Mpox in the United States and Around the World: Current Situation

What to know

  • There are two kinds of the virus that causes mpox, clade I and clade II. You can't tell which kind of mpox someone has by looking at them.
  • Each clade of the virus has subclades, clade Ia and clade Ib; clade IIb. Outbreaks from the subclades can have different characteristics, like who they affect, how they're spread, or even how many deaths they cause.
  • There are outbreaks of clade I mpox in the Democratic Republic of the Congo (DRC) that began in 2023. The outbreak on the eastern part of the country has spread into neighboring countries in 2024.
  • Mpox spreads through close or intimate contact with a person with mpox. This could mean living in close quarters, or it may mean through sexual contact with a person with mpox.
  • It may also spread by direct contact with contaminated items and surfaces used by people with mpox.
  • In areas that regularly have mpox cases in Western and Central Africa, people can also get mpox from contact with infected wild animals.
  • The disease is not known to spread in settings where only respiratory spread is possible – for example, across rooms, in markets or classrooms, etc.
  • CDC recommends vaccination with two doses of JYNNEOS for people in the United States at risk of mpox. The vaccine is FDA approved for and expected to protect against both clades and all subclades of mpox.
  • CDC is working with public health partners in the United States and throughout Africa to monitor for mpox cases and increase surveillance capacity, in addition to other activities.
  • Clade II mpox cases continue to spread at low levels in many countries around the world.

Current situation

In the United States

  • There have been no reported cases of clade I mpox in the United States.
  • In the United States, clade II mpox is still circulating at low levels.
  • Because many cases in areas that regularly have mpox outbreaks have been in children, many people have concerns about the risk of mpox in children in the United States. Here's what we know:
    • Children have historically gotten mpox in endemic areas in Western and Central Africa often because they have contact with wild animals in those areas that carry the disease then pass it to humans; those humans can then spread mpox to close household contacts. The animals are called "reservoirs." Animals in the United States do not carry the virus that causes mpox.
    • The high number of children with mpox reported in the current DRC outbreak also likely reflects spread within households. Numerous factors probably contribute to this, including crowded households and poor sanitary conditions. We don't expect to see the same sort of risk if mpox were introduced in the United States for several reasons, including different household makeup and size, access to disinfecting products, and improved access to medical care and information about caring for patients.
    • CDC simulated clade I mpox outbreaks resulting from close-contact transmission within and between households (household clusters) in the United States to better understand the potential impact of this transmission route. This modeling included children. The results indicate that close-contact transmission within and between households is unlikely to result in a large number of mpox clade I cases in the United States.

Across the globe

  • There are outbreaks of clade I mpox in Central and Eastern Africa. There have been a few cases in people who traveled from that region to other countries, where they got sick.
    • Clade I has two subclades, clade Ia and clade Ib.
    • In Central Africa, people have gotten clade Ia mpox through contact with infected dead or live wild animals, household transmission, or patient care; a high proportion of cases have been reported in children younger than 15 years of age.
    • Subclade Ib was recently identified in eastern DRC and has been spread through intimate and adult sexual contact between different demographics, including heterosexual spread with sex trade workers. So, far clade Ib has a lower case-fatality rate than clade Ia mpox.
  • The ongoing global outbreak of clade II mpox has caused more than 100,000 cases in 122 total countries, including 115 countries where mpox was not previously reported. The outbreak is caused by the subclade IIb.
  • Historically, only Cameroon in West Africa had cases of both clade I and clade II mpox, but they were seen in different parts of the country. To date, no other country has reported cases due to both clades, with the exception of the recent travel-associated clade I cases in India, Sweden, and Thailand.
Clade I Mpox Outbreak Originating in Central Africa
An outbreak of clade I mpox is occurring in Central and Eastern Africa
Ongoing Clade II Mpox Global Outbreak
Information on the ongoing outbreak of Clade II mpox

Global mpox cases: data dashboard and map

Notes: Case data reported in humans to WHO since January 1, 2024, are provided for situational awareness and subject to change. Confirmed cases include those laboratory-confirmed as monkeypox virus and may include cases only confirmed as orthopoxvirus. For more information and additional limitations, see WHO-reported data at 2022-24 Mpox (Monkeypox) Outbreak: Global Trends (shinyapps.io).

Source: 2022-24 Mpox Outbreak: Global Trends. Geneva: World Health Organization, 2024. Available online: https://worldhealthorg.shinyapps.io/mpx_global/ (last cited: August 27, 2024)

What CDC is doing

  • In the United States, CDC has adapted systems from the ongoing clade II outbreak to be able to rapidly detect, contain, and manage clade I cases should they occur domestically.
  • CDC works closely with state, tribal, local, and territorial public health departments to provide recommendations for clinical management, diagnosis, and prevention of mpox cases in the U.S.
  • CDC continually increases capacity in communities across the United States for early detection of mpox through existing surveillance systems, including wastewater testing.
  • In the United States, CDC works with key public health and community partners to get the word out about vaccinating and reducing mpox risk.
  • CDC raises awareness for healthcare providers, including the latest guidance for considering mpox as a possible diagnosis in certain patients.
  • CDC works with researchers and partner organizations to increase health equity around mpox and ensure that the populations most affected by mpox have access to the mpox vaccine.

CDC and in-country partners across Africa work together on disease surveillance, laboratory capacity, strengthening workforce capacity, case investigation, strengthening case management, infection prevention and control, and vaccine strategy and plannin.

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Content Source:
National Center for Emerging and Zoonotic Infectious Diseases (NCEZID)