Monkeypox is a viral infection in which a person develops fever, fatigue, muscle aches, and a rash all over the body. Most cases resolve within 2 to 4 weeks.
This rare disease was found mainly in central and western African countries. Cases without international travel or contact with imported animals have been recently reported indicating spread of this infection.
Monkeypox was first detected in Denmark in 1958 in a colony of monkeys used for research. This is how it came to be called “monkeypox.” The first human case occurred in 1970 in the Democratic Republic of the Congo (DRC).
In May 2022, several cases of monkeypox were reported in countries where monkeypox does not normally occur. These include countries in Europe, North and South America, the Middle East, and Australia.
Monkeypox is caused by Orthopoxvirus. It is similar to the virus that causes smallpox, but is much less severe. The virus is transmitted when a person comes into close contact with an infected animal, human, or material contaminated with the virus.
Monkeypox can be transmitted from animal to human when a person:
- Comes in contact with an infected animal
- Gets bitten or scratched by an infected animal
- Handles or consumes bushmeat
Monkeypox can be transmitted from human to human when a person:
- Comes in close contact with body fluids, sores, or scabs from an infected person
- Comes in close contact with contaminated material (such as clothing or linens)
- Is exposed to large respiratory droplets during face-to-face contact
- Has intimate contact during sex including kissing and cuddling (it is unclear if the virus can spread through seminal or vaginal fluids)
The symptoms of monkeypox are similar to that of smallpox, but they are milder. Symptoms usually appear in 1 to 3 weeks after exposure.
Early symptoms include:
- Muscle aches
- Swollen lymph nodes (only occurs with monkeypox, typically does not occur with smallpox)
- Sore throat and cough
A rash appears a couple of days after fever and can be found on all parts of the body. The rash starts as flat spots that become raised bumps, which fill with fluid, then pus. The bumps may be painful. Soon they crust over and form itchy scabs that fall off and heal over. Once all scabs fall off, you are no longer contagious.
Symptoms may last for 2 to 4 weeks.
Exams and Tests
Your health care provider can diagnose monkeypox by looking at the rash and asking questions about your medical history.
Your provider will take specimens from your skin lesions and send them for testing. A PCR test (polymerase chain reaction test) can confirm the diagnosis.
Currently, there is no specific treatment for the monkeypox virus. In most people, symptoms usually go on their own in 2 to 4 weeks.
Certain people may be at risk for more severe disease and may need to be hospitalized and given supportive care:
- People with severe symptoms
- People whose immune system is not working well
- People who are pregnant or breastfeeding
- Children younger than 8 years old
Antivirals used for smallpox may be helpful in treating monkeypox.
In most people, symptoms go away within 2 to 4 weeks. Rarely, severe cases may lead to death.
When to Contact a Medical Professional
Contact your provider if you:
- Think you may have been exposed to monkeypox
- Develop symptoms of monkeypox
- Have an unexplained rash
If you have monkeypox, you should call your provider if:
- Your symptoms do not improve
- The rash becomes infected
- You have nausea, vomiting, diarrhea, or dehydration
- The rash spreads to your eyes, mouth, genitals, or anus
To prevent the spread of monkeypox virus:
- Avoid contact with animals that are in areas where the virus occurs
- Avoid contact with any material that may have been contaminated by a sick animal
- Avoid contact with a person who has monkeypox
Use PPE (personal protective equipment) such as gloves and masks while caring for a patient who has monkeypox illness.
Centers for Disease Control and Prevention website. Monkeypox: clinical recognition. www.cdc.gov/poxvirus/monkeypox/clinicians/clinical-recognition.html. Updated May 27, 2022. Accessed June 3, 2022.
Centers for Disease Control and Prevention website. Monkeypox: interim clinical guidance for the treatment of monkeypox. www.cdc.gov/poxvirus/monkeypox/treatment.html. Updated May 29, 2022. Accessed June 3, 2022.
Centers for Disease Control and Prevention website. Monkeypox: signs and symptoms. www.cdc.gov/poxvirus/monkeypox/symptoms.html. Updated July 16, 2021. Accessed June 3, 2022.
Centers for Disease Control and Prevention website. Monkeypox: transmission. www.cdc.gov/poxvirus/monkeypox/transmission.html. Updated May 29, 2022. Accessed June 3, 2022.
World Health Organization. Monkeypox. Fact sheets. www.who.int/news-room/fact-sheets/detail/monkeypox. Updated May 19, 2022. Accessed June 3, 2022.
World Health Organization. Monkeypox. Q&A. www.who.int/news-room/questions-and-answers/item/monkeypox. Updated May 20, 2022. Accessed June 3, 2022.
Review Date 6/21/2022
Updated by: Jatin M. Vyas, MD, PhD, Associate Professor in Medicine, Harvard Medical School; Associate in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital, Boston, MA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.