Mpox outbreak in Africa: clade I mpox virus infection

WHO declares mpox outbreak a public health emergency of international concern

• This updates the news item of 23 August 2024

On the 14th of August 2024, the World Health Organization (WHO) declared the increasing number of mpox cases reported in the African Region, notably the Democratic Republic of the Congo (DRC), a Public Health Emergency of International Concern (PHEIC) [1].

Background

Mpox is an infection caused by the mpox virus. There are 2 distinct clades of the virus: clade I and clade II. Historically, clade I mpox has been associated with a higher risk of people with the infection developing severe illness or dying, compared to clade II. In May 2022, an outbreak of clade II mpox occurred globally. This outbreak predominantly affected gay, bisexual and other men who have sex with men.

Prior to 2024, clade I mpox had only been reported in 5 countries in central Africa. However, recent cases in additional countries within Central and East Africa mark the first known expansion of its geographical range, heightening the risk of spread beyond the region.

In 2023, the Democratic Republic of Congo (DRC) reported its highest number of clade I mpox suspected and confirmed cases on record. High case numbers have continued to be reported in 2024 [1]. Since July 2024, confirmed cases of clade I mpox have also been reported for the first time in Burundi, Kenya, Rwanda and Uganda with some having links to the DRC. Sweden and Thailand have reported confirmed cases of clade I mpox in a traveller with links to countries involved in the current clade I outbreak. [2, 3]

No clade I mpox cases have been reported in the UK to date [4, 5].

As of 22nd August 2024, the countries in central and east Africa where clade I cases have been reported are:

• DRC
• Republic of the Congo
• Central African Republic
• Burundi
• Rwanda
• Uganda
• Kenya
• Cameroon
• Gabon

The countries where there may be a risk of clade I mpox exposure (based on sharing a border with the DRC) currently include:

• Angola
• South Sudan
• Tanzania
• Zambia

Mpox symptoms and management

Mpox is an infectious disease caused by the mpox virus. Mpox can be transmitted when a person comes into close contact with an infected, human, animal or contaminated material.

Person-to-person spread can occur through:

• Direct contact with skin lesions or scabs (including during sexual contact, kissing, cuddling or other skin-to-skin contact).
• Contact with clothing or linens (such as bedding or towels) used by someone with mpox.

While more information is emerging, there is a potential risk of mpox spreading if you are close to an individual with mouth lesions of mpox when they are coughing or sneezing.

The first symptoms of mpox include:

• a high temperature
• a headache
• muscle aches
• backache
• swollen glands
• shivering (chills)
• exhaustion
• joint pain

A rash or pus-filled lesions then usually appear 1 to 5 days after the first symptoms. The rash (spots, blisters or ulcers) often begins on the face, then spreads to other parts of the body. This can include the mouth, genitals and anus. The number of sores can range from one to several thousand.

Advice for travellers

Before you travel

Check Foreign Commonwealth and Development Office (FCDO) advice on whether it is advised to travel to your intended destination. This also includes information on entry requirements, safety and security.

Check our Country Information pages for the latest guidance on vaccination, malaria and other health risks.

Before travelling to affected areas you should:

• Check with a health professional that you are fit to travel. In particular, pregnant and immunosuppressed people are known to be at higher risk of severe infection.
• Check your travel health insurance before you go.

Vaccination

The UK does not currently recommend pre-travel vaccination for mpox. The JCVI continues to review latest data on the current clade I mpox outbreak and will continue to update vaccination recommendations accordingly.

Please refer to the Green Book - Immunisation against infectious disease for further information about vaccinations recommended prior to travel.

While you are away

Mpox can be spread through close contact of any kind, including through sexual and non-sexual contact.

You can reduce your risk while travelling by taking sensible precautions to protect yourself from infection:

• Reduce touch or sexual contact, especially with individuals with a rash.
• Wash hands often with soap and water or an alcohol-based hand sanitiser containing at least 60% alcohol. Keep your hands away from your eyes, nose, and mouth. If you need to touch your face, make sure your hands are clean.
• Avoid touching potentially contaminated items such as bedding/clothing or sharing eating utensils/cups, food or drink with a person who has, or may have, mpox.
• Avoid animals when travelling and avoid eating or preparing meat from wild animals (bushmeat) or using products (creams, lotions, powders) derived from wild animals.

For more information on the risk of clade II mpox and sex, please see the public health advice for gay, bisexual and other men who have sex with men.

For advice for people living with HIV, see the British HIV Association (BHIVA) statement on mpox (monkeypox) virus.

When you return

If you have just arrived at a UK airport or port of entry having recently travelled to any of the mpox affected countries, and have any new spots, blisters or ulcers, you should speak to a member of port or border staff to get advice.

If you have visited one of the affected countries and develop symptoms within 21 days of returning to the UK, please isolate at home and call NHS 111 for advice, letting them know your travel history.

See current advice on the NHS mpox page.

Returning Workers Scheme

Any organisation deploying UK resident staff to areas affected by mpox clade II virus, in response to the outbreak should register with the UKHSA Returning Workers Scheme (RWS).

The current list of countries can be found here: Operational mpox HCID (clade I) case definition - GOV.UK (www.gov.uk). This list of countries may change in the future as the epidemiology of the current outbreak is rapidly evolving. Further information on the scheme is available here.

Advice for health professionals

Health professionals who suspect a case of mpox should contact the local infection clinician (microbiology, virology infectious disease and genitourinary medicine as appropriate). Infectious disease specialists should contact the Imported Fever Service to discuss testing and management. Guidance is available on diagnosis, testing and infection control measures and will continue to be updated. Specific guidance on managing cases of clade I mpox can be found here.