The dating app is the world’s largest for men who have sex with men, who have been disproportionately infected in the unprecedented outbreak.
It issued the warning to its users across Europe last night, advising them to contact their sexual health provider if they or any recent sexual partners have unusual sores or rashes.
Monkeypox — usually only seen in west and central Africa — has now been spotted in 19 countries in little over a fortnight.
The tropical virus can spread through any close contact with a sick person, including by touching contaminated clothing, bedding or utensils.
Scientists believe the international outbreak could have been sparked by sex at two raves in Belgium and Spain.
The message from Grindr, which has partnered with health agencies in the UK and EU, sent users to the European Centre for Disease Prevention and Control’s page on monkeypox.
It also shared a linked to a webpage which enables users to find a local healthcare provider, in case they do not have their own doctor.
Monkeypox outbreak may have been sparked by sex at two raves in Belgium and Spain, WHO expert warns
Sexual transmission at two festivals in Europe may have sparked the world’s escalating monkeypox outbreak, a World Health Organization expert has claimed.
Dr David Heymann, who used to head the WHO’s emergencies department, revealed it was the leading theory behind the origins of the current cluster of cases.
He said: ‘We know monkeypox can spread when there is close contact with the lesions of someone who is infected, and it looks like sexual contact has now amplified that transmission.
‘It’s very possible there was somebody who got infected, developed lesions on the genitals, hands or somewhere else, and then spread it to others when there was sexual or close physical contact.
‘And then there were these international events that seeded the outbreak around the world, into the US and other European countries.’
Despite not naming either festival, health chiefs tasked with containing the virus have already begun tracing cases back to the Gran Canarian gay pride festival – attended by up to 80,000 people between May 5-15.
Meanwhile, three cases in Belgium have been linked with Darklands – a large-scale fetish festival in Antwerp, held from May 5-8. Organisers have since said there is ‘reason to assume’ someone at the event was infected.
Spanish health chiefs have also linked many cases to a single ‘sauna’ in Madrid.
The Grindr notification sent out said: ‘The monkeypox virus is spreading in Europe, particularly among men who have sex with men.
‘It is transmitted through close contact, like during sexual intercourse or through contaminated bedding, sex toys.
‘If you or any recent (last 21 days) partner have unusual sores or rash, contact your sexual health provider or local health provider.’
A Grindr spokesperson told MailOnline the message, issued in 13 languages, aimed to help users ‘understand the situation and find testing providers’.
The app is also working on a project with health chiefs in the US to communicate monkeypox public health advice to Americans.
The ECDC webpage advises that ‘men who have sex with other men that engage in casual sex, or who have multiple sexual partners’ should be vigilant.
It tells anyone with any tell-tale symptoms to seek specialist care and ‘abstain from sexual activities or any other type of activities involving close contact until monkeypox is either excluded or the infection is resolved’.
The disease, first discovered in lab monkeys in the late 1950s, is usually mild but can cause severe illness in some cases. It 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.
Monkeypox has an incubation period of anywhere up to 21 days, meaning it can take three weeks for symptoms to appear.
Symptoms include fever, headache, muscle aches, backache, swollen lymph nodes, chills and exhaustion.
A rash can develop, often beginning on the face, which then spreads to other parts of the body — including the genitals. The rash can look like chickenpox or syphilis, and scabs can form which then fall off.
Health chiefs tasked with containing the virus have already traced cases back to the Gran Canarian gay pride festival – attended by up to 80,000 people between May 5-15.
And three cases in Belgium have been linked with Darklands – a large-scale fetish festival in Antwerp, held from May 5-8. Organisers have since said there is ‘reason to assume’ someone at the event was infected.
It comes as the England today confirmed another 14 monkeypox cases, bringing the UK-wide total to 71.
England has logged 70 cases since the first case was publicised on May 7, while Scotland has recorded one. None have yet been detected in Wales or Northern Ireland.
Officials said a ‘notable proportion’ have occurred among gay and bisexual men but have not provided an exact breakdown. No gender or age details have been shared, either.
UKHSA teams are contacting people considered to be high-risk contacts of confirmed cases and advising them to self-isolate at home for three weeks and avoid contact with children.
They are also being offered the Imvanex vaccine, which was designed for smallpox.
Although not purposefully made for monkeypox, the jab — made by Danish-based Bavarian Nordic — is up to 85 per cent effective because the two viruses are so similar.
The strategy, known as ring vaccination, involves jabbing and monitoring anyone around an infected person to form a buffer of immune people to limit the spread of the disease. EU health chiefs yesterday called on member states to adopt a similar plan.
How DO you catch monkeypox and what are the symptoms? EVERYTHING you need to know about tropical virus
How do you catch monkeypox?
Until this worldwide outbreak, monkeypox was usually caught from infected animals in west and central Africa.
The tropical virus is thought to be spread by rodents, including rats, mice and even squirrels.
Humans can catch the illness — which comes from the same family as smallpox — if they’re bitten by infected animals, or touch their blood, bodily fluids, or scabs.
Consuming contaminated wild game or bush meat can also spread the virus.
