What is mpox?
Mpox, also known as monkeypox, is a viral infection that originally occurred mainly in West and Central Africa. Sometimes a traveller from that region will carry the disease to Europe. It is a zoonosis (a disease that can be transmitted from animals to humans) that mainly comes from rodents in Africa. The course of illness is usually mild in humans, but can cause great pain and leave permanent scars. The word ‘monkeypox’ is often used for impetigo on the islands of Aruba, Bonaire and Curaçao and in Suriname.
After a spike in the summer of 2022, the number of reported cases declined sharply in the fall of 2022.
Symptoms of mpox
The symptoms of an infection with the mpox virus are similar to smallpox, but mpox generally causes a much milder course of illness. The most important symptom is the skin rash, which can present as red spots, bumps or lesions. These bumps or lesions eventually form the blisters, which can be painful. The blisters dry up and form a crust, leaving scabs that eventually fall off two to three weeks later. The blisters may leave scars.
Other general symptoms that are associated with mpox include:
- muscle ache
- swollen lymph nodes
Some cases of mpox start with general symptoms followed by the skin rash, while others start with the rash and then develop other symptoms. A number of people in the current outbreak have also had proctitis, a painful inflammation of the lining of the rectum (the final part of the intestines). Sometimes proctitis is the only symptom.
Pictures of mpox
Mpox on finger, phase 1
Mpox on finger, phase 2
Mpox on finger, phase 3
How the mpox virus spreads
Anyone can get mpox, and infections with the virus occur in all age categories. Most of the recent infections so far have involved MSM contact (men who have sex with men). The highest risk of infection is among men who frequently have sex with multiple partners. Mpox is transmitted through intimate contact (kissing, making love and sexual intercourse) with someone who is infected. Very occasionally, the virus is also transmitted through unprotected contact with contaminated materials (such as bedding). The virus can enter the body through the mucous membranes or through tiny wounds or tears in the skin. The virus can also spread via droplets of fluid from the blisters or from the mouth and nose, although this risk is currently considered low.
You may already be contagious before developing any visible symptoms. Some people develop flu-like symptoms or a skin rash before the blisters appear. Blisters may also form in less visible locations, such as in your mouth or inside the rectum, where they may resemble ulcers. Some people with mpox only have 1 blister. The scabs from the blisters can also transmit the virus.
Close-up of a mpox lesion
There are various ways to prevent infection. Do your part to stop mpox. You can avoid or minimise high-risk contacts to reduce your risk of getting monkeypox. Less contact involving sex and cuddling lowers the risk of infection. Quickly recognising symptoms that could indicate mpox is another way to prevent exposure to the virus. If you or someone else may have been infected, it is important not to have sexual intercourse or any intimate contact – not even with a condom. Also, make an appointment with the Municipal Public Health Services (GGDs) or your GP to get tested for Mpox as soon as possible.
If you test positive for Mpox, the GGD will start source and contact tracing. Contacts who have a high risk of exposure to a person infected with mpox are eligible for a vaccination. Your Municipal Public Service agency will inform you and your contacts about this. Vaccinating people who have MSM contact and a higher risk of Mpox exposure also helps to prevent transmission of the virus. However, further research is still needed to determine the extent to which the vaccine protects against mpox. For that reason, it is important to follow the recommendations to prevent infection even after vaccination.
Source and contact tracing
If a person tests positive for mpox, the Municipal Public Health Service (GGD) starts source and contact tracing. The aim is to find out the source of the infection and whether the infected person has been in contact with others. It is important to take part in source and contact tracing. The sooner the GGD can notify people who have been in contact with an infected person, the more likely it is that potential new infections can be prevented. This is especially important because the incubation period seems to be about 8.5 days on average at this point, but it may be as long as three weeks before someone starts showing symptoms. Sewage can serve as an indicator of public health in the Netherlands. Many diseases that occur within a group of people can be detected in sewage. RIVM is therefore conducting research into the monkeypox virus in sewage. Read more about the monkeypox virus sewage research.