What is mpox?
Mpox is an illness caused by infection with the mpox virus. It is related to the smallpox virus. While less severe and much less contagious than smallpox, mpox can be a serious illness.
It can spread from infected humans, animals, and materials contaminated with the virus. Mpox primarily spreads through close, personal, skin-to-skin contact with people who have mpox symptoms, such as rashes and sores. There is a
vaccine to protect aāgainst mpoxā. The risk of mpox to the general public remains low.
Is mpox a new disease?
No, mpox is not a new disease. Mpox (formerly known as monkeypox) was first discovered in 1958. Mpox is endemic (regularly found) in parts of west and central African countries.ā
Since 2022, there has been an outbreak of mpox in locations where mpox was not commonly seen. This includes Europe, Canada, and the United States, including California.
Does the mpox virus have variants?
There are two types of mpox virus: clade I and clade II. The ongoing global mpox outbreak that began in 2022 is caused by clade II mpox. Clade II mpox has continued to spread at low levels with the U.S. and California since 2022.
General information about prevention, symptoms, and treatment apply to both types of mpox. The mpox vaccine is believed to be effective against both clade II and clade I mpox.
What about clade I mpox virus?
On November 15, 2024, the California Department of Public Health (CDPH) confirmed the first known case of clade I mpox (formerly known as monkeypox) in the United Statesā. This individual had recently traveled to
a region in Africa where there has been an ongoing clade I mpox outbreak; other travel-associated cases have also recently been found in Europe and Asia. At this time, there is no concern or evidence that clade I mpox is currently spreading between individuals in California or the United States. The risk to the general public remains low.
If you are traveling to areas where there is clade I mpox, see
CDC Preventing Mpox While Traveling. If you have mpox symptoms, tell your healthcare provider if you have traveled to Africa or been in close contact with someone who traveled there in the past 21 days. People with mpox symptoms shouldāÆstay away from othersā until they see their healthcare provider.
Clade I mpox has historically been thought to spread more easily and cause more severe illness than clade II mpox.āÆHowever, recent outbreaks in Africa suggest that illness severity may be more similar to clade II mpox, especially when appropriate supportive medical care is provided.
This situation is being monitored by public health authorities, including the U.S. Centers for Disease Control and Prevention (CDC) and the CDPH.
Go to Q&A: Mpox Symptomsā
Who can get mpox?
Anyone can get mpox after close physical contact with someone who has the infection.
The current risk to the general public is low. Most cases in the United States have occurred in gay, bisexual, transgender, and other men who have sex with men. Some cases were found to be infected through household contact (shared living spaces) with people infected with mpox.
How serious is mpox?
Mpox is usually a mild infection with symptoms lasting from 2 to 4 weeks. Certain people may be at higher risk for severe illness. This includes:
- āpeople with
weakened immune systemsā, such as HIV
- infants under 1 year old
- people with a history of eczema
- people who are pregnant or breastfeeding
Infections in the current global outbreak, including in California, are rarely fatal. Over 99% of people who get this form of the infection are likely to survive. However, symptoms can be extremely painful. Some people might have permanent scarring from the rashes and sores.
Go to Q&A: Mpox Symptomsā
Should parents be concerned about the spread of mpox in classrooms?āÆ
To date, no school-related mpox cases have been reported in the United States. There is very low transmission of mpox in the general population and of the few likely mpox cases in children, spread has been through household contact with someone infected with mpox.
The risk to children is
expected to remain low if clade I mpox comes to the United Statesā. Outbreaks in parts of west and central Africa, where the virus is endemic (regularly found), have historically affected more children and adolescents because of several reasons. Historically, most infections have been associated with contact to wild animals that carry mpox (e.g., hunting) that then spread within households and families. Mpox risk can also be affected by other factors such as household sizes, sanitary conditions, and access to medical care in these regions. For more information see the
CDCās Clade I Mpox in Children in Africa and Expectations for Transmission in the United States.
Can animals or pets get mpox?āÆ
Mpox has been known to infect different types of mammals in parts of west and central Africa, where the virus is endemic (regularly found). People can get mpox from direct contact with infected animals, often while hunting, trapping, preparing or eating wild animal meat (bushmeat). A
2003 outbreak in the U.S. was associated with pet prairie dogs that had shared cages with other imported animals that had mpox.
The CDC and CDPH do not believe that mpox currently poses a high risk to pets. However, transmission of mpox between people and animals can potentially occur through close contact. This includes petting, cuddling, and sharing sleeping areas or food. If you have mpox, avoid contact with animals and pets. Ask another household member, or outside friend or outside family member to care for pets until you are fully recovered. For more information, see
CDC | Pets & Mpox.āāāāāā