The virus is part of a family of viruses called poxviruses. They include smallpox. Poxviruses cause a painful rash that can look like pimples or blisters. A poxvirus infection can also cause health problems and, rarely, death.

Mpox was first reported in 1958 after it sickened monkeys in a research center in Denmark. It became known as monkeypox even though the monkeys were not the source. Scientists believe rodents carry the virus.

The first human case was reported in 1970. In 2003, the United States had an outbreak of 47 cases in six states linked to pet prairie dogs.

No. While people can get the virus during sex, it is not considered a sexually transmitted disease because it can spread in other ways.

Health officials say two strains of the virus have been reported since the current outbreak started in 2022.

Symptoms typically last two to four weeks.

The first symptoms are:

• Fever
• Intense headache
• Swollen lymph nodes
• Back pain
• Muscle aches
• Lack of energy

Next symptoms are:

• Within one to three days of the fever, an infected person will develop a painful rash that looks like pimples or blisters.
• The skin bumps (lesions) most commonly form on the face, hands and feet, and in the mouth and throat. They can also form on the genitals and eyes.
• The bumps fill with fluid and then turn into scabs.

The virus spreads mostly through direct or indirect contact with an infected person’s skin lesions, body fluids or personal items, such as clothing, bedding or towels.

OHSU experts say that casual contact, such as a handshake, is highly unlikely to spread the virus. Scientists are studying whether it can spread through airborne droplets but believe that’s rare.

If you are pregnant and become infected with the virus, you can pass it:

• To your fetus through the placenta.
• To your newborn during close contact after birth.

Infected people should be considered contagious from the time their symptoms start until the scabs from their rash fall off and a new layer of skin forms.

OHSU experts say that once people have recovered from the virus, they can no longer spread it.

An incubation period is the time between getting infected and showing symptoms. OHSU experts say the incubation period for the virus is usually seven to 14 days but can range from five to 21 days.

Infectious-disease experts say that, based on what we know about closely related viruses, people who get infected or vaccinated should have long-term immunity.

Immunity can weaken for several reasons, including:

• Medications and medical treatments that suppress the immune system
• Untreated or unknown HIV infection

Information is limited on how long the vaccine remains effective.

The virus can cause a range of complications such as:

• Scarring
• Secondary infections, including tonsillitis
• Pneumonia
• Vision loss
• Pregnancy complications including pregnancy loss

The WHO says the case fatality ratio (the portion of diagnosed cases that lead to death) has been 3% to 6% in recent years. Because not all cases are diagnosed or reported, the fatality rate among all cases is lower.

OHSU experts recommend that you avoid:

• Having unprotected contact with an infected person’s skin lesions, body fluids or personal items.
• Having lengthy face-to-face contact (within 6 feet) with an infected person without masks.

The CDC recommends that people consider limiting sex partners and avoiding sex parties to reduce the risk of getting the virus until they are vaccinated.

If you share a household or health care setting with an infected person, you can use common household disinfectants to kill the virus on shared surfaces and personal items. Learn more about cleaning and disinfecting.

Anyone can get the virus. But most cases have been in men, and mostly among men who have sex with men, according to the WHO.

People who have not gotten a smallpox vaccine also may be more vulnerable to the virus, the CDC says. The United States stopped routine smallpox vaccinations in 1972.

For those who have had a smallpox vaccination, though, one childhood dose can offer up to 75 years of protection, OHSU researchers found.

See these related questions to learn more about those considered at high risk of getting mpox:

• Who can get vaccinated at OHSU?
• Who should get the Jynneos vaccine?

The U.S. Food and Drug Administration has approved two vaccines for poxviruses, the family of viruses that includes mpox:

• Jynneos has emergency authorization for use in people ages 18 and older who are at high risk of infection with the virus. Jynneos can also be used for people under 18 under FDA “expanded access” rules, which include informed consent and other criteria.
• ACAM2000 is approved for use against smallpox in people who are considered at high risk of infection. The FDA has made it available for use against mpox under “expanded access” rules.

Neither vaccine contains smallpox or mpox. Both are made from a related virus that does not cause disease in humans. Both spur the immune system to make antibodies to fight infection.

Both vaccines may have side effects including pain, swelling, fever and rash.

Both Jynneos and ACAM2000 have FDA approval for use against poxviruses. That means they were cleared for use after extensive testing in people.

Jynneos is linked to few possible complications. It can be given even to people with weakened immunity.

ACAM2000 is linked to a risk of myocarditis and pericarditis, potentially serious inflammation of the heart muscle and surrounding tissue. Risk is higher for those who have never had a smallpox vaccine, such as most people under age 60.

The CDC says ACAM2000 should not be given to people who:

• Have severely weakened immunity
• Are living with HIV
• Have skin conditions such as eczema or psoriasis
• Have heart disease
• Have eye disease treated with topical steroids
• Are pregnant
• Are less than 12 months old

ACAM2000 is given in one dose with a two-pronged needle. The needle is dipped in vaccine and then used to quickly prick a small section of arm skin multiple times.

Jynneos is given in two doses, typically 28 days apart. A dose is usually injected under the skin of the underside of the forearm. Jynneos may also be given in the upper back, under the skin just below the shoulder blade.

After exposure: OHSU experts say getting a vaccine within four days of exposure can stop an infection. Getting a vaccine within 14 days of exposure can reduce the length and severity of an infection.

Before exposure: The Oregon Health Authority says some people at high risk of infection should get or be considered for vaccination. See "Who should get the Jynneos vaccine?"

OHSU has Jynneos. See "Who can get vaccinated at OHSU?" to learn who qualifies.

