Photo credit: LumerB/Getty Images

Mpox (previously known as monkeypox) is a public health emergency both in the U.S. and around the world.

“Following the COVID-19 pandemic, the mpox epidemic serves as a further alarm for the need to improve our systems for public health response and ensure rapid access to diagnostic tests, vaccines and treatments,” says Dr. Timothy Mastro, FHI 360’s chief science officer. “There are many endemic diseases around the world for which there are not comprehensive epidemic control measures. The mpox outbreak is a reminder that we need to strengthen disease detection, prevention and control measures.”

Here’s what you need to know about mpox.

What is mpox, and is it a new virus for humans?

Mpox is caused by a virus in the genus Orthopoxvirus, which includes smallpox. Mpox is mild compared to smallpox but can cause death in 1–5% of cases.

Mpox was first identified in humans in the Democratic Republic of the Congo (DRC) in 1970, after being first identified in laboratory monkeys in Denmark in 1958. It is endemic — meaning it is consistently present but usually limited to a particular region — in Central and West Africa, specifically Cameroon, Central African Republic, the DRC, Nigeria and Sierra Leone.

What is new about the current outbreak is that cases of the disease are being reported in countries where the disease has never been detected or reported previously.

How did we get here?

During May 2022, a large multi-country mpox outbreak was first reported, with a cluster of cases in the U.K. that were linked to travel in Nigeria. Cases rapidly spread across several European countries as well as North and South America.

On July 23, 2022, the World Health Organization (WHO) declared mpox a public health emergency of international concern — the highest public health alert. The U.S. Centers for Disease Control and Prevention (CDC) declared mpox a public health emergency on August 4, 2022.

Wasn’t this disease previously called monkeypox?

Yes, the virus was previously known as monkeypox because it was first seen in research monkeys. The WHO changed the name to mpox in November 2022, saying the term monkeypox could be construed as stigmatizing and racist.

How widespread is mpox? Where can I find current statistics?

The mpox epidemic has been changing rapidly throughout 2022. To obtain current statistics on the global outbreak, we recommend two primary data sources, both of which include visualizations:

• WHO’s 2022 Mpox Outbreak: Global Trends dashboard.
• The U.S. CDC’s 2022 Mpox Outbreak Cases and Data dashboard.

Who is at risk of contracting mpox?

Anyone who has close contact with someone with mpox can get the disease, regardless of age, sexual orientation or gender identity.

Still, the current global outbreak has some defining characteristics. As of December 9, 2022:

• Among cases with known data on sexual orientation, 86% are among those who identify as gay or bisexual as well as other men who have sex with men. Among cases with available data, 97% of cases are male, and the median age is 34 years.
• Among cases with available data, males between 18- and 44-years-old account for 79% of cases.
• A sexual encounter was the most commonly reported type of transmission, comprising 70% of all reported transmission events.

(Source: WHO 2022 Mpox Outbreak: Global Trends dashboard).

How is mpox spread? What are the symptoms?

Mpox can spread to anyone through:

• Direct contact with skin lesions or body fluids from someone with mpox. Direct contact can also happen during intimate contact, such as through vaginal, oral or anal sex, with someone who has mpox.
• Prolonged contact with respiratory secretions from someone who has mpox.
• Through kissing, hugging, massage and other face-to-face contact.
• Contact with objects, fabrics and surfaces that have been used or touched by someone with mpox.

The incubation period is 3–21 days, and it can be spread from the time symptoms start until the rash has fully healed.

Mpox symptoms usually start within three weeks of exposure to the virus. Early on, symptoms can include fever, headache, swelling of the lymph nodes, back pain, muscle aches and lack of energy. Typically, painful skin lesions develop one to four days after onset of fever. These rashes commonly present as blisters on the face, hands, feet, eyes, mouth or genitals.

(Source: U.S. CDC.)

How is mpox diagnosed?

For people in whom mpox is suspected, if they present with skin lesions, a health care professional will take a specimen of lesion material and send it to a laboratory for testing.

There are two types of laboratory tests that can confirm mpox: a nucleic acid amplification test (NAAT) or a conventional polymerase chain reaction (PCR) test. When testing, additional genetic sequencing is helpful to understand the epidemiology of transmission and determine the virus clade (that is, the virus subtype or group; the two mpox clades that are known currently are West African and Central African).

If you have had close contact with someone with mpox or suspect you have symptoms, you should contact your health care provider.

How is mpox treated?

Most people recover from mpox within two to four weeks without the need for medical treatment. However, some individuals may require supportive treatment as well as treatment of specific complications. Antivirals are mostly reserved for severe cases, including people requiring hospitalization, children less than 8 years old, pregnant and breastfeeding women, people living with HIV and/or people with health complications.

If someone is diagnosed with mpox or thinks they might have it, should they notify close contacts?

As soon as a suspected or confirmed case is identified, it is recommended that that person or their health care provider notify the person’s recent contacts — a process known as contact tracing. Contact tracing is necessary to promptly identify new cases and clusters of cases to provide the best clinical care, isolate cases to prevent further transmission of the disease and tailor effective control and prevention measures.

Contact tracing also helps people who are at a higher risk of developing severe disease from the virus. If they know early on that they have been exposed, they can monitor their health and seek medical care immediately if they become symptomatic.

Who should get vaccinated against mpox?

Supply of the vaccine for mpox is limited thus far to countries in the Global North, and that supply is limited as well. Vaccination is being prioritized for those at greatest risk of exposure.

