What is mpox, previously called monkeypox?
Answer From Pritish K. Tosh, M.D.
Mpox is a rare disease caused by the mpox virus. This virus usually affects rodents, such as rats or mice, or nonhuman primates, such as monkeys. But it can occur in people.
Mpox usually occurs in Central and West Africa. Cases outside of Africa are often due to:
- International travel.
- Imported animals.
- Close contact with an animal or person with mpox.
Starting in 2022, mpox cases were reported in countries that don't often have mpox, such as the United States. The Centers for Disease Control and Prevention (CDC) continues to monitor cases that have been reported throughout the world, including Europe and the United States.
What are the symptoms of mpox, previously called monkeypox, and what does mpox look like?
Mpox symptoms may start 3 to 17 days after you're exposed. The time between when you're exposed and when you have symptoms is called the incubation period.
Mpox symptoms last 2 to 4 weeks and may include:
- Skin rash.
- Swollen lymph nodes.
- Muscle aches and backaches.
About 1 to 4 days after you begin having a fever, a skin rash starts.
The mpox rash often first appears on the face, hands or feet and then spreads to other parts of the body. But in cases linked to the outbreak that started in 2022, the rash often started in the genital area, mouth, or throat. The mpox rash goes through many stages. Flat spots turn into blisters. Then the blisters fill with pus, scab over and fall off over a period of 2 to 4 weeks.
You can spread mpox while you have symptoms. So from when your symptoms start until your rash and scabs heal.
See your health care professional right away if you have a new rash or any mpox symptoms, even if you don't know anyone with mpox.
How does the mpox virus spread?
The mpox virus causes mpox. The virus spreads through close contact with an infected animal or person. Or it can spread when a person handles materials such as blankets that have been in contact with someone who has mpox.
The mpox virus spreads from person to person through:
- Direct contact with rashes, scabs or body fluids of a person with mpox.
- Extended close contact (more than four hours) with respiratory droplets from an infected person. This includes sexual contact.
- Clothes, sheets, blankets or other materials that have been in contact with rashes or body fluids of an infected person.
- An infected pregnant person can spread the mpox virus to a fetus.
Mpox spreads from an animal to a person through:
- Animal bites or scratches.
- Wild game that is cooked for food.
- Products, such as skins or furs, made of infected animals.
- Direct contact with body fluids or rashes of animals with mpox.
What can I do to prevent becoming infected with or spreading the mpox virus?
Take these steps to prevent infection with or the spread of the mpox virus:
- Avoid close contact with people who have a rash that looks like mpox.
- Avoid handling clothes, sheets, blankets or other materials that have been in contact with an infected animal or person.
- Isolate people who have mpox from healthy people.
- Wash your hands well with soap and water after any contact with an infected person or animal. If soap and water aren't available, use an alcohol-based hand sanitizer.
- Avoid animals that may carry the virus.
Some smallpox vaccines can prevent mpox, including the ACAM2000 and Jynneos vaccines. These vaccines can be used to prevent mpox because smallpox and mpox are caused by related viruses.
Health care professionals may suggest that people who have been exposed to mpox get vaccinated. Some people who are at risk of exposure to the virus in their work, such as lab workers, may get vaccinated too.
The CDC doesn't recommend that everyone get vaccinated against mpox at this time.
What is the treatment for mpox?
Treatment for most people with mpox is aimed at relieving symptoms. Care may include managing skin damage from the mpox rash, drinking enough liquids to help keep stool soft, and pain management.
If you have mpox, isolate at home in a separate room from family and pets until your rash and scabs heal.
There is no specific treatment approved for mpox. Health care professionals may treat mpox with some antiviral drugs used to treat smallpox, such as tecovirimat (TPOXX) or brincidofovir (Tembexa).
For those unlikely to respond to the vaccine, a health care professional may offer vaccinia immune globulin. This has antibodies from people who have been given the smallpox vaccine.
What are the complications of mpox?
Mpox complications can include:
- Severe scars on the face, arm and legs.
- Other infections.
- Death, in rare cases.
The type of mpox virus spreading in the 2022 outbreak, called Clade II, rarely leads to death.
Remember that mpox is rare in the U.S. and the mpox virus doesn't spread easily between people without close contact. But if you have a new rash or any symptoms of mpox, contact your health care professional.
July 25, 2023
Pritish K. Tosh, M.D.
See more Expert Answers
- AskMayoExpert. Monkeypox. Mayo Clinic; 2023.
- Monkeypox. Centers for Disease Control and Prevention. https://www.cdc.gov/poxvirus/monkeypox/. Accessed July 11, 2023.
- Interim clinical guidance for the treatment of monkeypox. Centers for Disease Control and Prevention. https://www.cdc.gov/poxvirus/monkeypox/clinicians/treatment.html. Accessed July 19, 2022.
- Monkeypox. World Health Organization. https://www.who.int/news-room/fact-sheets/detail/monkeypox. Accessed July 14, 2023.
- Monkeypox. Merck Manual Professional Version. https://www.merckmanuals.com/professional/infectious-diseases/pox-viruses/mpox-monkeypox. Accessed July 14, 2023.
- 2022 US monkeypox outbreak. Centers for Disease Control and Prevention. https://www.cdc.gov/poxvirus/monkeypox/response/2022/index.html. Accessed July 14, 2023.
- WHO recommends new name for monkeypox disease. World Health Organization. https://www.who.int/news/item/28-11-2022-who-recommends-new-name-for-monkeypox-disease. Accessed Nov. 29, 2022.
- Maredia et al. Supportive care management recommendations for mucocutaneous manifestations of monkeypox infection. Mayo Clinic Proceedings. 2023; doi: 10.1016/j.mayocp.2023.01.019.