The orthopoxvirus can enter the body through broken skin — even if it’s not visible, as well as the eyes, nose and mouth.
Despite being mainly spread by wild animals, it was known that monkeypox could be passed on between people.
However, health chiefs insist it is very rare.
Human-to-human spread can occur if someone touches clothing or bedding used by an infected person, or through direct contact with the virus’ tell-tale scabs.
The virus can also spread through coughs and sneezes.
In the ongoing surge in cases, experts think the virus is passing through skin-to-skin contact during sex — even though this exact mechanism has never been seen until now.
How deadly is it?
Monkeypox is usually mild, with most patients recovering within a few weeks without treatment.
Yet, the disease kills up to 10 per cent of cases. But this high rate is thought to be in part due to a historic lack of testing meaning that a tenth of known cases have died rather than a tenth of all infections.
However, with milder strains the fatality rate is closer to one in 100 — similar to when Covid first hit.
The UK cases all had the West African version of the virus, which is mild compared to the Central African strain.
It is thought that cases in Portugal and Spain also have the milder version, though tests are underway.
How is it tested for?
It can be difficult to diagnose monkeypox as it is often confused with other infections such as chickenpox.
Monkeypox is confirmed by a clinical assessment by a health professional and a test in the UK’s specialist lab – the UKHSA’s Rare and Imported Pathogens Laboratory.
The test involves taking samples from skin lesions, such as part of the scab, fluid from the lesions or pieces of dry crusts.
What are the symptoms?
It can take up to three weeks for monkeypox-infected patients to develop any of its tell-tale symptoms.
Early signs of the virus include a fever, headache, muscle aches, backache, swollen lymph nodes, chills and exhaustion — meaning it could, theoretically, be mistaken for other common illnesses.
But its most unusual feature is a rash that often begins on the face, then spreads to other parts of the body, commonly the hands and feet.
The rash changes and goes through different stages before finally forming a scab, which later falls off.
How long is someone contagious?
An individual is contagious from the point their rash appears until all the scabs have fallen off and there is intact skin underneath.
The scabs may also contain infectious virus material.
The infectious period is thought to last for three weeks but may vary between individuals.
What do I do if I have symptoms?
Anyone with an unusual rash or lesions on any part of their body, especially their genitalia, should contact NHS 111 or call a sexual health service.
Britons are asked to contact clinics ahead of their visit and avoid close contact with others until they have been seen by a medic.
Gay and bisexual men have been asked to be especially alert to the symptoms as most of the cases have been detected in men who have sex with men.
What even is monkeypox?
Monkeypox was first discovered when an outbreak of a pox-like disease occurred in monkeys kept for research in 1958.
The first human case was recorded in 1970 in the Democratic Republic of Congo and the infection has been reported in a number of central and western African countries since then.
Only a handful of cases have been reported outside of Africa and they were confined to people with travel links to the continent.
The UK, US, Israel and Singapore are the only countries which had detected the virus before May 2022.
Monkeypox is a rare viral infection which kills up to one in ten of those infected but does not spread easily between people. The tropical disease is endemic in parts of Africa and is known for its rare and unusual rashes, bumps and lesions (file photo)
Nurses and doctors are being advised to stay ‘alert’ to patients who present with a new rash or scabby lesions (like above)
Is it related to chickenpox?
Despite causing a similar rash, chickenpox is not related to monkeypox.
The infection, which usually strikes children, is caused by the varicella-zoster virus.
For comparison, monkeypox — like smallpox — is an orthopoxvirus. Because of this link, smallpox vaccines also provide protection against monkeypox.
Are young people more vulnerable?
Britons aged under 50 may be more susceptible to monkeypox, according to the World Health Organization.
This is because children in the UK were routinely offered the smallpox jab, which protects against monkeypox, until 1971.
The WHO also warns that the fatality rate has been higher among young children.
Does it spread as easily as Covid?
Leading experts insist we won’t be seeing Covid-style levels of transmission in the monkeypox outbreak.
A World Health Organization report last year suggested the natural R rate of the virus – the number of people each patient would infect if they lived normally while sick – is two.
This is lower than the original Wuhan variant of Covid and about a third of the R rate of the Indian ‘Delta’ strain.
But the real rate is likely much lower because ‘distinctive symptoms greatly aid in its early detection and containment,’ the team said, meaning it’s easy to spot cases and isolate them.
Covid is mainly spread through droplets an infected person releases whenever they breathe, speak, cough or sneeze.
How is the UK managing the outbreak?
MailOnline this week revealed close contacts of monkeypox cases, including NHS workers, are already being offered the Imvanex smallpox vaccine.
The strategy, known as ring vaccination, involves jabbing and monitoring anyone around an infected person to form a buffer of immune people to limit the spread of a disease.
A spokesman for the UKHSA did not disclose how many have been vaccinated, but said: ‘Those who have required the vaccine have been offered it.’
Health chiefs are also contacting all close contacts of those who have been infected.
Additionally, close contacts of those with a confirmed monkeypox infection are being told to stay at home for 21 days and avoid contact under-12s, immunosuppressed people and pregnant women.
