What is Mpox
The monkeypox virus has been endemic, meaning it regularly affects inhabitants of certain regions, but is virtually non-existent in the rest of the world. Experts say this smallpox is less contagious than the human version of the disease. Smallpox, which has a mortality rate of about 30%, was eradicated more than 40 years ago. The World Health Organisation (WHO) certified the end of the disease in 1980, after a major global vaccination effort.
Although less serious, monkeypox can have more severe consequences in children, pregnant women or people with immune suppression due to other health conditions such as HIV.
This infection was discovered in 1958. The name monkeypox came about because this virus was first isolated after it affected monkey colonies. The first recorded case in humans occurred in 1970.
Monkeypox is therefore a zoonotic disease, as it is transmitted from animals to humans. Zoonotic diseases can be caused by viruses, bacteria, parasites or fungi.
In the case of monkeypox, the disease is caused by the Orthopoxvirus virus, of the Poxviridae family. Infections caused by poxviruses usually result in the formation of lesions, skin nodules or a rash spread throughout the body. This is why the name Poxviridae was given, as the word pox is the translation of ‘vesicle’ in English.
The new outbreak that began in 2022 is affecting several countries around the world where the disease is not endemic, including the United States, Canada, Australia, and many European countries such as the United Kingdom, France, Germany, Italy, Spain, and Portugal.
What are the symptoms?
This disease is usually mild and self-limiting, meaning that specific treatment is not usually necessary. The disease resolves spontaneously and most patients recover within a few weeks.
Although it is a disease associated with visible skin lesions, the World Health Organisation (WHO) warns that the infection begins with a set of non-specific signs and symptoms (lasting 1 to 5 days), followed by more characteristic symptoms.
Early symptoms include:
- Fever
- Headache
- Muscle aches
- Enlarged lymph nodes
- Fatigue
About 5 days after the onset of the first symptoms, skin and mucosal lesions (rash) appear on the skin, similar to blisters. These lesions first appear on the face and then spread throughout the body, including the hands, feet and genitals.
What do these blisters look like?
The blisters appear as a rash (which appears 1 to 3 days after the onset of fever), about 2 to 5 mm in diameter, a flat area, not palpable on the skin, accompanied by a change in colour. On lighter skin, it appears as a reddish colour, while on darker skin it is characterised by discoloured areas.
These lesions progress through the stages of vesicles, pustules (usually painful), followed by umbilicated lesions before ulcerating, and finally forming a crust that eventually falls off over 2 to 4 weeks. The lesions generally develop at the same stage simultaneously.
In summary, the stages of blister formation are:
- Exanthema (flat spots appear accompanied by itching).
- Vesicle (a blister filled with fluid forms).
- Pustule (the fluid contained in the blister becomes infected and purulent).
- Ulcer (when the blister ruptures, exposing deeper tissue).
How can you prevent this infection?
Unlike other infections, condoms cannot offer complete protection against transmission, as contact with infected lesions may be sufficient for transmission to occur.
There are several measures you should take to prevent infection with the monkeypox virus.
If there is a possibility that you are infected, you should:
- Avoid close contact with other people until the lesions have healed, including the scabs falling off;
- Alert everyone you have been in close contact with since the onset of symptoms to possible signs and symptoms;
- Not share personal items, including clothing, bedding, and towels;
- Wash clothes and textiles in a washing machine with hot water (above 60°C) and detergent, using a long wash cycle;
- Clean hard surfaces with chlorine detergents and allow them to air dry.
It's important to be aware of blisters and other symptoms, because intimate contact during sexual intercourse, including kissing, touching, oral sex, and penetrative sex, are routes of transmission. Contaminated sex toys can be another vehicle for spreading the infection, so they need to be used responsibly and kept clean.
You should seek immediate medical attention for clinical evaluation if:
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A rash appears anywhere on your body without another explanation;
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You experience one or more early symptoms of monkeypox infection, such as fever above 38 °C, headaches, muscle or back pain, fatigue, or swollen lymph nodes;
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In the 21 days prior to symptom onset, you had contact with a confirmed or probable case of monkeypox, or you traveled to countries in West or Central Africa.
How is Mpox transmitted?
According to the Portuguese Directorate-General of Health (DGS), the incubation period—from exposure to symptom onset—is usually 6 to 16 days, but can range from 5 to 21 days. Transmission from asymptomatic contacts has not been reported. It is believed that the virus is transmitted when the infected person is symptomatic.
Learn more on the DGS website.
Transmission can occur from person to person through direct contact with bodily fluids or lesions on broken skin or mucous membranes (including eyes, nose, mouth, and genitals), or indirect contact via objects contaminated with lesion material, such as clothing or bedding.
Monkeypox can also be transmitted through respiratory droplets (which do not travel long distances, so prolonged close face-to-face contact is required), or when an individual has lesions in the mouth or throat.
Although monkeypox is not considered a sexually transmitted infection in the typical sense, transmission between sexual partners can occur through intimate contact with infected skin or mucosal lesions. However, this close contact is not limited to sexual activity and can also happen in crowded settings, such as bars or concerts.
It is important to understand that transmission can occur until all scabs have fallen off and the underlying skin is fully healed. The scabs themselves may also contain contagious viral material.
How is Mpox treated?
As mentioned, most people infected experience a mild, self-limiting illness, so there is generally no need for specific therapy. Clinical care mainly focuses on managing and treating symptoms, including fever, painful sores or skin lesions, discomfort from swollen lymph nodes, or any other related conditions. Staying well-hydrated is essential to help reduce fever-related discomfort and prevent dehydration.
Infected individuals should rest whenever possible.
People with comorbidities, immunosuppressive conditions, pregnant individuals, or children under 8 years old are at higher risk of severe disease and may require medical treatment, which can include specific antiviral medications for smallpox, for example.
