Monkeypox is caused by a virus that belongs to the same group as the smallpox virus. It is usually present in some countries in Central and West Africa (“endemic countries”). However, there is currently a multi-country outbreak of Monkeypox involving countries that do not usually have the disease, and without apparent links to endemic countries. Urgent investigations into the extent of spread are underway (1).
Human to human: an infected person can spread the disease to others in several ways. The virus is present in large respiratory droplets, such as those expelled when a person laughs, coughs or sneezes. If a healthy person inhales these droplets, they can catch the disease. Typically, this only occurs during direct, prolonged face-to-face contact with a sick person.
Monkeypox can also be spread through direct contact with the rash and body fluids of an infected person or with virus-contaminated objects, such as bedding or clothing. “Transmission between sexual partners, due to intimate contact during sex with infectious skin lesions seems the likely mode of transmission” (1).
Prior to this outbreak, human to human transmission was uncommon. Animal to human transmission can occur through contact with an infected animal, from an animal bite, or contact with its blood or other bodily fluids. Infection can also occur if a person touches the rash on an infected animal's skin - which sometimes happens during food preparation. In endemic countries, Monkeypox virus is found among rodents and non-human primates, but it is assumed that any mammal can catch the disease.
People usually become sick about 7 to 14 days after they have had contact with the Monkeypox virus, but it can take as long as 21 days. The first symptoms are flu-like: fever, headache, muscle aches, backache, swollen lymph nodes, chills and a general feeling of discomfort and exhaustion. About one to three days after the fever begins, patients develop a rash. It usually first appears on the face, and affects the arms, legs, hands, and feet. However, in the current outbreak the rash can involve the genital and perianal area. The rash progresses through several stages, forming blisters, which become pustular, before crusting and falling off. People are infectious until all the crusts have fallen off (2). Most people usually recover within about two to four weeks. Children and people with immune deficiency are at higher risk of severe disease.
The diagnosis is made by laboratory testing of blood and swabs of the rash. Generally, only specialised laboratories can test for Monkeypox.
Isolation: Infected people should remain in isolation until their rash heals completely. They should avoid contact with immunosuppressed persons and pets. Abstaining from sexual activity and close physical contact is also advised. Most cases can remain at home with supportive care.
contacts of Monkeypox cases should self-monitor for the development of symptoms up to 21 days from the last exposure to a case (3). Some authorities are recommending close contacts isolate for 21 days.
Vaccines exist but are not widely available. Smallpox vaccination provides protection against Monkeypox.
People who have been vaccinated against Smallpox in the past appear to have some protection against Monkeypox. A newer vaccine that protects against Smallpox and Monkeypox is available in a few locations, for use in people who may be exposed through their occupation, under strict protocols.
Prevention is through:
- Observing good personal hygiene.
- Washing hands well and often.
- Avoiding close contact with sick people.
- Avoiding touching objects which have been in contact with a sick person.
In areas where Monkeypox is present in animals, additional preventive measures are:
- Avoiding contact with wild animals.
- Avoiding touching objects which have been in contact with animals.
- Avoiding preparing or eating "bush meat" (wild game).
1 - European Center for Disease Prevention and Control 20 May 2022
2 - United States Center for Disease Control and Prevention 28 September 2018
3 - European Center for Disease Prevention and Control 23 May 2022