What is mpox, previously called monkeypox?

Answer From Pritish K. Tosh, M.D.

Mpox, previously called monkeypox, 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

The Centers for Disease Control and Prevention (CDC) monitors cases that have been reported in countries that don't often have mpox, such as the United States. In the 2022 mpox outbreak, the CDC is monitoring many cases of mpox 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 5 to 21 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:

  • Fever
  • Skin rash
  • Headache
  • Muscle aches and backaches
  • Chills
  • Tiredness
  • Swollen lymph nodes

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. 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 provider 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 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.
  • 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 providers may suggest that people who have been exposed to mpox get vaccinated. Some people who are at risk of being exposed 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 drinking enough liquids 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 providers 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, care providers may offer vaccinia immune globulin, which 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
  • Blindness
  • 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 provider.

With

Pritish K. Tosh, M.D.

Dec. 01, 2022