Frequently Asked Questions about Mpox

A new variant of the mpox virus has emerged in Africa, Clade Ib, which is more contagious compared to previous variants in the region. Compared to the variant that caused the outbreak in Europe and the rest of the world in 2022 (Clade IIb), the new variant might be a bit more aggressive. However, overall mortality with Clade Ib is relatively low (around 0,6% in the eastern part of the Democratic Republic of the Congo - DRC).

The World Health Organization (WHO) declared this outbreak a public health emergency of global concern. As of 24 December 2024, imported cases of the new variant have been reported in several countries outside of Africa, including one in Belgium. These were all isolated cases of travelers who contracted the disease in the affected countries in Africa, without sustained transmission.  The risk of infection for the general population remains very low.

There is no immediate cause for concern. Our researchers and medical specialists are closely monitoring and assessing the situation.

There is a vaccine on the market that offers protection against mpox (brand name Imvanex or Jynneos). This vaccine was originally developed against Variola virus (smallpox), but offers cross-protection against mpox. It is believed to be effective against both the West African and Central African variants. The vaccine is estimated to offer 80% protection. It is therefore still possible to contract the disease even after vaccination. After vaccination, the general preventive recommendations continue to apply.

Until the end of 2022, people belonging to a risk group could be vaccinated preventively against Clade II. We estimate that about half of those belonging to the risk group have been vaccinated. The Flemish government decided to end the preventive vaccination campaign against mpox in 2023. This means that it is no longer possible to get a vaccine against mpox. Health authorities are currently reviewing whether, with the advance of the Clade Ib variant, new vaccination campaigns are appropriate. The vaccine is currently not available to travellers to Africa.

Other vaccines, such as those against chickenpox (chickenpox) or zona, do not protect against mpox.

Mpox is a disease caused by the mpox virus. This virus is closely related to the virus that caused smallpox until the 1970s. There are two variants (or so-called clades) of the virus:

• Clade I (the Central African clade) primarily occurred in the rainforests of the Democratic Republic of the Congo (DRC). Until recently, infections were mainly due to animal-to-human transmission, mostly through contact with rodents. However, since late 2023, a subvariant of Clade I, known as Clade Ib, emerged in eastern Congo. Like Clade II, it is mainly transmitted from human to human, predominantly (but not exclusively) through sexual contact. Clade Ib has spread from Eastern DRC to neighboring countries of Uganda, Rwanda, Burundi and Kenia. Isolated import cases have been detected in several countries outside of Africa, including in Belgium, however, without indication of local transmission.

• Clade II (the West African clade) has been prevalent worldwide since the 2022 epidemic. It is primarily transmitted through sexual contact. It has caused a large number of cases, including in Europe. Although the epidemic subsided in 2022, new cases are sporadically detected in Europe and Belgium, without causing major outbreaks.

The Clade I outbreak has impacted major cities in the DRC, including Goma and Kinshasa, and is spreading to neighboring countries such as Burundi, Rwanda, Kenya, and Uganda. The risk remains low for most travellers, but it is strongly recommended to avoid:

• Skin-to-skin contact with individuals who are (or may be) infected

• Contact with bodily fluids, such as wound fluids

• Exposure to mucous membranes and saliva droplets

• Contact with contaminated surfaces or items, such as bedding or towels

• Consumption of wild animals

As for the Clade II variant, which caused the 2022 epidemic, there were about 80,000 confirmed infections worldwide, 789 of them in Belgium, by the end of November 2022. Since then, the outbreak has subsided. Sporadic new cases are still detected.

View the current epidemiological situation:

• Europees Centrum voor ziektepreventie en -bestrijding

• Sciensano

• World Health Organization

Since mpox virus is closely related to smallpox virus, the old smallpox vaccine also provides protection against mpox. Routine vaccination against smallpox was discontinued in Belgium in the 1970s. It is possible that vaccination in childhood still offers some protection against mpox. However, vaccine protection decreases with age. It is therefore still possible to become infected. Preventive measures still apply.

Often, flu-like syndromes (fever, muscle aches, headache, general unwellness) develop 5 to 21 days after infection, followed by skin lesions.

These skin lesions may be (red) patches, pimples, vesicles or suppuration, which finally heal after scabs form. Skin lesions can occur anywhere on the body and are sometimes painful. They are often seen at the site of infection, especially around the anus, on the genitals or in the mouth. The lesions are often accompanied by substantially swollen and sometimes painful glands. These skin lesions can occur even without fever or flu syndrome.

Sometimes we also see less classic presentations, for example people with few or no skin lesions or only localised symptoms, such as inflammation of the throat, anus or urethra.

You can contract mpox through:

• Direct contact (prolonged skin-to-skin or sexual) with someone with skin lesions (the skin lesions contain a lot of virus).

• Contact with body fluids or mucous membranes of an infected person. In infected patients, we often find high concentrations of virus in saliva and anus, but sometimes also in semen.

• Spread from saliva droplets. This is possible, but probably less efficient.

• (In theory) transmission through contaminated surfaces or linen (such as bedding or towels).

The virus spreads most efficiently through sexual contact. Kissing can also potentially pose a risk. People who have multiple sexual partners are more at risk of contracting the disease.

The doctor may suspect an infection with mpox based on the symptoms. If it is suspected, a sample is taken. This involves taking several swabs from, for example, the skin lesions, throat, anus, or saliva. The presence of the virus is determined via a PCR test. It takes at least 24 hours before the results are known.

The samples should be taken in protected conditions (with protective clothing for the care worker and in a separate room) to avoid spread.