Currently, two vaccines are approved by the U.S. Food and Drug Administration (FDA) for the prevention of monkeypox: JYNNEOS and ACAM2000. Only JYNNEOS is approved for the prevention of mpox in people 18 years and older. Both vaccines were developed for use against smallpox and have been demonstrated, through observational studies, to be about 85% effective in preventing mpox (source: WHO).

The U.S. CDC recommends three vaccination strategies:

1. People who have a documented exposure to someone with confirmed mpox.
2. People who have not yet been exposed to the virus but whose occupations put them at a high risk of exposure, including clinical laboratory personnel, research laboratory personnel and certain health care and public health professionals.
3. People who have not yet been exposed to the virus but who are likely to have been recently exposed or become exposed to mpox. This includes men who have sex with men, as well as sex workers.

The U.S. CDC recommends that vaccination strategies for mpox should be part of larger prevention efforts, which should include health equity principles as a foundation and strategies such as community outreach, education efforts, and communication about behavioral strategies to minimize risk.

What are some key considerations for people living with HIV in relation to mpox?

It has not been confirmed if people living with HIV are at greater risk of acquiring mpox or at risk of more severe cases. However, people living with HIV who are not virally suppressed may be at increased risk for confluent rash (that is, rashes that blend together), secondary bacterial infection of lesions and prolonged illness.

For people living with HIV, mpox may present as an atypical rash — disseminated, confluent or partially confluent — instead of as discrete lesions. People living with HIV who contract mpox who are viremic (meaning there is HIV virus in their blood) and off antiretroviral medication (ART) should begin or re-initiate ART. Most of the commonly used HIV medications are considered safe for people receiving treatment for mpox.

Finally, providers should consider offering HIV testing to those who present with mpox. This is because a study published in the New England Journal of Medicine found that, of 528 mpox infections, 41% of those infections were in people living with HIV. Importantly, three new cases of HIV were identified in those who were diagnosed with mpox (source: Thornhill, et al.). We encourage health care providers to consider a patient’s overall risk assessment as part of their treatment process.

For more information, visit the Meeting Targets and Maintaining Epidemic Control (EpiC): Mpox webpage. EpiC, which is led by FHI 360, is leveraging its foundational structure in responding to HIV to accelerate the emergency response to mpox.

Why is there so much misinformation around mpox, and how should information about mpox be communicated effectively?

While mpox is endemic in certain countries, the 2022 outbreak has made the public more aware of the virus, particularly in the U.S. and Europe. Early media reports focused on the fact that gay and bisexual men represented the majority of cases, which contributed to stigmatization and may have slowed both communication around and response to mpox in many countries.

The key is to reach and support communities most at risk of mpox without further stigmatizing them.

To do this successfully, FHI 360 recommends a two-pronged approach to increasing understanding: 

1. Communication to make the general population aware of mpox and in possession of accurate information, especially regarding how it is transmitted and how to prevent transmission.
2. Direct engagement with key affected populations to minimize their risk.

In both approaches outlined above, communication should focus on routes of transmission without emphasizing who is most affected.

When increasing knowledge among the general population, we recommend:

• Repeating accurate information multiple times to combat emerging rumors.
• Debunking myths about who is and is not at risk of contracting mpox.
• Providing factual and timely information to media covering the epidemic.

Key affected populations must not be stigmatized and must be supported to minimize their risk of contracting mpox. We recommend:

• Working with community representatives to design and adapt risk reduction messaging for their specific audiences, and then using existing trusted communities, platforms and channels to disseminate those messages.
• Integrating mpox risk reduction messaging into existing sexual health programs (such as HIV prevention and HIV/STI testing).
• Training health care providers and contact tracers to identify and avoid stigmatizing behaviors, such as labelling everyone with mpox as being members of particular groups.

Is FHI 360 involved in any projects that are responding to or studying mpox?

Yes. FHI 360 is involved in mpox projects at both the regional and country levels. We are conducting projects that span infectious disease response and preparedness as well as risk communication.

In West Africa, FHI 360 is conducting the Enhancing Global Health Security (EGHS) project, funded by the U.S. CDC. Through the EGHS project, we:

1. Provide the Regional Center for Surveillance and Disease Control (RCSDC) of the Economic Community of West African States (ECOWAS) guided prioritization of geographical areas for response based on disease burden and the capacity of the National Public Health Institutes (NPHI)/Emergency Operations Center (EOC).
2. Support the RCSDC in convening community of practice meetings for communicating regional risk.

Through the Meeting Targets and Achieving Epidemic Control (EpiC) project, FHI 360 and partners are working in six countries (Benin, Ghana, Morocco, the Dominican Republic, Jamaica and Guatemala) to respond to and bolster the response to monkeypox. This work, funded by the U.S. Agency for International Development (USAID), includes supporting countries and communities at a higher risk of contracting the disease in risk communication and community engagement activities, training and capacity building for health care providers, and community-based surveillance and contact tracing.

Further resources from FHI 360

Mpox Fact Sheet and Considerations for HIV Programs (also available in French and Portuguese). Source: Meeting Targets and Maintaining Epidemic Control (EpiC) project.

Mpox Tool for Community Based Organizations. Source: EpiC project.

Mpox Factsheet for Health Staff. Source: EpiC project.

Further reading

World Health Organization’s Mpox 2022 outbreak information

U.S. Centers for Disease Control and Prevention’s FAQ on mpox

Cited research

Thornhill JP, Barkati S, Walmsley S, Rockstroh J, Antinori A, Harrison LB, et al. Monkeypox virus infection in humans across 16 countries—April–June 2022. N Engl J Med. 2022;387: 679-91. doi: 10.1056/NEJMoa2207323.