MPOX may be spreading silently in the UK, experts warn, as officials race to contain a looming crisis.
Three housemates living in London have already tested positive for the strain, never seen before in this country.
The mutation, dubbed Clade 1b, is believed to be more contagious than its predecessor and just as deadly.
Thousands of cases of the mutant disease and hundreds of deaths have already been reported in Central Africa where the outbreak started.
Two Brits carrying the bug have been placed under specialist care at Guy’s and St Thomas’ NHS Foundation Trust, the UK Health Security Agency (UKHSA) said on Monday.
They are understood to be members of the same household as the first person to test positive for the new strain after travelling back from Africa two weeks ago.
“Mpox is very infectious in households with close contact and so it is not unexpected to see further cases within the same household,” said Professor Susan Hopkins, from the UKHSA.
Top disease experts have warned they may be the first three of many.
“We can be almost certain that there will be undetected cases in the UK and other developed countries,” Dr Simon Clarke, an infectious disease expert University of Reading, told The Sun.
Dr Simon said mpox can fly under the radar because symptoms can be non-specific or mild, and the skin rash could be confused with a rash from other illnesses.
“There will be some people who carry the virus, who do not get sick but who can still spread it to other people and there may be some people who are about to get sick but who are shedding virus and are a risk to other people,” he explained.
“In either case, these people will likely go unnoticed by the authorities while posing a risk to other people.”
Prof Susan Hopkins, chief medical adviser at UKHSA, said: “Mpox is very infectious in households with close contact and so it is not unexpected to see further cases within the same household.
“The overall risk to the UK population remains low.
“We are working with partners to make sure all contacts of the cases are identified and contacted to reduce the risk of further spread.”
Professor Paul Hunter, an expert in medicine at the University of East Anglia told The Sun it was “certainly possible” that there have been “some” undetected infections in the UK.
However, he said this can not yet be proved.
“There has been some transmission within this one household.
While planning is underway in the UK to prepare for more cases, the superintendent pharmacist at Chemist Click, Abbas Kanani, has shared with The Sun the symptoms of mpox to look out for.
Mr Kanani said: “Around one to five days after the first symptoms, a rash on the face usually appears.
“Its appearance of raised spots and small blisters filled with fluid can be mistaken for chickenpox and tends to spread to other parts of the body including genitals, anus and mouth.
“Anal bleeding and pain may also be experienced.”
The most common symptom, according to Mr Kanani, is typically the skin rash which can last two to four weeks.
He said for some people the first symptom may be a rash, while others may have different symptoms first.
But one symptom commonly missed, Kanani warned, is swollen glands or lymph nodes.
He explained: “Swollen glands or lymph nodes can be commonly mistaken for other causes and are not always obvious, particularly if there is mild swelling or it is deep in the body.
“Also, this symptom can be missed because the rash tends to be the most prominent symptom of mpox.”
“But that does not mean there has been transmission elsewhere in the UK.
“There may have been but with the evidence we currently have we cannot say one way or the other,” he explained.
Meanwhile, the NHS says it has plans to expand the vaccine rollout to offer more people protection against the virus if necessary.
Mpox, previously known as monkeypox, spreads between people through direct contact with rashes, skin lesions or scabs caused by the virus.
This typically happens during sex, kissing, cuddling or other skin-to-skin contact.
There is also a risk from contact with body fluids such as saliva or snot.
Contact with bedding towels or clothing can also increase the possibility of spread. As can close and prolonged face-to-face contact such as talking, breathing, coughing or sneezing.
Clade Ib mpox has been widely circulating in the Democratic Republic of Congo (DCR) since April 2023.
But in recent months, the Clade 1b strain has reached other continents, including Europe and Asia.
Germany reported its first case of the mutant bug earlier this month, following Sweden’s first case in August.
There have also been cases reported in Burundi, Rwanda, Uganda, Kenya, Thailand and India.
Scientists are already concerned by how fast the new variant of the disease is spreading, and by its high fatality rate.
This prompted the World Health Organisation (WHO) to name the increasing spread of the disease a global health emergency for the second time in two years.
The Clade 1b is different from the Clade 2 strain that has been circulating in the UK since 2022.
The first UK case tested positive for the Clade 1b strain on October 29 in London and is believed to have contracted the virus while on holiday in an African country affected by the outbreak.
They were moved to the Royal Free Hospital in London, a high-consequence infectious diseases unit where people infected with Ebola have been treated in the past.
The NHS is offering the smallpox (MVA) vaccine to people who are most likely to be exposed to mpox.
People who are most likely to be exposed include:
The NHS mpox outbreak vaccination programme is currently only available in London and Greater Manchester, to people who live or travel to have sex there.
Healthcare workers will usually be offered two doses of the vaccine.
Men who are gay, bisexual or have sex with other men will be offered 2 doses of the vaccine. The 2nd dose will be offered from 2 to 3 months after the 1st dose.
Your local NHS services will contact you when you can get your 2nd dose
It was earlier this year when scientists first discovered Clade 1b.
They said that it may cause milder symptoms than Clade 2 which triggered the mpox public health emergency in 2022.
However, the new variant of the bug is believed to spread more easily through close contacts, according to Prof Thomas House, a Mathematical Statistics expert from the University of Manchester.
“Under the assumption that the current outbreak is equally infectious to the 2022 outbreak, a cluster involving two household infections should increase the credibility of the hypothesis that the current outbreak is more infectious in households than 2022,” he explained.
Mpox is a viral disease that occurs mostly in central and western Africa.
It was first identified in laboratory monkeys, according to the US Centres for Disease Control and Prevention (CDC).
Currently there is no treatment approved specifically for mpox virus infections, according to the CDC.
However, a two-dose vaccine has been developed to protect against the virus.
