What is mpox, previously called monkeypox?

Answer From Pritish K. Tosh, M.D.

Mpox is an illness caused by the monkeypox virus. The virus can spread to humans from an animal host, such as rodents or nonhuman primates such as monkeys. The virus also can spread between people.

In humans, mpox can cause flu-like symptoms and an itchy, painful rash. Treatment for most people with mpox is to relieve symptoms. There is an mpox vaccine. People at high risk of the illness or who were recently exposed to the virus may be able to get the vaccine. Most people recover without complications. But some people can get seriously ill from mpox. Rarely, mpox can be deadly.

What are the symptoms of mpox?

Mpox symptoms tend to start within 21 days after you come in contact with the virus. You may have symptoms that are like the flu, including a sore throat, runny or stuffy nose, and a cough.

Other symptoms may include:

  • Swollen lymph nodes.
  • Fever and chills.
  • Headache.
  • Backache.
  • Feeling very tired, called fatigue.
  • Muscle aches and backaches.

About 1 to 4 days after the flu-like symptoms, people usually get a skin rash. Often, the mpox rash first appears on the face, hands or feet and then spreads to other parts of the body. The rash also may start in the genital area, mouth or throat. There may be many rash spots, a few spots or just one.

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. Throughout the time when your symptoms start until your rash and scabs heal, you can spread mpox to others. This includes pets or other animals.

See your healthcare professional right away if you have a new rash or mpox symptoms, even if you don't know anyone with mpox.

How do you get mpox?

The virus that causes mpox can spread to humans from animals or from person to person. There are two types of virus: Clade 1 and clade 2. These clades also are called clade I and clade II. The term "clade" is the name for a group of related viruses.

  • Clade 1 tends to spread regularly in Central Africa. It tends to cause more-serious illness with mpox and is linked to more deaths from mpox. It may spread more easily than clade 2.
  • Clade 2 tends to spread regularly in West Africa. Clade II causes less severe disease and is less likely to cause death than clade I.

Both types of the virus may spread in other places around the world, often linked to international travel or animal trade.

The virus can spread from person to person through:

  • Direct contact with the rashes, scabs or body fluids of a person with mpox.
  • Close, face-to-face contact, intimate activities and sexual contact.
  • Contact with fabrics or objects that have touched the rashes or body fluids of a person with mpox.

A pregnant person who gets mpox can pass the virus to the unborn baby.

The virus also can spread to humans from direct contact with an infected animal, which includes:

  • Animal bites or scratches.
  • Contact with the animal's waste or body fluids.
  • In places where mpox spreads regularly, processing animals for food, including hunting or trapping, skinning, cooking, or eating.

Rodents, such as gerbils, hamsters or guinea pigs can be infected with viruses in the same family as the monkeypox virus. But to date, no cases of these animals getting mpox have been reported.

And it's not clear whether pets, such as cats or dogs, get sick from mpox. But health agencies think people with virus infections could spread the virus to a pet through petting, hugging or other close contact.

If you're concerned about your pet, ask a veterinarian for information on your pet's risk of mpox.

Who is at high risk of serious illness with mpox?

Most people with mpox get better without having serious illness. Groups that have a higher risk of serious mpox illness are:

  • People who have a seriously weakened immune system.
  • Children younger than age 1.
  • People who have had eczema.
  • Pregnant people.

An infection with the clade 1 virus is more likely to cause serious disease than is infection with clade 2.

What are complications of mpox?

Complications from mpox include:

  • Other infections in organs or throughout the body. These infections can be serious and lead to permanent changes, such as loss of vision, or death.
  • People with mpox rash in their genital areas can have serious pain that needs to be treated in the hospital.
  • An mpox rash in the mouth or throat can cause trouble eating or drinking. If you can't take in enough fluids, you may need to get fluids through a vein.
  • In some people, mpox can lead to mood disturbance or a brain infection called encephalitis.

Is there a vaccine to prevent mpox? What are other ways to prevent mpox?

You can prevent mpox in a few ways.

  • Get the mpox vaccine if it's recommended for you.
  • Avoid close contact with people who have a rash that looks like mpox.
  • Avoid animals that may carry the monkeypox virus.
  • If you are the caretaker for a person with mpox, limit your contact with objects and fabrics the person uses.
  • Wash your hands with soap and water, especially after any contact with a person or animal with mpox. If soap and water aren't available, use an alcohol-based hand sanitizer with at least 60%alcohol.

The vaccine for mpox is called Jynneos. People age 18 and older can get the vaccine depending on their risk of coming in contact with the virus. You are up to date with an mpox vaccine after two doses given four weeks apart. If you already had mpox, you don't need to get the vaccine.

Your healthcare professional may suggest that you get an mpox vaccine if you are at higher risk of coming in contact with the virus that causes mpox, including:

  • People who know or think they've been exposed to the virus, or who had a sex partner diagnosed with mpox within the last two weeks.
  • People who have sexual risk factors for mpox. This includes men who have sex with men and who also have a newly identified sexually transmitted infection and have multiple sex partners.
  • People who may be exposed through their workplace. This includes some healthcare settings, labs or places where people work with animals that could get the virus.

For other groups of people, health agencies do not recommend an mpox vaccine. If you have questions about how you can protect against mpox, contact a healthcare professional.

How is mpox diagnosed?

Mpox can be diagnosed by your healthcare professional. You may be asked to recall when you might have been exposed to the virus. You may have an exam in which the healthcare professional looks at your rash. Samples of fluid from the rash might be sent to a lab and tested for mpox.

What is the treatment for mpox?

Treatment for most people with mpox is aimed at easing symptoms. Care may include preventing skin damage from the mpox rash or using pain medication you can get without a prescription.

If you have mpox, stay at home and apart from other people and pets you live with until your rash and scabs heal.

For people who have a very high risk of serious illness or death, a healthcare professional may treat mpox with an antiviral medicine.

Mpox in the U.S.

Mpox is rare in the U.S. and the virus doesn't spread easily. But if you have a new rash or symptoms of mpox, contact your healthcare professional. If you are at high risk of coming into contact with the virus that causes mpox, take steps to lower your risk of the illness.

With

Pritish K. Tosh, M.D.

Oct. 05, 2024