Monkeypox is a rare but serious viral infection. In recent years, monkeypox has increasingly emerged as a threat to humans, particularly in areas outside Africa.
Origin and transmission routes
Monkeypox is caused by the monkeypox virus (Monkeypox virus, Mpox virus), which belongs to the family of smallpox viruses. The virus was originally found in animals, particularly rodents and monkeys. Transmission to humans usually occurs through direct contact with infected animals or through the consumption of undercooked meat from infected animals. Transmission from person to person occurs primarily through direct skin and mucous membrane contact, as well as through contact with fluid from vesicles or lesions on the skin or mucous membrane of the infected person, especially during sexual contact.
The different variants of Mpox
There are two main variants of the Mpox virus, which can lead to different degrees of severity:
Central African tribe (Clade I)
This strain is more virulent and often leads to more severe courses of the disease. The mortality rate can be up to 10 %. It is assumed that this strain is also easier to transmit from person to person.
West African tribe (Clade II)
This strain is less virulent and generally causes milder courses of the disease. The mortality rate is around 1%, which is significantly lower than that of the Central African tribe.
International emergency due to Klade Ib
In August 2024, the WHO declared a global emergency due to Mpox because clade Ib is spreading rapidly in Africa. It is potentially more contagious and more dangerous than previously known variants. Clade Ib was discovered in the east of the Democratic Republic of the Congo at the end of 2023 and is spreading to other African countries.
The declaration of the highest alert level (“international health emergency”) serves as a warning signal for authorities worldwide to prepare for possible outbreaks and take appropriate measures.
Symptoms - How does monkeypox manifest itself?
The symptoms of monkeypox are similar to those of human smallpox, but are generally milder. They usually occur 5 to 21 days after infection. The disease often begins with non-specific symptoms such as fever, headache, muscle pain and fatigue. A rash develops within a few days, typically starting on the face and then spreading to other parts of the body.
The rash goes through several stages:
- First, flat, red spots appear on the skin
- after which the spots become fluid-filled blisters
- purulent pustules develop from this
- After some time, crusts form which fall off by themselves and the skin heals
- In the case of sexual transmission, the initial manifestation may be an ulcer at the site of entry and can easily be confused with other STIs such as syphilis.
The rash lasts around two to three weeks and can be very painful.
Diagnosis and treatment of monkeypox
Monkeypox is usually diagnosed by detecting the virus in skin lesions or by blood tests. Due to the rarity of the disease, it is important to visit a specialized medical facility if monkeypox is suspected in order to obtain an accurate diagnosis.
Treatment
There is currently no approved treatment for monkeypox. There are experimental trials with tecovirimat, the use of which can be considered in severe clinical courses. The therapy focuses on alleviating the symptoms and supporting the immune system. In severe cases, antiviral therapy may be considered. In addition, there are now vaccines that can offer a certain degree of protection. These vaccines are usually recommended for people who are at increased risk, such as healthcare workers or people who have close contact with infected people.
If you have been found to be infected with Mpox, be sure to follow the instructions of your treating doctor or the cantonal authorities to prevent the spread of the infection. It is recommended to isolate yourself until the crusts have fallen off.
“Smallpox vaccination is not recommended for the entire population, but only for certain risk groups, depending on the number of doses available.”
Prevention - How can travelers protect themselves?
We recommend that travelers to the affected areas of Africa avoid direct physical contact with other people if possible, especially if the other person has skin rashes or lesions.
The current situation has not changed the indication for vaccination, which remains as follows:
- Smallpox vaccination is not recommended for the entire population, but only for certain risk groups, depending on the number of doses available.
- Primarily as a post-exposure measure for people who have had unprotected contact with an infected person (e.g. family contact).
- Preventive for men and transgender people who have sexual intercourse with multiple male partners.
- As a preventive measure for people who are professionally exposed to the virus (medical staff or staff in special laboratories).
- For people who have had contact with infected persons, with the aim of breaking transmission chains and protecting people at risk.
Frequently asked questions
“Yes, sporadic clade II, and there was one case of clade I – a travel returnee who was quickly isolated,” explains Dr. Johannes Nemeth, senior physician at the Clinic for Infectious Diseases and Hospital Hygiene at the USZ.
Smallpox vaccination is not recommended for the entire population, but only for certain risk groups, depending on the number of doses available.
According to the Swiss Vaccination Plan 2025, Mpox vaccination is not planned for healthy children without risk factors.
If you are unsure whether your child belongs to a risk group (e.g. if your child has certain pre-existing conditions or has been in close contact with Mpox sufferers), it is best to speak to your pediatrician.
“The risk of Mpox clade I spreading worldwide is currently low, but cannot be ruled out,” says Dr. Johannes Nemeth. “So far, there have been no global outbreaks because most cases were quickly identified and contained.”
Individual cases outside Africa show that global spread is possible if no effective measures are taken. Good monitoring, rapid response to outbreaks and targeted vaccination measures in affected regions are therefore crucial to prevent further spread. If you think you may have Mpox yourself, seek medical advice as soon as possible and avoid close contact with other people or animals until the diagnosis has been confirmed.
Since the end of 2022, the World Health Organization (WHO) has recommended using the term “Mpox” instead of “monkeypox”. The background to this renaming is that the term “monkeypox” can be perceived as racist and stigmatizing, especially because it was associated with certain regions or population groups. The disease only got its original name because the virus was first discovered in monkeys in 1958 – but the actual natural hosts are rodents. The new name “Mpox” is intended to counteract stigmatization and promote neutral, objective communication about the infectious disease.
