FAQ MPOX

Mpox, formerly known as monkeypox or orthopoxvirosis simiana, is an infectious disease caused by the monkeypox virus, a virus similar to that of smallpox. This disease is a zoonosis, meaning that the virus circulates in an animal reservoir (small mammals), and is sometimes transmitted to humans. It is endemic in West and Central Africa, where cases, and sometimes epidemics, are regularly reported. In these regions, the number of cases has risen sharply over the last 5 years, and particularly since 2023.

In 2022, in a highly unusual development, a large-scale global epidemic affected mainly men who declared that they had sex with men. This situation led to the first declaration of a public health emergency of international concern (USPPI) by the WHO in July 2022. The epidemic was brought under control by vaccination and public health measures, and the USPPI ended in May 2023.

Since 14 August 2024, a new PHEIC has been declared by the WHO due to an increase in the number of cases reported in the Democratic Republic of Congo, and the identification of a new variant (clade) of the virus in the east of the country and neighbouring countries. There are still uncertainties surrounding the transmissibility and mortality of this new variant, which is currently under investigation.

In the majority of cases, the disease causes lesions that heal on their own after a few weeks. However, some people suffer severe localised pain or more severe forms (encephalitis, myocarditis), and the virus has even caused deaths. Newborns, children and people with underlying immune deficiencies are at risk of more severe symptoms and death. even in healthy young people. During the 2022 global epidemic, around 10% of those diagnosed required hospitalisation.

People with mpox are infectious for as long as they have symptoms (generally two to four weeks). People contract mpox through close physical contact with someone showing symptoms. Skin rashes, body fluids (such as fluid, pus or blood from skin lesions) and scabs are particularly infectious. Clothing, bedding, towels or objects, such as kitchen utensils or crockery, that have been contaminated by the virus through contact with an infected person can also infect other people. 
Mouth ulcers, lesions or sores can also be infectious, meaning that the virus can be transmitted via saliva. People who interact closely with an infected person, such as family members and sexual partners, are therefore at increased risk of infection. 
The virus can also be transmitted from a pregnant person to the foetus via the placenta, or from an infected parent to their child during or after birth via skin contact. Healthcare workers are at increased risk of infection if they care for sick people without the appropriate protective equipment. 

The virus responsible for monkeypox is mainly transmitted by direct contact with a lesion, whether cutaneous, genital or anal. Transmission can therefore occur during sexual intercourse, which involves direct and prolonged contact. More rarely, it can also occur through indirect contact with contaminated objects, linen or sheets, or through prolonged contact with respiratory secretions (sputum).

According to current information from the European Centre for Disease Prevention and Control (ECDC) and the modes of transmission described above, the risk of acquiring monkeypox contagion is very low in the general population, but high in men - people with several sexual partners, including men who have sex with men - and in the household of a symptomatic person. In-depth scientific analysis of transmission routes is currently underway.
A person may be contagious before the appearance of skin lesions, as soon as the first flu-like symptoms appear.

Mpox usually begins with a fever, sometimes accompanied by flu-like symptoms (headache, sore throat, muscle aches, backache, swollen lymph nodes, chills, exhaustion). It rapidly develops into a skin rash with fluid-filled lesions, which gradually form scabs. These lesions can appear on the face, palms and soles of the feet, or on other parts of the body, including the genitals. In around a third of cases, the lesions may be located only on the genitals or around the anus. They may also appear in the mouth and eyes.  Symptoms last from two to four weeks and generally disappear spontaneously. 

The incubation period is usually around a week, but can be as long as 21 days. The period of infectivity is not yet definitively known. It begins with the appearance of symptoms and decreases sharply once the rash has disappeared and a new layer of skin has formed. The duration of virus persistence in sperm is currently being studied.

Contact a doctor, who will decide whether or not you need to undergo screening for the virus.

A doctor takes a smear from the lesions or from the throat. The sample is then sent to the Centre de référence des infections virales émergentes (CRIVE), which has a PCR test (a laboratory technique that consists of amplifying part of the genetic material of a virus to identify it) to diagnose monkeypox.

You should limit your contacts and follow the advice of the Cantonal Health Office until you are no longer contagious, i.e. as soon as the scabs have fallen off and a new layer of skin has formed underneath. The Cantonal Medical Service will contact you to discuss the individual measures to be taken according to your lesions to prevent secondary transmission, and to draw up a list of the people with whom you have been in contact. The Confederation recommends that the cantons activate contact tracing for confirmed cases.

Most infections heal spontaneously. There is therefore generally no need for specific treatment. Medication for fever and pain can be given if necessary. In particularly serious cases, or where there is a risk of seriousness, an antiviral treatment known as tecovirimat may be administered at the HUG, either as part of a research study known as UNITY, or as part of exceptional access authorised by the Swiss Federal Office of Public Health.

