Mpox could be spreading silently in the UK, experts fear as officials scramble to contain a potential crisis.
One Briton has already been sickened by a strain never before seen in this country, which kills one in 10 infected people.
The mutation, called clade 1b, was detected after the unnamed patient traveled to the UK from a holiday in Africa on October 21, before developing symptoms a day later.
The patient has been moved to a high-level isolation unit at the Royal Free Hospital in north London.
But top virus doctors have told MailOnline the first patient is likely to be one of many.
‘“It is very likely that there are undetected cases of mpox clade 1b in the UK,” said Dr Azeem Majeed, a public health expert at Imperial College London.
Meanwhile, other specialists described the rampant spread of the virus as “inevitable”, adding that it is “very likely” that several cases have gone undetected in the UK for weeks.
Yesterday, bosses at the UK Health Security Agency (UKHSA) revealed they do not know how the person diagnosed with the disease contracted the strain, but investigations are “underway”.
They urged Britons not to panic and said the threat clade 1b poses to the public was “low”.
The patient has been moved to a high-level isolation unit at the Royal Free Hospital in north London, the same facility where imported Ebola cases were treated in 2015.
Dr. Majeed said mpox can go unnoticed because the symptoms can be nonspecific or mild, and the skin rash could be confused. with rash due to other diseases.
“It can even be asymptomatic,” he added.
It is “essential,” he said, that there be “rigorous surveillance” to identify potential cases early and “stop further undetected spread of mpox.”
Meanwhile, Dr Simon Clarke, an infectious diseases expert at the University of Reading, told MailOnline: “It’s definitely possible it is spreading undetected.”
‘Whenever there are asymptomatic cases, there is always the possibility of a spread that we do not know about.
‘Unless there is systematic screening of everyone at the border, which there isn’t, then you will only know when people go to the NHS through the hospital or to their GP.
‘Inevitably, people have been traveling outside the region of Africa where it was, so it is very likely that it has spread across Europe.
“Cases have been detected in Germany and Sweden, so of course anyone who has been traveling there may also have been infected.”
Professor Paul Hunter, an infectious diseases expert at the University of East Anglia, said he was “surprised” that Britain’s first case of clade1b had not been detected sooner.
A woman cares for her baby who suffers from a severe form of mpox in eastern Democratic Republic of the Congo
The unnamed patient had returned to the UK after a holiday in Africa on an overnight flight on October 21.
“The fact that none have been reported does not necessarily mean that there have not been any.
“It is definitely plausible that there have been more infections in Europe than we are aware of.”
However, he cautioned: “I don’t think it’s as big a problem as what we saw two years ago.”
The clade 2 mpox strain spread around the world in 2022, primarily affecting gay and bisexual men.
But Professor Hunter said the new strain could “pose a big problem” if it started to spread among sex workers in the UK.
Mpox is not classified as a sexually transmitted infection, although it can be transmitted through direct contact during sexual intercourse.
Contagious lesions, through which infections are most likely to be transmitted, can appear anywhere on the body.
The infection can also be transmitted through contact with clothing or bedding used by an infected person.
Professor Hunter added: “Sex workers can have multiple partners, so if she had the strain she could infect quite a few men who use her services.”
‘Then they could pass it on to their own families.
“If we start to see a spread like that, then we will have to change our strategy.”
The clade 1b mutation, which experts have previously called “the most dangerous yet,” is believed to be behind a wave of miscarriages.
It has spread across central Africa killing at least 1,000 people since the outbreak began.
Countries such as the Democratic Republic of the Congo have been especially affected and cases have also been detected in Burundi, Rwanda, Uganda and Kenya.
Although designed for smallpox, Imvanex offers recipients cross-protection because the virus comes from the same orthopoxvirus family.
However, experts say Central Africa’s clade 1b mortality rates are unlikely to be replicated in developed countries such as the UK due to better access to higher quality healthcare.
Britain’s first case now means it joins countries such as Sweden, Thailand, India and Germany in having cases outside Africa.
He An unnamed patient had traveled back to the UK after a holiday in Africa on a red-eye flight on October 21.
They developed flu-like symptoms 24 hours later, followed by a rash, and went to the ER on October 27, where they were tested for mox.
Contacts of fewer than 10 people are currently being traced, although authorities are “still working” on the number of people they will need to monitor, the UKHSA said.
Currently, officials do not suspect that the patient was contagious on the return flight from the as-yet-unnamed African country where they contracted the disease.
UKHSA also said they are securing more supplies of mpox vaccines as part of the wider vaccine rollout.
The current mpox vaccines were used during the 2022 global outbreak against the milder strain.
It is a far cry from the 2022 outbreak, where thousands of cases were recorded, mainly in London.
Although designed for smallpox, Imvanex offers its recipients cross-protection because the virus comes from the same orthopoxvirus family.
The vaccine, believed to cost £20 per dose, contains a modified vaccinia virus, which is similar to both smallpox and mpox, but does not cause illness in people.
Experts warned today that despite the emergence of the new strain, Britain’s current targeted vaccination strategy “remains the best policy for the UK” and all “risk groups are covered”.
Dr Majeed told MailOnline: “The targeted vaccination program during the 2022 outbreak in the UK was effective in reducing the number of cases.
“For now, I believe that a targeted vaccination strategy remains the best policy for the UK.
“The targeted approach to vaccination aligns with patterns seen in previous outbreaks where most cases occurred in groups such as gay men.”
Common symptoms of mpox include a skin rash or pus-filled lesions that can last two to four weeks.
In a small number of cases, the infection can enter the blood and lungs, as well as other parts of the body such as the brain, making it life-threatening.
Anyone who has symptoms should continue to avoid contact with others as long as symptoms persist.
It can also cause fever, headaches, muscle aches, back pain, lack of energy, and swollen lymph nodes.