thing I'd like to mention is around gay men and international travel. A number of reasons – that range from having more disposable money, not having kids, to having a more widespread international network of dedicated places to go to for holidays – make it very easy and very fast to spread infections among gay and bisexual men over the four continents.”