Mpox has gained global attention since the 2022 outbreaks, with declining immunity from smallpox vaccinations and evolving transmission patterns – particularly through sexual contact – having contributed to its spread.
According to a recent analysis in the New England Journal of Medicine, between 1 January 2022 and 18 August 2024, a total of 45 652 cases of mpox were reported from 12 African countries: Burundi, Cameroon, Central African Republic, Congo, Ivory Coast, DRC, Kenya, Liberia, Nigeria, Rwanda, Uganda – and South Africa. These cases resulted in 1 492 deaths, for a case fatality rate of 3.3%.
In South Africa, 30 cases have been reported, five in 2022 and 25 last year. With only one case linked to travel history there is growing concern about undetected community transmission, potentially due to mild or asymptomatic infections.
Recently, Professor Sinead Delany-Moretlwe, Director of Research at Wits RHI, alongside key partners including the National Institute for Communicable Diseases (NICD), the University of Cape Town (UCT), the African Health Research Institute (AHRI), the Desmond Tutu HIV Foundation (DTHF), and community based NGOs, were awarded a South African Medical Research Council (SAMRC) grant to study the seroprevalence of the virus in high-risk populations in South Africa.
Study objectives and impact
Over the next 24 months, researchers will conduct serological surveys across Gauteng, KwaZulu-Natal and the Western Cape. The study aims to:
• Establish a baseline seroprevalence of mpox among high-risk groups;
• Monitor infection trends and identify at-risk populations;
• Assess clinical, virological, and immunological characteristics of infected individuals; and
• Strengthen community-based surveillance for early detection.
Action crucial
According to the NEJM analysis – among the authors are experts from the Africa CDC including Dr Jean Kaseya, and Professor Salim Abdool Karim, Centre for the Aids Programme of Research in SA (CAPRISA) – the spread of the virus is a cause for international concern.
On the continent, they suggested, vaccination of at-risk populations under 40 should be initiated to prevent future outbreaks.
However, they wrote, because of the limited available vaccine supply, the more targeted ring-vaccination approach is a short-term option, although such a programme is challenging to implement when surveillance systems are weak.
And, they added, the ongoing outbreak of cases in this region is not solely an African problem; it is a global health concern that requires a co-ordinated international response.
As seen with Ebola, Zika and Covid 19, localised diseases can quickly escalate into global crises. Equitable access to vaccines is crucial.
The support of high-income countries with vaccine stockpiles to provide mpox vaccines as global solidarity with Africa will enable a successful response to the threat posed by the virus worldwide. Failure to provide such access will repeat the mistakes from the Covid-19 pandemic, they warned in the NEJM.
Findings
The purpose of their analysis was to describe the changes in the epidemiology of mpox cases in Africa leading up to and after the 2024 declaration of mpox as a public health emergency in Africa and worldwide.
They concluded that the high mpox disease burden in the region, especially in the DRC – with a rising number of cases, high case fatality rate, and high degree of spread to other previously mpox-free African countries – was not to be taken lightly by the global community.
The recently announced Wits RHI research project is a welcome step towards the fight against the killer virus.
Study details
Evolving Epidemiology of Mpox in Africa in 2024
Nicaise Ndembi, Morenike O. Folayan, Allan Komakech, Kyeng Mercy, Sofonias Tessema, Placide Mbala-Kingebeni, Christian Ngandu, Ngashi Ngongo, Jean Kaseya, and Salim S. Abdool Karim.
Published in New England Journal of Medicine on 29 January 2025
Abstract
Background
For decades after the identification of mpox in humans in the Democratic Republic of Congo (DRC) in 1970, the disease was largely confined to the rural areas of Central and West Africa and thus did not garner broad attention. On August 13, 2024, mpox was declared a Public Health Emergency of Continental Security (PHECS) by the Africa Centres for Disease Control and Prevention (Africa CDC), a notice that was followed the next day by a declaration of a Public Health Emergency of International Concern (PHEIC) by the World Health Organisation.
Methods
In this study we analysed all mpox cases and deaths, based on clinical or laboratory diagnosis, that were reported to the Africa CDC from January 1, 2022, to October 30, 2024, to identify temporal variations, geographic distributions, and epidemiologic trends.
Results
>From January 1, 2022, to August 18, 2024, a total of 45 652 mpox cases were clinically diagnosed and laboratory-confirmed in 12 African countries. These cases resulted in 1 492 deaths (case fatality rate, 3.3%). From 2022 to 2024, weekly laboratory-confirmed mpox cases increased by a factor of 2.8 (from 176 to 489 cases), whereas all weekly reported cases (including those with a clinical diagnosis) increased by a factor of 4.3 (from 669 to 2900 cases). The DRC, which had reported approximately 88% of mpox cases in Africa in 2024, had 19,513 cases before the emergency declaration, with a case fatality rate of 3.1% – a weekly average of 591 cases as compared with 281 in 2023. In 2024, six African countries reported their first imported mpox infections, with Burundi also reporting local transmission.
Conclusions
The high mpox disease burden in Africa, especially in the DRC – with a rising number of cases, high case fatality rate, and high degree of spread to other previously mpox-free African countries – is cause for increased international concern. Case detection, contact tracing, public health measures, and affordable vaccines are needed to implement interventions in the DRC to reduce the risk of global spread of the virus.
NEJM article – Evolving Epidemiology of Mpox in Africa in 2024 (Open access)
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Incorrect diagnoses delayed SA man’s mpox treatment
Call for action as DRC mpox spreads via heterosexuals
Sierra Leone declares mpox emergency
Mpox vaccine doses head for Africa’s worst hit countries, including SA