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Mpox

Clade I Mpox Outbreak Originating in Central Africa

There is currently an outbreak of clade I mpox in several countries in Africa. Clade I is a type of mpox that tends to cause more severe infections than the type that caused the global outbreak starting in 2022, clade II. The current clade I outbreak was declared a Public Health Emergency of International Concern by WHO on August 14, 2024. More information is available on the CDC webpage Clade I Mpox Outbreak Originating in Central Africa. The risk of clade I mpox in the United States is currently low. All cases of mpox in Oregon have been clade II.

If a patient has mpox-like symptoms and has traveled to a country with spread of clade I mpox, clinicians or LPHAs should call the ACDP on-call epidemiologist at 971-673-1111, extension 3 to coordinate clade-specific testing.

Countries with spread of clade I mpox currently include:

  • Burundi
  • Central African Republic
  • Democratic Republic of the Congo
  • Republic of the Congo
  • Rwanda
  • Uganda

Two doses of mpox vaccine, JYNNEOS, is recommended for people traveling to countries with spread of clade I mpox who anticipate sexual contact with a new partner(s) while traveling, regardless of gender identity or sexual orientation. This is in addition to existing recommendations.

Clade I outbreak resources

Disease Information


Mpox, formerly known as monkeypox, is a disease caused by monkeypox virus. Mpox is a DNA virus related to smallpox. In 2022, there was an outbreak of mpox among humans in many countries around the world, including the United States. Since that time, mpox has continued to circulate among humans worldwide, including in Oregon. Anyone can be affected by mpox. However, most Oregonians who have had mpox are gay, bisexual, and other men who have sex with men. Transgender and nonbinary people have also been disproportionately affected. There is a vaccine available for mpox: JYNNEOS. Two doses of vaccine against mpox reduces, but does not eliminate, the risk of infection. However, vaccinated people who do get mpox have milder symptoms and are less likely to be hospitalized.

Mpox is transmitted person to person, most commonly through close skin-to-skin contact with someone who has mpox. This can include intimate contact and sex. Mpox can also be spread by direct contact with rash, scabs, or bodily fluids from a person with mpox. 

Much less commonly, mpox can also be spread by touching objects, fabrics, and surfaces that have been used by a person with mpox. Illness typically starts with fever, chills, feeling ill, and swollen glands. Around the same time or within five days, rash appears. The rash may start on the genitals, in the rectum or around the anus, in the mouth, or on skin of the face, arms, legs, or torso. Rash symptoms typically start like a pimple with an area of red skin underneath then may get bigger, form indentations, and fill with fluid or pus. It usually takes two to four weeks to heal over with fresh skin. Some people can transmit mpox before they notice they have symptoms. 

Prior to the 2022 outbreak, mpox mainly affected people in certain countries of Western and Central Africa. In these areas, mpox spreads mainly from animals to people. Mpox was originally named “monkeypox” because it was first found in a colony of monkeys. The animal reservoir for the virus, or the main animal species that the virus usually spreads in, is not known. However, it is believed that small mammals, such as rope and sun squirrels, giant-pouched rats, and African dormice may carry the virus, particularly in West and Central Africa. Mpox has not been found in wild animals outside of Africa.

There are two subtypes of the mpox virus: clade I and clade II. “Clade” is the name for a subtype of a virus. Historically, we have found clade I mpox in certain countries in Central Africa and the Congo Basin and clade II mpox in certain countries in Western Africa. Clade I has caused more severe disease than clade II. The global outbreak of mpox in 2022 was caused by the milder subtype, clade II.


Disease Reporting

What is required?

If a patient has mpox-like symptoms and has traveled to a country with spread of clade I mpox, clinicians or LPHAs should call the ACDP on-call epidemiologist at 971-673-1111, extension 3 to coordinate clade-specific testing. 

For Health Care Providers and Clinical Laboratories

Health care providers and clinical laboratories are required by law to report confirmed, probable and suspect cases of monkeypox to the local health department immediately, day or night at 971-673-1111.  Health care providers are also asked to report clinically diagnosed or empirically treated cases of mpox as suspect cases.

For Local Public Health Authorities

Vaccination and Prophylaxis

The primary vaccine used to prevent mpox is JYNNEOS. JYNNEOS is recommended for some people as outlined in the JYNNEOS vaccine guidance. JYNNEOS is also recommended for some people traveling to countries with outbreaks of clade I mpox, as outlined in the CDC Health Alert Network message from 9/23/2024. Two doses offer the best protection against mpox.  JYNNEOS can also be given after an exposure to mpox to try to prevent or reduce the severity of infection. While it is still possible to get mpox after being vaccinated, it is less likely. People who do still get mpox after being vaccinated are usually less sick than people who are unvaccinated and get mpox. If you have already gotten two doses of JYNNEOS, no additional doses or boosters are currently recommended.

Testing

For Health Care Providers

More information about identifying potential mpox is available at CDC's clinical recognition page. Testing for mpox is available at many commercial laboratories. Any healthcare provider can test for mpox, and specimen collection is simple.

For Community Members

If you have symptoms of mpox, talk to your healthcare provider about testing. Depending on your symptoms and how severe they are, some places you could go for mpox testing include:

  • Your primary care provider
  • A sexual health clinic
  • An urgent care clinic
  • An emergency room
  • A travel health clinic.

If you don't have a healthcare provider or healthcare insurance, call 2-1-1 or your local public health authority and someone can help you find a clinic or healthcare provider. 

Data 

Oregon Mpox data are available in weekly and monthly reports. Once you click on the links below, you will be able to select your disease of interest.

See Also 

General Public 

Local Public Health Authorities 





CDC Factsheet