The outbreak of the MPOX pandemic in Africa is another example of how infectious diseases that are perceived as “someone else’s problem” and primarily affect poor developing countries can suddenly become an unexpected global threat.
Mpox was discovered in 1958 (in captive monkeys, hence the original misname “monkeypox”), and the first human case was identified in 1970. For decades thereafter, the disease was largely neglected by science and health authorities, and was considered a rare infectious disease of remote rural areas of tropical Africa, of no significance to the rest of the world.
When a massive Mpox outbreak hit the developed world in 2022, increased research funding led to a surge in scientific studies. On just one medical search engine, more research results have been published since April 2022 than in the previous 60 years.
The global Mpox outbreak in 2022–23 occurred despite repeated calls by African researchers for greater global investment in diagnostic, therapeutic and infection prevention tools for Mpox.
The WHO has now declared the current increase in Mpox cases in Central Africa an international health emergency.
This is the highest alert level for events that pose a risk to the public health of other countries and require a coordinated international response.
We are infectious disease researchers who have worked on HIV, SARS-CoV-2 and other viral infections.
The recent story of Mpox is another reminder that an infectious disease that appears in one corner of the world should not be considered someone else’s problem, as it can suddenly spread quickly and widely.
It also highlights the global inequity in resource distribution and access to vaccines, diagnostics and treatments. These have been made available in many developed countries and helped contain the global outbreak, but are still largely lacking in most countries in Africa.
The 2022 outbreak: a total surprise
The disease was renamed “Mpox,” but the name of the virus remains “monkeypox” (MPXV) for now. It is closely related to the smallpox virus.
MPXV was considered a zoonosis endemic in parts of Central and West Africa. Infection occurred mainly through close contact with wild mammals, especially through handling bushmeat. However, sustained transmission from person to person did not occur.
Only very rarely have cases been observed outside endemic areas, due to infected travelers or the import of infected small mammals.
This changed dramatically in 2022, when a massive, rapidly evolving global outbreak caused over 99,000 laboratory-confirmed cases in 116 countries. At its peak in August 2022, over 6,000 cases were reported each week.
This outbreak came as a complete surprise, as most cases were reported from non-endemic countries and mostly affected men who had sexual intercourse with men who had recently been infected through sexual contact.
Although most cases were not particularly clinically severe and the death toll is just over 200, the World Health Organization declared the global outbreak a public health emergency of international concern on July 23, 2022.
Fortunately, the number of cases soon declined sharply due to a combination of behavioral changes and vaccinations of at-risk groups.
In many affected high-income countries, modern vaccines and antiviral drugs with efficacy against Mpox have been made available.
These were developed and stockpiled in the United States and Europe, primarily in preparation for a possible bioweapon attack using a smallpox virus.
The 2022 global outbreak was caused by MPXV clade II, which is endemic to West Africa and not as virulent as MPXV clade I, which has so far only occurred in the Congo Basin. This first MPXV public health emergency of international concern was declared in May 2023.
Upswing in Africa
There has been an increase in MPOX cases in the African region since 2023.
Africa is the continent that encompasses the areas where MPXV has long been endemic. Today, it represents a complex mosaic: cases follow the endemic, largely zoonotic pattern that was predominant in the earlier cases associated with the 2022 global outbreak, for example in South Africa. Of particular concern is the increasing number of MPXV clade Ib infections reported from the Democratic Republic of Congo.
New, more dangerous strain: The current clade I MPXV strain (formerly called the Congo Basin strain) is more virulent than the clade II (West African) strain, resulting in a higher fatality rate.
The epicenter of the current outbreak is in South Kivu province in the east of the Democratic Republic of Congo. It has the potential to trigger a major pandemic.
There is a distinct epidemiological pattern with persistent chains of transmission from person to person, often through sexual means.
The virus that causes the disease belongs to the newly defined clade Ib. It has mutations characteristic of human-to-human transmission, which is estimated to have been occurring since September 2023.
The number of cases is rising rapidly, although many suspected cases are probably not tested and thus not counted as confirmed. To make matters worse, a commonly used test misses infections with this virus lineage. Adults are mainly affected. The mortality rate is higher than during the global outbreak in 2022.
This outbreak has already resulted in cases of MPOX in several neighboring countries, including some countries (such as Kenya) where MPOX has never been seen before.
The challenge is enormous. The east of the Democratic Republic of Congo is plagued by numerous problems, including natural disasters, violence and infectious diseases, including measles, cholera and poliomyelitis.
In recent years, the wider region has experienced the second largest Ebola outbreak on record, posing significant challenges despite the availability of vaccines and treatments.
