According to health experts, another 18 cases of monkeypox have been reported in the United Kingdom.
Over the previous 24 hours, 11 instances have been discovered in England, according to the UK Health Security Agency (UKHSA).
There were no new cases discovered in Scotland, Wales, or Northern Ireland, bringing the total number of cases in the UK to 190.
Officials said the ‘risk to the general population from monkeypox is still low,’ but advised that if people become symptomatic, they must take efforts to reduce transmission.
Anyone who develops a new rash or blister should isolate and phone 111, according to UKHSA officials, and should not leave isolation ‘until you’ve been informed what to do.’
Until now, those with suspected or confirmed cases of monkeypox were being urged to seek advice from a GP.
But officials said the move to introduce quarantine was to prevent further spread ‘now that community transmission is occurring here in the UK and other countries’.
People with new lesions are being advised to stay at home as long as they remain well enough.
They are also been ordered to abstain from sex or close contact with others ‘until their lesions have healed and the scabs have dried off’.
Those who test positive for the infection are being urged to wear a condom for at least eight weeks after clearing the virus. The guidance is purely advisory and is not enforceable by law.
Dr Ruth Milton, senior medical advisor at UKHSA, said: ‘The risk to the general public from monkeypox is still low, but it’s important that we work to limit the virus being passed on.
‘We remind people that they should be alert to new spots, ulcers or blisters on any part of their body.
‘If anyone suspects they might have these, particularly if they have recently had a new sexual partner, they should limit their contact with others and contact NHS 111 or their local sexual health service as soon as possible, though please phone ahead before attending in person.’
Almost all of the UK monkeypox infections have been logged in England, apart from four logged in Scotland, two in Northern Ireland and one in Wales.
UK health chiefs insist the risk to the public remains low.
But they have urged everyone to be on the lookout for new rashes or lesions on any part of their body — which appear like spots, ulcers or blisters.
The UKHSA has not shared the age, region or gender of those infected with monkeypox.
The majority of cases have been in gay men, who have been told to be particularly aware of the virus’s tell-tale signs.
So far the outbreak, which was first detected in early May, has spread to 24 countries, with the UK, Spain and Portugal logging the most infections.
The World Health Organization yesterday upgraded the threat from the virus to ‘moderate’.
It said the explosion of cases with no links to each other or Africa means the current figure is ‘likely to be an underestimate’.
Writing in the guidance published on Monday, the UKHSA said: ‘People with possible, probable or confirmed monkeypox should avoid contact with other people until their lesions have healed and the scabs have dried off.
‘Do not go to a sexual health clinic without contacting them first. Stay at home and avoid close contact with other people until you’ve been told what to do.’
Teams from the UKHSA are contacting high-risk contacts of confirmed cases and advising them to self-isolate at home for three weeks and avoid contact with children.
Both confirmed cases and close contacts are being offered the Imvanex vaccine to form a buffer of immune people around a confirmed case to limit the spread of the disease.
The strategy, known as ring vaccination, has been used in previous monkeypox outbreaks and is also being carried out in some EU countries.
Dr Milton said: ‘We are continuing to work closely with our colleagues in Scotland, Wales and Northern Ireland to ensure we are aligned in our approach to reducing the risk of transmission of monkeypox in the UK.’
It comes after the WHO published a risk assessment on Sunday, warning that its ‘moderate’ grading of the outbreak could be pushed to ‘high’ if the virus ‘exploits the opportunity to establish itself as a human pathogen’ and spreads to vulnerable groups.
The ‘sudden appearance’ and ‘wide geographic scope’ of cases suggests widespread human transmission of the virus — which spreads through skin-to-skin contact and an infected persons’ droplets — is underway, the WHO said.
It also warned the surge in monkeypox infections suggests the virus ‘may have been circulating unrecognised for several weeks or longer’.
Reported cases have so far been mild but there is a risk the virus has a ‘greater health impact’ if it spreads to at-risk people, including children and immunocompromised people, such as some HIV patients, who ‘may be especially at risk of more severe disease’.
Monkeypox can kill up to 10 per cent of people it infects. The milder strain causing the current outbreak kills one in 100 — similar to when Covid first hit. The virus death rate has been higher among children in previous outbreaks.
The WHO warned there is a ‘high risk’ of further spread of the virus though skin-to-skin contact between families and sexual partners, as well as due to contact with contaminated materials, such as utensils, bedding and clothing.
‘However, at present, the risk for the general public appears to be low,’ the agency said.
It cautioned that a ‘large part’ of the population is vulnerable to monkeypox due to the discontinuation of the smallpox vaccination scheme.
Very few people under the age of forty have been vaccinated. In the UK, youngsters were routinely offered this jab until four decades ago, around the point at which the virus was eradicated.
Because smallpox and monkeypox are so similar, those who received the jab are thought to have up to 85 per cent immunity against the circulating strain.
There is a ‘potential risk’ to health workers who treat someone infected with the virus if they are not wearing personal protective equipment (PPE) to prevent transmission, the WHO siad.
No monkeypox cases have been confirmed among medics in the current outbreak, it noted, but an NHS worker became infected in 2018 after treating a patient who had returned from Nigeria.
In its report, the WHO also warned that people who have recently had multiple sexual partners — either where they live or abroad — ‘may be at risk’ of having monkeypox.
It said health chiefs should reach out to at risk communities, which ‘at the present time’ includes men who have sex with men and their close contacts.
The WHO said it ‘would be prudent’ for people to limit the number of sexual partners they have during the early stage of this outbreak.
It comes as Dr Will Nutland, from the London School of Hygiene and Tropical Medicine, warned that festivals could fuel the spread of the virus.
The current outbreak, first detected in a traveller from Nigeria to the UK on May 6, has been linked to several super-spreader events, including a gay pride festival in Gran Canaria, a fetish festival in Belgium and a ‘sauna’ in Spain.
Dr Nutland hosted a webinar for the LGBTQ+ community about the risks of monkeypox, as part of his roles as co-founder of Prepster, a volunteer group of HIV prevention activists in London.
The doctor warned that it could spread at the Mighty Hoopla in Brockwell Park, south London, this Friday and Saturday.
He told the Sunday Telegraph that the pop festival is ‘going to attract a lot of queer people’.
A spokesperson for the Mighty Hoopla said that they ‘remain committed to working in line with government health guidance regarding public safety at events’.
Earlier this month, Dr Hans Kluge, regional director for Europe at the World Health Organisation, said he is concerned about ‘mass gatherings, festivals and parties’, which could accelerate transmissions.
He said that the cases being identified are ‘among those engaging in sexual activity’, and creates unfamiliar symptoms.
Mateo Prochazka, epidemiologist from the UK Health Security Agency (UKHSA), said that it is important people do not assume monkeypox is only a threat to the LGBTQ+ community
He told the BBC that it can spread to anyone through close contact — including contact with items used by someone infected, such as cutlery or their clothes