The World Health Organization recommends vaccinating people at high risk, whether in the private or professional sphere (e.g. health and laboratory personnel). In Switzerland, vaccination recommendations concern people at risk of sexual or professional exposure, such as people traveling to endemic or epidemic areas to work or carry out a mission in an mpox care center, or working with the Mmpox reservoir.

According to the recommendations, the following people can be vaccinated:

• As a preventive measure, people over 18 years of age with a dense sexual network, such as men who have sex with men and transgender people who frequently change sexual partners;
• As a preventive measure, people over 18 years of age exposed to the virus in a professional setting (e.g. medical or specialist laboratory staff);
• People who have had contact with people who have contracted the disease (vaccination should be done within 4 days of contact, but up to 14 days after contact at the most);
• People who have received two doses of Jynneos® approximately 20 to 24 months ago, a booster injection is recommended as long as the risk of exposure persists;
• For people who have already been vaccinated against human smallpox in childhood (scar on the arm), a single injection is recommended. It is established that the vaccine used before 1980 induces an immune response against all orthopoxviruses and can protect against mpox. However, the persistence of an antibody titer sufficient to protect against infection, beyond 20 years after the primary vaccination, is not guaranteed. Thus, a single dose of vaccine is recommended.

Who is potentially not eligible to be vaccinated:

• People who have received two doses of the mpox vaccine abroad;
• People who have already been infected with mpox. Indeed, vaccination is currently not recommended for people who have recently contracted mpox. Due to contracting the disease, the immune system has already been exposed to the virus and is now ready to recognize it.
• People under 18 years of age and pregnant women should discuss this with their doctor to make a careful assessment of the benefit-risk ratio;
• People who have had a serious allergic reaction (anaphylactic shock) to a previous dose or to a component of the Jynneos® vaccine. Jynneos® contains a modified Vaccinia Virus Ankara - Bavarian Nordic virus (active substance), tromethamine, sodium chloride and, in small amounts, benzonase, gentamicin, ciprofloxacin (antibiotic), chicken host cell DNA and chicken proteins;
• People suffering from an acute illness with fever (from 38.5oC) should postpone vaccination. It remains possible in case of chill and slight rise in temperature (less than 38.5oC).

For the moment, no vaccination recommendations are planned for other groups of the population.

Vaccination is also recommended in the event of a risky contact, as post-exposure prophylaxis.

Vaccination locations:

For people with a dense sexual network, such as men who have sex with men and transgender people who have male sexual partners and change them regularly or for people at risk of sexual exposure in endemic or epidemic areas.

• Unité VIH
  Service des maladies infectieuses
  Bâtiment Morier, 2e étage 
  Hôpitaux universitaires de Genève
  Rue Gabrielle-Perret-Gentil 6
  1205 Genève
  Tel. : 022 372 96 17
  Mail : infectiologie.ambulatoire@hcuge.ch

• Checkpoint Genève
  Rue du Grand-Pré 9 
  1202 Genève 
  Tel. : 022 906 40 30
  Mail : vaccination.mkp@dialogai.org et/ousecretariat.checkpoint@dialogai.org
  Site : Checkpoint Genève
   
• Groupe santé Genève
  Rue du Grand-Pré 9
  1202 Genève
  Tel : 022 700 15 00
  Site : https://groupesantegeneve.ch

For people at risk in their professional environment and those traveling to a high-risk region or with potential sexual promiscuity:

• Service de médecine tropicale et humanitaire
  Hôpitaux universitaires de Genève
  Bâtiment Morier, 3e étage
  Rue Gabrielle-Perret-Gentil 6
  1205 Genève
  Tel. : 022 372 96 15
  Mail : info.medint@hug.ch

Vaccination provides protection against severe disease (see tab "Can you get vaccinated against smallpox?").

In addition, there is cross-immunity with smallpox. Thus, people who received the smallpox vaccine during their childhood (who are now over 50 years old, because vaccination was stopped in Switzerland in 1972) could benefit from residual protection. People previously vaccinated against smallpox would have a lower risk (about 5x less) of developing smallpox.

Mpox is not transmitted like COVID-19. Transmission requires close and prolonged physical contact with an infectious person (e.g. skin-to-skin contact) to pass from person to person. The risk to the general public is low.

Today, the virus circulates mainly among people who have multiple sexual relationships, and in some sub-Saharan African countries in endemic foci due to introductions from the natural environment (animals). However, anyone, regardless of sexual orientation, gender or age, can contract the disease if they engage in activities that risk exposure.

As long as the virus is transmitted, it continues to adapt: ​​it will evolve and mutate like any new virus in humans. We cannot rule out that one day there will be a more widespread transmission. It is therefore necessary to take all possible measures to limit the circulation of this virus. Similarly, determining how the virus spreads and protecting more people from infection are priorities.