The Government said unprotected direct contact or high risk environmental contact includes living in the same house as someone with monkeypox, having sexual contact with them or even just changing their bedding ‘without appropriate PPE’.
As with Covid, someone who has come within one metre of an infected person is classed as a monkeypox contact.
This lower category of contact, which also includes sitting next to a person with monkeypox on a plane, means a tracer will call the person every day for three weeks and they will be advised to stay off work for 21 days if their job involves children or immuno-suppressed colleagues.
The UK has stopped short of requiring people by law to quarantine if they develop monkeypox, but ministers are considering a public health campaign to alert gay and bisexual men, because of the number of cases in this group.
What if it continues to spread?
Experts told MailOnline they ‘could see a role’ for a targeted jab rollout to gay men in the UK ‘if this isn’t brought under control quickly’.
Close contacts of the UK’s known cases are already being offered the jab, which was originally designed for smallpox. The two rash-causing viruses are very similar.
A health source told MailOnline ‘there would be a number of strategies we’d look at’ if cases continued to rise.
Professor Kevin Fenton, London’s public health regional director, said if the outbreak in the capital continues to grow then the rollout of vaccines and treatments could be broadened to more groups.
He said there are ‘plans in place’ to have more antivirals if the outbreak keeps growing.
What other countries have spotted cases?
At least 16 countries — including the US, Spain and Italy — have now detected cases of monkeypox.
The World Health Organization (WHO) said it had been informed of 92 confirmed cases by Saturday and 28 suspected infections, most of which have been detected in Europe.
The most cases have been detected in Spain, Portugal, Canada and the UK.
Within Europe, France, Germany, Italy, Belgium, Austria, the Netherlands, Sweden and Switzerland have also confirmed cases.
Australia, Israel and the Canary Islands also have monkeypox patients, while health chiefs in Argentina are investigating a possible case.
The smallpox vaccine, called Imvanex in the UK and Jynneos in the US, can protect against monkeypox because the viruses causing the illnesses are related
Is there a vaccine for it?
The smallpox vaccine, called Imvanex in the UK and Jynneos in the US, can protect against monkeypox because the viruses behind the illnesses are closely related.
Data shows it prevents around 85 per cent of cases, and has been used ‘off-label’ in the UK since 2018.
The jab, thought to cost £20 per dose, contains a modified vaccinia virus, which is similar to both smallpox and monkeypox, but does not cause disease in people.
Because of its similarity to the pox viruses, antibodies produced against this virus offer cross protection.
Are there any drugs to treat it?
There are a handful of antivirals and therapies for smallpox that appear to work on monkeypox, including the drug tecovirimat, which was approved for monkeypox in the EU in January
There are a handful of antivirals and therapies for smallpox that appear to work on monkeypox.
This includes the drug tecovirimat, which was approved for monkeypox in the EU in January.
Tecovirimat prevents the virus from leaving an infected cell, hindering the spread of the virus within the body.
An injectable antiviral used to treat AIDS called cidofovir can be used to manage the infection, according to the US Centers for Disease Control and Prevention (CDC).
It also works by stopping the growth of the virus.
What is the situation with the UK outbreak?
Twenty cases were confirmed in the UK between May 6 and 20.
No details about the eleven confirmed on May 20 have been released yet.
But six of the previous nine confirmed cases were in men who have sex with men — which officials say is ‘highly suggestive of spread in sexual networks’.
How worrying is it?
UK health chiefs say the risk of a major outbreak is low.
But experts not that the outbreak is ‘concerning’ and that it is ‘very unusual’ to see community transmission in Europe.
Dr Michael Head, a global health expert at the University of Southampton, said the rise in cases is ‘undoubtedly worrying’.
But he noted that ‘a big monkeypox outbreak like this is still a very different situation to a Covid pandemic’.
Dr Head added: ‘Given 11 further cases have been announced today, it’s likely there will be more cases to come in the UK.
‘There certainly will be further cases confirmed in other countries. The contact tracing efforts by public health teams will be crucial in containing the outbreak.’
Dr Charlotte Hammer, an infectious diseases expert at the University of Cambridge, said: ‘It is very unusual to see community transmission in Europe, previous monkeypox cases have been in returning travellers with limited ongoing spread.
‘Based on the number of cases that were already discovered across Europe and the UK in the previous days, it is not unexpected that additional cases are now being and will be found, especially with the contact tracing that is now happening.’
What is the situation in the US?
The US has confirmed two cases and is investigating more.
A Massachusetts man on May 18 became the first confirmed US case for this outbreak.
On May 19, officials in New York City announced they were probing a suspected monkeypox case as well.
And what about Australia?
Australia last week confirmed its first every monkeypox infections.
One is a man in his thirties who travelled from Britain to Melbourne with symptoms earlier this week.
The second case is a man in his forties who became mildly unwell days after returning to New South Wales from Europe. Both he and the person he lives with are isolating at home.
What do I do if I have symptoms?
Anyone worried that they could be infected with monkeypox is advised to make contact with clinics ahead of their visit.
Health chiefs say their call or discussion will be treated sensitively and confidentially.