A new form of mpox is spreading in the Democratic Republic of Congo (DRC), raising fears it could spread to Europe.
The clade 1b mutation, which experts call ‘ the most dangerous one so far’, is believed to be behind a wave of miscarriages, and kills one in ten of those infected.
Scientists tracking the spread of the new strain have already warned it appears to be the most transmissible yet and could even end up in Europe.
So just how worried should we be, who is most at risk, and what, if anything, should we do to protect ourselves?
Here MailOnline explains everything you need to know.
Mpox, formerly known as monkeypox, is a rare viral infection which people usually pick up in the tropical areas of west and central Africa. Pictured, a colorized transmission electron micrograph of monkeypox particles (green) found within an infected cell (pink and purple)
What is mpox?
Mpox, formerly known as monkeypox, is a viral infection once mainly confined to west and central Africa.
It was spread to humans through direct contact with animals such as squirrels, which are known to harbour the virus.
However, it can also be transmitted through very close contact with an infected person.
The virus was first discovered when an outbreak of a pox-like disease occurred in monkeys kept for research in 1958, hence the previous name.
The first human case was recorded in 1970 in the Democratic Republic of Congo and the infection has been reported in mainly central and western African countries since then.
In 2022, an outbreak in Europe and the US that largely affected gay and bisexual men, prompted the World Health Organization (WHO) to declare a public health emergency.
It was the first time mpox had been reported to have primarily spread via sexual contact.
What is the new strain?
Clade 1b is a descendent of the deadly clade 1 strain of mpox and different than the milder version (clade 2) which spread to more than 20 countries, including the UK, in 2022.
Once again, sexual transmission seems to be the primary way clade 1b is spreading, and researchers believe the current outbreak began in a bar used by sex workers.
The disease first appeared in the rainy season when the roads were bad and there was limited movement of people between towns and villages.
Scientists warned the current dry season could see more transmission, particularly during school holidays as people circulate more.
At a briefing for journalists yesterday, Trudie Lang, professor of global health research at Oxford University, said when the DRC outbreak was detected last September scientists had assumed it would be clade 2, because of the sexual transmission.
However, genetic testing revealed it belonged to the more virulent strain.
Clade 1 has historically only been found in people who eat infected bushmeat, with transmission largely confined to the affected household.
How is it different to other strains?
Scientists have warned the strain was ‘undoubtedly’ the ‘most dangerous one’ yet.
It is also not clear how fast the new strain spreads.
Like Clade 2, Clade 1b causes a severe blister-like rash at the site of the infection.
But symptoms are more severe, with the rash often spreading to the entire body.
So far, around 600 patients with the mutant form of the virus have been identified in Kamituga — the town where it was first spotted.
Leandre Murhula Masirika, the research co-ordinator in the health department in South Kivu province — in the east of the nation — said 24 of the country’s 26 provinces were affected by the outbreak.
Experts, however, warn the real figure could be far higher, given hospitals are only logging severe cases that require advanced care.
The number of asymptomatic cases or people with minimal symptoms, who could still potentially spread the infection, is also still unknown.
Where has the mutant form of the virus been found?
Cases have, so far, all been reported in DRC towns bordering the nations of Rwanda, Burundi, and Uganda.
After clade 2 sparked alarm among health officials globally in 2022, new infections gradually tapered off amid boosted awareness of the disease and a hurried vaccination program. At the time the UK reported almost 4,000 cases, with NHS England inoculating over 68,000 people against the disease with the smallpox vaccine. Pictured, long lines to receive the vaccine
The smallpox vaccine works due to the two viruses being closely related. But experts said there wasn’t yet enough evidence to suggest a vaccine would be effective against this new strain
However, scientists said it was highly likely the virus has already reached these neighbouring countries, although no cases have been confirmed anywhere other than the DRC.
John Claude Udahemuka, a lecturer at the University of Rwanda who is monitoring the DRC outbreak, said they believe the first person with the new strain was a man who had sex with a woman in the town of Kamituga.
He then met with other women in several different locations.
Sex workers regularly travel between the DRC and its neighbours, meaning this could be a potential route of transmission, the scientists cautioned.
How deadly is it?
Mpox is usually not serious, with most patients recovering within a few weeks without treatment. Yet, the disease can prove fatal.
Early estimates suggest the new mutant strain has a mortality rate of five per cent for adults and 10 per cent for children.
But another worrying aspect was infection in pregnant women was causing an ‘alarming’ number of miscarriages.
Experts also said some cases had even resulted in irreversible sight loss, as well as recurrent whole-body rashes.
Earlier this month, the WHO said the mpox outbreak in DRC was ‘concerning’.
It pointed to limited public awareness of mpox, a lack of treatment kits and vaccines and the country’s many other health priorities as factors in the appearance of a new strain.
The risk associated with mpox in DRC ‘remains high’, it said.
How does it spread?
Mpox is not classified a sexually transmitted infection, though it can be passed on by direct contact during sex.
Contagious lesions, through which infections are most likely to be passed on, can appear on any part of the body.
The infection can also be passed on through contact with clothing or linens used by an infected person.
What are the symptoms people should be aware of?
Initially, mpox causes a flu-like illness: fever, headache, sore muscles, back pain, swollen lymph nodes (glands found in the neck, groin or under the arms) and fatigue.
Within one to five days, a rash appears, usually first on the face, then spreading to other parts of the body, including the genitals.
The rash is similar to chickenpox. It starts as raised spots that then turn into small fluid-filled blisters. These blisters turn into scabs, which eventually fall off.
The illness can last up to four weeks, but most cases clear up on their own without any treatment.
During the last outbreak, the UK Health Security Agency advised anyone with unusual rashes or lesions on any part of the body – in particular, gay or bisexual men, those who have been in contact with someone who has or might have mpox, and anyone who’s travelled to West Africa in the past three weeks – to contact NHS 111 or phone their local sexual health service.
What happens if someone does test positive in the UK?
If a person is suspected to have monkeypox in the UK, they usually will be given a PCR test – similar to the ones that were used to pick up Covid.
These use swabs taken from the skin and throat.
There are no specific treatments, and the NHS currently says if symptoms are mild, patients may simply be advised to stay at home until they recover.
If the illness is more serious, patients may be offered treatment including antiviral medication — Tecovirimat, which was designed for smallpox, and Cidofovir.
Will the current vaccine work against it?
After clade 2 sparked alarm among health officials globally in 2022, new infections gradually tapered off amid boosted awareness of the disease and a hurried vaccination program.
At the time the UK reported almost 4,000 cases, with NHS England inoculating over 68,000 people against the disease with the smallpox vaccine.
This works due to the two viruses being closely related.
But experts said there wasn’t yet enough evidence to suggest a vaccine would be effective against this new strain.
Trials will be needed to work this out, which will take time, they added.