You may be infected with mpox if you:

• have unexplained ‘smallpox-like’ skin lesions, either around the anus, mouth and/or genitals, or all over the body and you:

  • are either a man who had intimate contact with one or more men in the last few weeks;

  • either have been in West or Central Africa and had close contact (sexual or otherwise) with the local population;

• had close contact in the last three weeks with someone infected with mpox virus and you either:

  • develop fever or flu-like symptoms;

  • develop skin lesions;

  • have symptoms of possible inflammation of the throat, anus or urethra.

If you suspect you have mpox, you should contact a centre where you can be tested as soon as possible. To avoid infecting other people, you should isolate yourself at home as much as possible.

The ITM policlinic can be reached by phone on weekdays from 9am to 5pm at +32 (0)3 247 66 66. If you live outside Antwerp, you can contact the emergency department of a hospital with an infectious diseases specialist on site (travel-clinics / yellow-fever-vaccination-centres).

Always contact health care providers before visiting the clinic. This will allow the health staff to prepare and closely monitor the very strict protective measures. If in doubt, you can always contact your GP by phone, but before your consultation, be sure to let them know that you suspect you are infected with the mpox virus.

• Avoid contact with (potentially) infected people until they are allowed out of isolation.

• Limit your sexual contacts and discuss mpox with your partner. Anonymous sexual contacts are risky and make it difficult to notify exposed partners in time.

• Travellers to countries where mpox is prevalent are best to keep their distance from people with obvious skin lesions.

• In affected countries in West Africa and Central Africa, sex for payment is strongly discouraged.

• Vaccination is a good way to prevent mpox infection, but does not fully protect. In fact, cases of post-vaccination mpox infections have been reported. Exact data on the degree of individual protection after vaccination are not yet available.

General measures remain necessary:

• Modification of risk behaviour

• Isolation in case of complaints

• Avoidance of sexual contact and skin-to-skin contact with sick persons

In most cases, the disease heals spontaneously after a few weeks with no residual symptoms.

Sometimes scars remain. A small minority of patients require hospitalisation during the acute infection, usually for pain control. Sometimes complications occur, such as severe inflammation of the skin lesions or the anus.

Fortunately, the disease is very rarely fatal. The few people who died from the virus in Europe usually had other serious underlying conditions (mainly immune system problems).

The Central African variant is possibly more aggressive. In Africa, it is mostly very young (and sometimes malnourished) children who die from the virus. This is often because they do not have sufficient access to proper health care.

No specific treatment is currently available. In case of symptoms, supportive treatment includes painkillers, antipyretics, anti-itch drugs and so on

Tecovirimat is the most promising antiviral drug. However, a recent study shows that in Congo, the drug has little impact on disease progression. This medication is therefore currently used for research purposes only.

In Belgium, very severe cases with a complicated form of mpox can receive treatment with tecovirimat. These are usually patients with some form of immune deficiency, such as leukaemia, or patients taking medication that acts on the immune system. The Belgian government provides a limited number of treatments for this purpose.

A clinical trial with tecovirimat is currently running at ITM. Adults with mpox who wish to do so can take part in it and receive tablets containing either the antiviral drug or a placebo.

Go into isolation at home until all skin lesions have dried up. This way, you avoid infecting other people. This includes:

• Staying at home. Leave the house only for essential matters such as doctor's appointments. Let someone else do your shopping. Wear a surgical mouth mask and cover skin lesions (by wearing long sleeves and long trousers, for example) when you go outside.

• Staying in your room. Wear a surgical mask if you leave your room and/or have contact with housemates.

• Using your own household items such as clothes, bedding, towels and eating utensils. Never share them with other housemates.

• Avoiding physical (sexual) contact until the skin lesions have healed (when the scabs have fallen off). Condoms alone do not provide complete protection against mpox.

• Avoiding contact with animals, especially rodents such as mice, rats, hamsters and guinea pigs.

• Notifying anyone you have had close contact with in the last three weeks. This way, they can monitor their own symptoms and act appropriately if symptoms occur.

• Extensive medical information - Centers for Disease Control CDC (EN)

• Factsheet - World Health Organization WHO (EN)

• Medical information for the general public - RIVM (NL)

• Information on the evolution of the mpox epidemic in Europe (number of cases per country) - ECDC (EN)

• Mpox - Agency for Care and Health (NL)

• Green line 1700 (call centre) - Agentschap Zorg Vlaanderen (NL)

We expect that during an active mpox infection, high concentrations of the virus are present on all mucous membranes (mouth, anus, urethra) and on the skin for several weeks. Any kind of contact with these mucous membranes (anal, oral, vaginal) and skin can cause transmission. We see that most people contract monkeypox through sexual contact. We recommend not being sexually active (insertive oral, anal, vaginal) for at least 21 days or until all skin lesions have healed. Kissing, tongue kissing and intense nude cuddling are also considered risk contacts.

A monogamous sexual relationship or masturbation do not pose a risk.

The risk depends on the type of contact you had with the infected person. There is a distinction between very high-risk, high-risk and low-risk. In practice, we mostly see infections after a very high-risk contact.

Very high-risk contacts are:

• sexual contacts;

• prolonged skin-to-skin contact while the infected person had a rash.

High-risk contacts are:

• living in the same household or environment as the infected person;

• sharing clothing, bedding or kitchen utensils while the infected person had a skin rash;

• caring for an infected person with symptoms;

• contact with an infected person during (para)medical care without appropriate personal protective equipment;

• a sharp injury or exposure (without personal protective equipment) to body fluids of an infected person or to aerosols generated during a (medical) procedure;

• exposure to a contaminated sample during laboratory procedures, without personal protective equipment;

• sitting for three hours or more close to (one or two seats) a symptomatically infected person (on a plane, bus or train).

Like vaccination, a previous infection presumably provides protection against a new infection. However, like the vaccine, this protection is not 100%. It is therefore possible to contract the disease twice.  After a previous infection, the general preventive recommendations continue to apply.