As you are likely aware, there is an ongoing outbreak of Mpox in DRC with a specific clade of the virus with some cases reported in neighboring countries as well as a handful of cases reported from other countries. We have created this fact sheet to provide information on Mpox and on this current outbreak. Special thanks to Joey Platt at ICAP for her support.
In addition, ICAP organized a webinar on Mpox a couple of months ago which still provides relevant information.
Updates regarding the ongoing outbreak can be accessed via:
- Africa CDC website and X (formerly Twitter) account
- WHO: news on mpox
- US CDC: mpox
- PRI’s Weekly News and Science Updates on Priority Infectious Diseases
Current outbreak in the Democratic Republic of Congo and neighboring countries
Mpox has been endemic in central Africa since 1970, however, for more than a decade there has been a steady increase in the number of cases. In 2023, cases rose significantly in the Democratic Republic of Congo (DRC) with the trend continuing at an alarming pace. The current outbreak has largely been fueled by a new mpox virus strain (clade Ib) identified in DRC last year which has been found to cause more severe illness, including death, compared to clade IIb which contributed to the 2022 global outbreak. The rapid spread of this strain in DRC and neighboring countries, including Burundi, Kenya, Rwanda, and Uganda, prompted the World Health Organization (WHO) to declare the outbreak a public health emergency of international concern on August 14, 2024.
To help curb the outbreak, the Africa CDC announced that it will be partnering with Bavarian Nordic, manufacturer of the mpox vaccine JYNNEOS, to enhance local vaccine manufacturing capabilities and deliver 2 million vaccine doses to affected areas by the end of 2024 and 10 million by the end of 2025. Additionally, 215,000 doses have been procured through partnership with the European Union and are expected to arrive and be rolled out by end of August 2024.
What is mpox?
Mpox is a disease caused by the monkeypox virus, an orthopoxvirus that is similar to the smallpox virus, although causing less severe illness. There are two genetic clades of mpox – clade I and clade II – the former associated with more severe illness.
Mpox was first discovered in Denmark in 1958 in monkeys and then later discovered in humans in the Democratic Republic of Congo (DRC) in 1970. Mpox can spread both from person to person or from animals to people. Following eradication of smallpox in 1980 and the end of smallpox vaccination worldwide, mpox steadily emerged in central, east and west Africa (WHO, 2023). A global outbreak occurred in 2022–2023 due to clade II.
How is mpox transmitted?
Person-to-person transmission of mpox can occur through direct contact with infectious skin or other lesions such as in the mouth or on genitals, including:
- face-to-face (talking or breathing)
- skin-to-skin (touching or vaginal/anal sex)
- mouth-to-mouth (kissing)
- mouth-to-skin contact (oral sex or kissing the skin)
- respiratory droplets or short-range aerosols from prolonged close contact
Fomite transmission can occurby touching materials used by persons with mpox that have been contaminated with the virus (e.g., towels, sheets)
Animal-to-person transmission can occur through direct contact with an animal infected with the virus, including known carriers such as some species of monkeys or terrestrial rodents (such as the tree squirrel). Exposure by such physical contact with an animal or meat can occur through:
- Bites or scratches
- Activities such as hunting, skinning, trapping or preparing a meal
- Eating contaminated meat which is not cooked thoroughly
Health care setting transmission can occur if provider has contact with a patient with mpox without the use of personal protective equipment.
Source: WHO (2024)
What are the signs and symptoms of mpox?
Mpox causes signs and symptoms which usually begin within a week but can start 1–21 days after exposure. Symptoms typically last 2–4 weeks but may last longer in someone with a weakened immune system.
Common symptoms of mpox are:
- rash
- fever
- sore throat
- headache
- muscle aches
- back pain
- low energy
- swollen lymph nodes
Source: WHO (2023)
How is mpox diagnosed?
Mpox is diagnosed by collecting specimens directly from the rash, including skin, fluid or crusts, or biopsy where feasible. The specimen is then sent to a laboratory in which diagnosis is confirmed by the detection of viral DNA by polymerase chain reaction (PCR).
If diagnosed with mpox, the care someone needs will depend on their symptoms and their risk of developing more severe disease. People with mpox should follow the advice of their health care provider. Symptoms typically last 2–4 weeks and usually go away on their own or with supportive care, such as medication for pain or fever (e.g., analgesics and antipyretics). Please see WHO’s resource on recovering from mpox at home here for more information.
