The deterioration mpox outbreak in the Democratic Republic of Congo (DRC) is alarming and calls for urgent global action.
The disease, formerly known as monkeypox, has resurfaced in the DRC as a result of clade I, which is different from clade IIb, the strain responsible for the global outbreak in 2022.
In May 2022, an unexpected outbreak emerged in countries with no previous history of mpox transmission. Given the global health risk and the need for a coordinated response, the World Health Organization (WHO) declared the outbreak a Public Health Emergency of International Concern (PHEIC) on 23 July 2022.
The global health community mobilized quickly to deploy tests, vaccines, and therapies to help contain the outbreak, most successfully in communities in the United States and Europe.
Thanks to the rapid action, the number of cases fell globally and the PHEIC was lifted in May 2023. WHO called for further prioritization of efforts in Africa.
However, the response did not reach Africa, where mpox has been a recurring problem since it was first discovered in 1970 in the Democratic Republic of Congo.
In addition to the lack of financial support, the response may have been poorly tailored to the local context, as the transmission dynamics and affected populations of clade IIb differed from those historically observed in the DRC and now reported with clade Ib. Prevention and protection messages thus likely required more tailored approaches.
While the outbreak has been declining globally, the DRC has been dealing with a worsening mpox clade I outbreak and the emergence of a new variant since 2023.
Clade I has historically been found in the DRC, and the new variant, clade Ib, is more contagious, causes more severe disease, and has a higher mortality rate than clade IIb. This year, more than 14,000 cases and 511 deaths have been reported in the DRC – a significant increase from the ~4,000 median cases reported annually between 2016 and 2022.
In response to the worsening outbreak in the DRC and the regional spread of cases in Africa, WHO announced last week that it will soon convene the International Health Regulations Emergency Committee to assess whether the Clade I outbreak should be declared a PHEIC.
At the same time, the Africa Centres for Disease Control and Prevention (Africa CDC) said it would “most likely” declare the first-ever Public Health Emergency of Continental Security (PHECS) in response to the worsening outbreak next week.
Regardless of the Committee's decision, given the threat to global health security and human health, it is crucial that the global community unites and provides strong support to all affected regions, in particular the DRC and Africa, to control and ultimately eliminate mpox.
Why is clade I mpox of concern?
In 2023, as cases in the DRC began to increase and new geographic areas were affected, genomic sequencing identified a new variant of mpox, known as clade Ib. Genetic changes in the virus have made it more difficult for diagnostic tests to detect it, potentially leading to missed cases.
Furthermore, this is the first time that clade I has been transmitted through sexual contact. However, the transmission dynamics are still unclear.
These variables have led to an escalating outbreak of mpox clade I in the DRC. This outbreak now affects every province in the country and poses a serious threat to children under 15 years of age, who account for most cases and deaths.
Vulnerability may arise from immunosuppression by infections such as measles, reduced herd immunity due to the discontinuation of smallpox vaccination in 1980, and changes in the environment.