Mpox
The mpox virus (formerly known as monkeypox) is transmitted mainly through close contact, especially sexual contact. The disease is generally mild. A vaccine is available.
Virus and transmission
The mpox virus belongs to the orthopoxvirus genus. It is divided into two distinct clades: clade I and clade II.
Human-to-human transmission occurs mainly through direct contact with the skin and mucous membranes and through contact with infected secretions from blisters or lesions on the skin or mucous membranes, particularly during sexual contact.
The virus can also be transmitted through scabs, respiratory secretions and bodily fluids. During pregnancy, it can be transmitted to the foetus via the placenta. It is currently uncertain whether it can spread through semen, vaginal secretions, urine or faeces.
Clinical presentation
The first symptoms generally appear 5 to 13 days after close contact with an infected person, although the incubation period can range from 1 to 21 days. The severity of symptoms varies from person to person.
In some cases, only a few mild symptoms occur. The skin rash is often subtle, with only a few or isolated blisters or pustules. The blisters or pustules (lesions) may be painful or itchy and can appear at different stages. The disease may also cause flu-like symptoms (fever, chills, headache, sore throat, muscle and back pain, etc.) or symptoms in the genital and anal area (pain, bleeding, inflammation).
An infected person is probably contagious from the onset of the first symptoms until the skin rash has cleared, i.e. until the last scabs have fallen off.
The disease generally resolves on its own without serious long-term consequences. Immunocompromised people, infants, children and pregnant women appear to be at greater risk of severe disease.
Treatment primarily focuses on relieving the symptoms.
Spread and frequency
The natural reservoir of the mpox virus has not yet been established. In the affected regions of Africa, various small mammals, particularly certain rodent species, can become infected and transmit the virus to humans. Since the first human case was identified in 1970, cases have regularly been observed in several countries in Central and West Africa, sometimes sporadically and sometimes in larger numbers. Before 2022, cases outside Africa were rare and were mainly linked to travel or the importation of infected animals. An outbreak linked to imported animals occurred in the United States in 2003.
From summer 2022, a global mpox outbreak caused by clade IIb also affected Switzerland. Initially observed only in Africa, clade Ib was detected outside the continent from 2024, including in Europe. It was first identified in Switzerland in 2025.
Since autumn 2022, the number of reported cases across all clades has fallen markedly in Switzerland and the rest of Europe. Sporadic cases and occasional temporary increases in case numbers nevertheless continue to occur. In Switzerland and elsewhere in Europe, mpox mainly affects, but is not limited to, men who have sex with men (MSM) and trans people who have male sexual partners, particularly those who frequently change partners. The risk to the general population is low.
Prevention
People at increased risk of infection can generally protect themselves from transmission by adapting their behaviour. This includes avoiding contact with infected people.
The Jynneos® vaccine from Bavarian Nordic can also be administered preventively. Based on current knowledge, the available vaccine is effective against the mpox virus clades present in Switzerland (clade I and clade II) and is considered safe. People who have received a complete mpox vaccination or have previously had a clade II mpox infection are also likely to be protected against mpox caused by clade I. Breakthrough infections are nevertheless possible.
Vaccination is recommended for people at risk of occupational exposure to the virus (e.g. laboratory personnel), as well as for MSM and trans people who frequently change sexual partners.
Following risk contact with a confirmed or probable mpox case, vaccination is recommended as post-exposure prophylaxis. It should be administered within four days of exposure, but no later than 14 days afterwards.
If the risk of exposure persists, a single booster dose is recommended no earlier than two years after completion of the primary vaccination series.
Anyone wishing to be vaccinated can find further information at www.impfen-schweiz.ch and should first seek advice from a specialist physician.
The cantons are responsible for organising and administering the vaccination and determine where it is available. Information on vaccination options and specialist physicians is available from the cantonal health authorities.
Information on the coverage of vaccination and vaccine costs by compulsory health insurance (basic insurance) is available on the FOPH webpage Coverage of vaccination costs. The factsheet on financing mpox vaccination also provides further information on access to the vaccine, requirements for service providers and the billing process.
And for everyone who is sexually active:
“Take the Safer Sex Check at www.lovelife.ch.”
Recommendations when travelling to Africa
The mpox virus can be contracted through contact with animals carrying the virus, particularly rodents, or through contact with infected people.
If preventive measures are followed (e.g. avoiding contact with wild animals and potentially infected people), the risk of contracting the virus while staying in areas affected by the current outbreak remains very low. Close physical contact, especially sexual contact, nevertheless greatly increases the risk. It is therefore advisable to avoid such situations as far as possible.
The Swiss Expert Committee for Travel Medicine (ECTM) has compiled further information and specific guidance, available at www.healthytravel.ch (search term “mpox”). In particular, staff of aid organisations who may be exposed to the virus during humanitarian missions in risk areas are advised to be vaccinated in accordance with the current recommendations.
Compulsory health insurance does not generally reimburse vaccinations for travel abroad. If vaccination is indicated for occupational reasons, the employer covers the costs.
Further information is also available at:
Home | Swiss AIDS Federation
Home | Dr. Gay - English (drgay.ch)
www.healthytravel.ch > keyword ‘mpox’
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Federal Office of Public Health FOPH
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Switzerland - 3003 Bern