Vaccines are available for people who have been exposed to mpox or who are considered at high risk of infection.

• OHSU has Jynneos. See "Who can get vaccinated at OHSU?" to learn who qualifies.
• Call your health care provider.
• Call your public health department:
  • Oregon health departments
  • Washington health departments
  • Clackamas County Health, Housing and Human Services
  • Multnomah County Health Department
  • Washington County Health & Human Services

Anyone can get mpox infection, but some groups may be at higher risk. The mpox vaccine (Jynneos) is available to anyone who is eligible. You do not need to share your personal risk.

You can get the mpox vaccine if you:

• Are 18 or older.
• Do not have symptoms that are or could be from mpox (rash, fever, swollen lymph nodes, muscle aches, backache or headache).
• Have no prior history of mpox infection.
• Have not had a severe reaction to the mpox vaccine.

To schedule an appointment:

• Call the Physicians Pavilion pharmacy at 503-494-7570 during pharmacy hours:
  • 8 a.m.-9 p.m. weekdays, 9 a.m.-5:30 p.m. weekends.
• Use our vaccine scheduling tool.

After exposure:

If you’ve been exposed to mpox, you should get vaccinated right away, ideally within four days of exposure.

You qualify for vaccination at OHSU if you:

• Are 18 or older.
• Do not have symptoms that are or could be from mpox (rash, fever, swollen lymph nodes, muscle aches, backache or headache).
• Have been exposed to the virus in the last 14 days.

You can also: 

• Contact your provider or schedule an in-person or virtual Immediate Care visit.
• Contact your public health department:
  • Oregon health departments
  • Washington health departments
  • Clackamas County Health, Housing and Human Services
  • Multnomah County Health Department
  • Washington County Health & Human Services

Under Oregon Health Authority guidelines, people should get or be considered for a Jynneos vaccination if they:

• Have been in contact with people who have a presumed or confirmed case of mpox.
• Are at higher risk of mpox infection. 
• Are lab workers who do mpox tests.
• Are health care workers who have been exposed to mpox without personal protective equipment.

The virus can cause more severe disease in children, according to OHSU experts. 

The CDC says children may be eligible for vaccination if they have had close personal contact with  someone who has or may have mpox. 

No. OHSU experts say most Americans age 60 and older have had the smallpox vaccine, which also protects against mpox. OHSU researchers found that the smallpox vaccine provides immunity for up to 75 years after a single childhood dose.

If you think you have been exposed to mpox, OHSU experts encourage you to:

• Check yourself for symptoms for 21 days after your most recent exposure. This includes taking your temperature twice a day to check for fever. (The Oregon Health Authority recommends checking for a new rash; a fever of 100.4 or higher; swollen lymph nodes; and chills.)
• Stay away from group events.
• Avoid public transportation.
• Avoid donating blood, tissue, breast milk, sperm or organs.

If you develop symptoms, you are encouraged to:

• Stay away from people and pets (isolate).
• Seek testing and medical care.
• Cover your lesions if possible.
• Wear a mask.
• Keep your used clothing and bedding in a separate bag or container that can be disinfected, and wash your clothing and bedding separately from other laundry.

Yes. Ask your health care provider about getting a test. If you do not have a health care provider, call your local public health department:

• Oregon health departments
• Washington health departments
• Clackamas County Health, Housing and Human Services
• Multnomah County Health Department
• Washington County Health & Human Services

Most people who get mpox recover without treatment within two to four weeks.

For more serious cases, the CDC and FDA allow the use of tecovirimat, or TPOXX, an antiviral drug approved for smallpox.

Tecovirimat is in limited supply in Oregon. OHSU is working with state health officials to ensure the safety of those who receive tecovirimat.

Most people who get mpox can care for themselves at home. The most common concerns are rashes (lesions), pain and itching.

How to care for rashes:

• Keep them clean and dry.
• Cover them with gauze, long sleeves, pants or gloves.
• Avoid scratching a rash, popping a lesion or picking a scab.
• Avoid shaving the skin around rashes or lesions.
• Apply povidone-iodine ointment (Betadine) to reduce the risk of spreading the virus and to speed healing.
• If a lesion is producing fluid, dispose of any soaked gauze where others can’t come into contact with it. Place clothing or bedding that has come into contact with the fluid in a separate bag or container that can be washed or disinfected afterward.

If you touch a rash:

• Wash your hands with soap and water or a hand sanitizer with alcohol in it.
• Avoid touching sensitive body parts such as the eyes, nose, mouth, genitals or anus. A rash that gets in the eyes can cause vision loss.

If you have a rash on your hands:

Wear gloves when touching shared surfaces or objects. Reusable gloves should be washed with soap and water after each use.

If you have a rash in your mouth:

Rinse with saltwater several times a day. If the rash is painful, talk to a health care provider about a prescription mouthwash or a local anesthetic.

How to manage pain or itching:

• Pain: Take ibuprofen (Advil, Motrin) or acetaminophen (Tylenol).
• Itching: Take an oral antihistamine (Benadryl). Apply a numbing gel (lidocaine), steroid cream, calamine lotion or ointment (Aquaphor, Vaseline).

In general:

• Stay home and rest as much as possible.
• Wear a mask around others if you have a rash in your mouth or throat.
• Drink lots of fluids.

When to seek medical care:

• Pain: If you have pain that can't be managed with over-the-counter medications.
• Rashes: If a rash spreads toward an eye or another area that may be especially sensitive, including broken skin; and if rashes spread over more than 5% or 10% of your body surface. (The arm is about 9% of your body surface).
• Infection: If you think you have signs of a secondary infection, including fever (100.4 or higher), chills or sweats, swollen lymph nodes or a new rash.