Source: WHO (2024)
Who is at risk for mpox?
Anyone who has close contact with a person or animal with mpox is at risk for infection. Certain groups may be more likely to be exposed to mpox or develop severe illness if they get mpox. These groups include:
- Children. A high proportion of cases in some affected African regions have been among children and adolescents who have been exposed through hunting or trapping activities or consumption of insufficiently cooked meat.
- Health care workers. Health workers caring for patients with mpox may be at higher risk for exposure (particularly if not using protective equipment).
- People living with HIV (PLWH) and others at risk for more severe mpox. PLWH (particularly those not on antiretroviral therapy or with late disease) and individuals with other immunocompromising conditions, pregnant women and children are at higher risk for severe mpox.
- Men who have sex with men. Most of the cases that were reported in the global 2022 outbreak as well as a small, but increasing, proportion of cases in the African region were identified among gay, bisexual and other men who have sex with men. Given the documented spread of mpox among these sexual networks, this group may be at higher risk of being exposed if they have sexual contact with someone who is infectious.
- Sex workers and their partners. Mpox can be transmitted sexually and thus, this group may be at higher risk for exposure if they have sexual contact with someone who is infectious.Cases among sex workers have been reported in the current outbreak in Africa.
Mpox prevention
Preventive measures:
- Avoid close contact with anyone who has mpox
- In areas where animals have been known to carry mpox, avoid unprotected contact with wild animals, especially those that are sick or dead (including their meat and blood) and ensure any food containing animal parts or meat be cooked thoroughly before eating
- Practice good hand hygiene (washing with soap and water or an alcohol-based hand sanitizer) and sanitation of surfaces that may have been exposed to mpox
- Wear a face mask if you are another person have been diagnosed with mpox until symptoms resolve
- Safe sexual practices, including:
- Openly communicating with partners about mpox symptoms and risks
- Exchanging contact details with sexual partners so that you can inform each other if you do develop symptoms
- Taking a break from having sex
- Reducing your number of new sexual partners, one off sexual partners, or anonymous sexual partners
- Consistently using condoms
- Avoiding group sex
- Avoiding sex-on-premises venues
- Avoiding using alcohol or drugs in sexual contexts (including chemsex)
For more information on the risk of mpox during sex and protective strategies, please see the WHO’s public health advice for gay, bisexual and other men who have sex with men, public health advice for sex workers on mpox, and public health advice on mpox and sex-on-premises venues and events.
Mpox Vaccination
There are vaccines recommended by the WHO and US CDC for use against mpox. Many years of research have led to the development of newer and safer vaccines for smallpox. Some of these vaccines have been approved in various countries for use against mpox. At present, the WHO and US CDC recommend use of MVA-BN (JYNNEOS) vaccine as two doses (four weeks apart), the LC16 vaccine (WHO recommendation only) as two doses (four weeks apart), or the ACAM2000 vaccine as a single dose when the other vaccines are not available. Studies have shown that mpox vaccines provide a good level of protection against infection and severe disease.
The WHO and US CDC currently recommend mpox vaccination for people who are at risk (for example, someone who has been a close contact of someone who has been diagnosed with mpox, or someone who belongs to a group at high risk of exposure to mpox). Additionally, the European CDC (ECDC) and US CDC recommend considering vaccination (if available) if you are eligible and plan to travel to affected areas (US CDC) or will be traveling and interacting with affected communities (ECDC).
Vaccination if given within a week of exposure to a case of mpox can prevent mpox in the contact.
Source: WHO (2024), CDC (2024)
Mpox treatment
Antivirals
An antiviral developed to treat smallpox (tecovirimat, as known as TPOXX) was approved in January 2022 by the European Medicines Agency for the treatment of mpox under exceptional circumstances and through a US CDC-held Expanded Access-Investigational New Drug (EA-IND) protocol. It is recommended for individuals with severe mpox or with underlying conditions, e.g. HIV or other immunosuppression.
Animal studies show TPOXX may potentially help to treat mpox, and trials have been ongoing to determine its efficacy. The initial results from a study in the Democratic Republic of the Congo (DRC) released in August 2024 suggest that for the clade I mpox in DRC, TPOXX did not make lesions go away any faster compared to patient who did not receive TPOXX. An ongoing study in the US is also evaluating the efficacy of TPOXX among patients with mpox.
Source: US CDC (2024)