WHO declares mpox outbreak in Africa a public health emergency of international concern; first cases of clade Ib mpox detected in UK
The World Health Organization (WHO) declared the current mpox outbreak in Africa a public health emergency of international concern (PHEIC) on the 14th August 2024. PHEIC status aims to accelerate funding, research, and international public health measures and co-operation to contain a disease, and is the WHO’s highest level of alert possible.
The PHEIC has been declared due to the following reasons:
An upsurge of mpox cases in parts of Africa
Emergence of a new variant of mpox, known as clade Ib, which appears to be spread mainly by sexual transmission
Rapid spread of the clade Ib variant in the Eastern Democratic Republic of the Congo (DRC) and reports of cases in several neighboring countries (e.g., Burundi, Kenya, Rwanda, Uganda)
Potential to spread further across other countries in Africa, and possibly outside of Africa.
So far in 2024, over 10,000 laboratory-confirmed cases have been reported in Africa, including 36 deaths (as of 27 October 2024). The three countries with the majority of cases are the DRC, Burundi, and Uganda. The number of suspected and confirmed cases has been estimated to be approximately 44,000 cases, including over 1000 deaths; many cases are not laboratory confirmed due to limited diagnostic capacity in some African countries.[12]
Although the epidemiology is not fully understood, there are currently two distinct ongoing outbreaks in the DRC:
A clade Ia outbreak primarily in mpox-endemic areas mainly affecting children
A clade Ib outbreak in the eastern part of the country which has been rapidly spreading and reaching neighboring countries which have not previously reported mpox cases. The outbreak is affecting both children and adults, and is spreading rapidly among adults through close contact including sexual contact identified within networks of sex workers and their clients.
At the time of publication, travel-related cases of clade Ib infection have now also been reported in some countries outside of Africa including India, Sweden, Thailand, Germany, and the UK.
The first case of clade Ib mpox detected in the UK was reported on 30 October 2024. The UK Health Security Agency (UKHSA) revealed that the case was detected in London, and the person was transferred to the Royal Free Hospital High Consequence Infectious Diseases unit. The case had recently traveled to countries in Africa currently experiencing outbreaks of clade Ib mpox. Three further cases were detected in household contacts of the first case (as of 6 November 2024). Close contacts of the cases are being followed up, and will be tested and vaccinated as needed. The wider risk to the UK population remains low.[26]
It is unclear at this time whether disease caused by the clade Ib variant differs from that of the clade II variant that caused the 2022 global outbreak, or whether current vaccines are effective against the new variant.
Updated information on the situation is available from public health authorities.
WHO: 2022-24 mpox (monkeypox) outbreak - global trends Opens in new window
CDC: clade I mpox outbreak originating in Central Africa Opens in new window
This is the second time the WHO has declared an mpox outbreak to be a PHEIC, with the first one declared in July 2022 due to a global outbreak in countries that had not previously experienced cases. This outbreak was due to the clade IIb variant. The emergency was declared over in May 2023 as the number of cases had decreased significantly since their peak in August 2022.
Several outbreaks of mpox caused by different clades of the virus have occurred in different countries, with different modes of transmission and levels of risk. Outbreaks are ongoing in some countries. Mpox was first detected in humans in the DRC in 1970, and is endemic to countries in Central and West Africa.
Summary
Definition
History and exam
Other diagnostic factors
- fatigue/asthenia/malaise
- myalgia
- headache
- sore throat
- backache
- cough
- nausea/vomiting
- diarrhea
- delirium/confusion
- seizures
Risk factors
- recent travel to/living in endemic country or country with outbreak
- contact with suspected, probable, or confirmed case
- occupational exposure
- random one-time sexual encounters or multiple sexual partners
- recent tattoo or piercing
- contact with infected animal
- children (severe disease)
- pregnant women (severe disease)
- immunocompromised (severe disease)
- HIV infection (severe disease)
- acute or chronic skin conditions (severe disease)
- sexually transmitted infection
Diagnostic tests
1st tests to order
- reverse-transcription polymerase chain reaction (RT-PCR)
- CBC
- urea and electrolytes
- LFTs
- sexually transmitted infection tests
Treatment algorithm
Contributors
Authors
David L. Heymann, MD, DTM&H
Professor of Infectious Disease Epidemiology
London School of Hygiene and Tropical Medicine
University of London
Head
Centre on Global Health Security - Chatham House
London
UK
Disclosures
DLH declares that he has no competing interests.
Acknowledgements
Dr David L. Heymann would like to gratefully acknowledge Dr Tom Blanchard, the previous contributor to this topic.
Disclosures
TB is the principal investigator on an MRC/Wellcome/Newton Fund grant to make a Zika vaccine based on recombinant modified vaccinia Ankara.
Peer reviewers
Miguel G. Madariaga, MD, MSc, FACP
Infectious Diseases Consultant
Naples Community Hospital
Naples
FL
Disclosures
MGM declares that he has no competing interests.
Jimmy Whitworth, MD, FRCP, FFPH, FMedSci, DTM&H
Emeritus Professor
London School of Hygiene & Tropical Medicine
London
UK
Disclosures
JW declares that he has no competing interests.
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