Frequently Asked Questions about Mpox

Since 2024, two variants of mpox have been circulating, with the more recent Clade Ib likely being somewhat more transmissible and aggressive than the longer-circulating Clade IIb. However, the mortality rate of Clade Ib remains very low.

From 2023 to 2025, only a limited number of mpox cases were observed in Belgium, but since the beginning of 2026, the number has been increasing again. The reasons for this are not yet fully understood, but it may be linked to reduced awareness of the disease, the higher transmissibility of Clade Ib mpox, and a possible decline in protection from the mpox vaccine over time.

A vaccine is available on the market that offers protection against mpox (brand name Imvanex or Jynneos). This vaccine was originally developed against the variola virus (smallpox), but it also provides cross-protection against mpox. The vaccine is estimated to offer up to 80% protection. This means that it is still possible to contract the disease after vaccination. General preventive recommendations therefore continue to apply after vaccination.

Until the end of 2022, people belonging to a risk group for mpox could receive preventive vaccination. We estimate that approximately half of the people in the risk group were vaccinated at that time. In 2023, the Flemish government decided to stop the preventive mpox vaccination campaign. This means that it is currently no longer possible to receive an mpox vaccine.

Other vaccines, such as those against chickenpox or shingles, 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, both of which are now circulating worldwide.

• Clade I occurred mainly in the Democratic Republic of the Congo (DRC) before 2024. At the end of 2023, a new variant, Clade Ib, emerged in eastern Congo. It is transmitted mainly (but not exclusively) through sexual contact and is now found worldwide.

• Clade II has been circulating worldwide since the 2022 epidemic and is mainly transmitted through sexual contact. This variant has led to approximately 80,000 confirmed infections, including 789 in Belgium. Although the epidemic declined sharply after 2022, the virus continued to circulate globally and caused sporadic cases.

View the current epidemiological situation:

• European Centre for Disease Prevention and Control

• 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 develop unexplained skin lesions around the anus and/or genital area and you are a man who has had intimate contact with one or more other men in recent weeks;

• you have 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.

• 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.

Other general measures remain necessary:

• Isolation in case of complaints

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

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).

Symptoms are treated supportively with, among other things, painkillers, fever-reducing medication, anti-itch medication, and similar treatments.

Tecovirimat was considered a promising antiviral drug. However, recent studies have shown that the drug has no impact on the course of the disease. For this reason, this medication is currently no longer used outside experimental studies.

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 for several weeks on all mucous membranes (mouth, anus, urethra) and on the skin. Any contact with these mucous membranes (anal, oral, vaginal) and with the skin can cause transmission. We see that most people contract mpox through sexual contact. We recommend avoiding sexual activity (insertive oral, anal, or vaginal sex) for at least 21 days, or until the skin lesions have healed. Kissing, tongue kissing, and intensive naked cuddling are considered risk contacts.

A monogamous sexual relationship or masturbation does not pose any risks.

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.