Clade II Mpox Outbreaks around the World

Clade II mpox around the world

Prior to the 2022 global outbreak, clade II mpox was found in West Africa. There have been occasional travel-related cases in other parts of the world, including a 2003 U.S. outbreak linked to imported prairie dogs.

Since the outbreak began, clade II mpox has been seen in many countries where mpox had not previously been reported. Clusters of cases continue in many of these same countries. CDC continues to work with international partners, global health organizations, and ministries of health on mpox preparedness, surveillance, and testing.

Improved surveillance because of the ongoing capacity-building during the outbreak means cases can be found quickly. In late summer 2024, there were outbreaks in South Africa and Cote d'Ivoire.

As of summer 2025, Sierra Leone and other countries in West Africa are experiencing outbreaks of clade II mpox. CDC is tracking a recent uptick of U.S. cases of clade II across several different states linked to these outbreaks. Unlike the ongoing global outbreak, this outbreak has affected males and females about equally. Person-to-person transmission has occurred during this outbreak, including through sexual or other intimate contact. CDC is collaborating with several U.S. laboratories and in-country contacts to better understand the situation.

Since January 1, 2022, there have been a total of more than 114,000 clade II mpox cases worldwide, with more than 220 reported deaths. Overall, the number of cases worldwide have gone down steadily since the peak in 2022. In 2024, there were nearly 9,000 cases of clade II mpox around the world.

Get more information about CDC travel recommendations to countries with confirmed or suspected community transmission.

Mpox in the United States

Here's what we know about clade II mpox in the United States:

1. The number of illnesses reported recently is far below the peak of the outbreak in July and August 2022, when the national 7-day average was more than 450 cases a day (or more than 11,000 per month). U.S. case counts have remained consistent at about 200 or fewer a month since October 2024.
2. In 2023, about 1,700 cases reported. In 2024, more than 3,000 cases were reported.
3. Clade II mpox is still mostly being spread through sexual and intimate contact, with gay, bisexual, and other men who have sex with men at the highest risk of getting mpox.
4. A CDC study indicates that getting two doses of mpox vaccine works to prevent mpox. It's rare for people to get mpox after they've been fully vaccinated or recovered from a prior infection. Right now, getting more than two mpox vaccine doses (a "booster") isn't recommended.
5. Based on what we know, people who have already had mpox or have had both doses of mpox vaccine are likely to be protected against both clades of mpox. This includes clade I mpox, which is circulating in Central and Eastern Africa.
6. Most people with mpox recover fully in 2 to 4 weeks without special medicines, but there are ways to treat symptoms at home.
7. Some people with very severe mpox or who are at risk of severe mpox may need additional treatment, especially if they have a weakened immune system or an active skin condition, or pregnant or breastfeeding women.

What you should do

If you're eligible for the mpox vaccine, get vaccinated!

You're eligible for mpox vaccine if you're a gay, bisexual, or other man who has sex with men AND have other sexual risk factors.

Most new clade II mpox cases continue to be in people at higher risk for mpox who were not vaccinated with JYNNEOS.

You're also eligible if you're traveling to a country with a new clade II mpox outbreak (not related to the ongoing outbreak that began in 2022) and anticipate any of the following activities during travel: sex with a new partner; sex at a commercial sex venue; sex in exchange for money, goods, or other trade; sex in association with a large public event.

Preventing mpox spread

During the past two years, sexual behavior and other changes by people at higher risk for mpox helped reduce the spread of mpox.

If you're at risk and haven't gotten both doses of the vaccine yet, consider getting vaccinated to protect yourself.

Whether or not you've been fully vaccinated, other ways to protect yourself include avoiding close contact with people who are sick with signs and symptoms of mpox, including those with skin or genital lesions. In some cases, symptoms may be mild. If you or a sexual partner has or recently had mpox symptoms, or you have a new or unexplained rash anywhere on their body, see a healthcare provider. People who have mpox symptoms should not have sex or other close contact with people while they are ill, and until their rash is completely healed, which means scabs have fallen off and a fresh layer of skin has formed.

Also, avoid contact with contaminated materials used by people who are sick (such as clothing, bedding, toothbrushes, sex toys, or materials used in healthcare settings).

What CDC is doing

• Since 2022, CDC has increased our capacity to detect cases of mpox through existing surveillance systems, including wastewater testing.
• CDC, public health, and commercial laboratories have increased testing capacity to find cases of mpox quickly.
• CDC is working with state, tribal, local, territorial, and commercial partners to closely monitor for mpox cases so health officials can quickly respond.
• CDC works with key partners in the United States to get the word out about vaccination and reducing mpox risk.
• CDC prioritizes health equity and continues to work with partners in the community to support vaccine uptake among the communities disproportionately affected by mpox. You can see some of this work in social media videos with Dashaun Wesley in collaboration with CDC Foundation.
• CDC supports state and local health departments to increase mpox vaccine accessibility, demand, and uptake.
• CDC funds studies to better understand why people decide to get vaccinated against mpox or not. Partner organizations, including the National Coalition of STD Directors and National Coalition for Sexual Health, used this research to develop equity-centered and free communications materials and a communication toolkit.

Resources