In July 2024, WHO shared a disease outbreak news update on the mpox situation in South Africa. It stated that, between 8th May and 2nd July 2024, the International Health Regulations (IHR) National Focal Point (NFP) of the Republic of South Africa had notified WHO of 20 confirmed mpox cases, including three deaths. Response measures have been implemented with WHO support, but it warns that “confirmed cases are only a small proportion of all cases that might have occurred, and that community transmission is ongoing”.
Cases reported to WHO
WHO was notified of 20 confirmed mpox cases between 8th May and 2nd July 2024, including three deaths. This means that the case fatality ration (CFR) is 15%. The cases were reported in three of nine provinces: Gauteng, Western Cape, and KwaZulu-Natal. The cases are all males between the ages of 17 and 43 years and are “almost all self-identified as men who have sex with men (MSM)”. Most are persons living with HIV, unmanaged or recently diagnosed HIV infection and advanced HIV disease (AHD), and one person has diabetes.
All cases were symptomatic with “extensive” skin lesions; 18 required hospitalisation. None of the cases reported a history of international travel or attendance of high-risk social gatherings. The type of exposure reported is sexual contact. For the first 16 cases, 44 contacts were identified in KwaZulu-Natal, 39 in Western Cape, and 55 in Gauteng province. Although three of the four initial cases in KwaZulu-Natal were epidemiologically linked, at least seven in Gauteng province were not, which suggests that community transmission is taking place.
Genomic sequencing from five confirmed cases identified sub-clade IIb MPXV; this is the clade linked to the multi-country outbreak.
WHO’s assessment
WHO states that the “sudden” appearance of unlinked cases without a history of international travel, the high HIV prevalence among confirmed cases, and the high case fatality ratio indicate that community transmission is underway. Therefore, the cases detected to date likely represent a “small proportion” of cases in the community and it is unknown how long the virus has been circulating. This is partly attributed to the “lack of early clinical recognition” of infection with which South Africa gained “little experience” during the ongoing global outbreak, potential pauci-symptomatic manifestation of disease, or delays in care-seeking behaviour due to “limited access to care of fear of stigma”.
Most of the transmission in the initial cases is linked to recent sexual contacts among men, so the risk for gay men, bisexual men, other men who have sex with men, trans and gender diverse people, and sex workers is “moderate” in comparison with the “low” risk to the wider public in the country. WHO refers to recent Joint United Nations Programme on HIV/AIDS (UNAIDS) data, which estimate HIV prevalence among MSM in South Africa to be around 30%, with only 44% of this group receiving antiretroviral therapy. This group is “extremely vulnerable” to severe mpox disease and death.
Risk of evolution
WHO is concerned that the outbreak in South Africa will “continue to evolve” considering:
- The high likelihood of under-detection and under-reporting of local transmission, given that reported cases have almost exclusively affected the most vulnerable
- All detected cases have presented with severe disease and extensive skin lesions, which could lead to more viral transmission and risks poor outcomes for patients
- Although government and partners are mobilised to introduce treatment for affected patients and vaccines for people at risk, these countermeasures are not yet widely available in the country
- Public awareness of mpox and information about modes of transmission or possible amplifying events or risk of exposure in sex-on-premises venues remains limited in South Africa
- Concurrent outbreaks of mpox are occurring in Africa and elsewhere, increasing the risk of further transmission
We will consider efforts to contain mpox at the Congress in Washington next April, so do get your tickets to join us to participate in these discussions, and don’t forget to subscribe to our weekly newsletter here.
