Ongoing Mpox Outbreak Has Novel Variant, High Mortality
The WHO reports the variant, clade I MPXV, has been circulating in a region within the Democratic Republic of Congo since last year.
The WHO recently provided an update on the ongoing outbreak in the Democratic Republic of Congo, which sees a novel strain circulating and it is seeing some challenges to getting it under control.
Image credit: WHO
The World Health Organization (WHO) reported a total of 7851 mpox cases were confirmed in the Democratic Republic of the Congo, including 384 deaths, as of May 26.1
The outbreak has been ongoing since September 2023, specifically in the South Kivu province, and according to health officials has continued to spread within the province and recently to neighboring North Kivu. This outbreak has been driven by sexual contact transmission.1
WHO says the confirmation of sexual transmission of clade I was further established by the reporting in September 2023 of several new cases exposed through sexual contact with a known case in Kamituga health zone, in South Kivu province. Since then, the number of cases reported in South Kivu has continued to increase, including among sex workers and their contacts, and from an increasing number of health zones.1
This particular outbreak has been problematic for a few different reasons explain health officials. Challenges associated with it include the geographic expansion to previously unaffected areas, the appearance of this novel strain, the observed sustained community transmission driven by sexual transmission and other forms of close physical contact in the eastern part of the country, resource constraints to respond over such a wide geographic area, limited public awareness of mpox, the insufficient availability of treatment kits and lack of vaccines to date, multiple competing public health priorities, and insecurity. Based on the situation, WHO says there is a high risk associated with mpox in the Democratic Republic of the Congo.1
US Cases and Prevention
According to the Centers for Disease Control and Prevention (CDC), there have been a total 32,063 cases in the US and 58 deaths. In looking at the CDC's incidence tracker, the trend for the reported number of cases has been down to just a handful in the last couple of weeks. And in its most recent reporting—the week ending June 9—the 7 day moving average, which calculates the average number of cases per day in the previous 7 days, it was just 1 case.2
Last month, the CDC’s MMWR published data on the Jynneos vaccine for the prevention of mpox and the highly efficacious immunization. Investigators reported an estimated incidence rate of mpox was reported to have occurred in less than 0.8% in fully vaccinated persons.3
According to the MMWR, from May 2022 – May 2024, 271 mpox cases in fully vaccinated persons were reported to CDC from 27 US jurisdictions. The CDC data shows that among 32,819 probable or confirmed mpox cases during this time period, a total of 24,507 (75%) occurred in unvaccinated persons.3
“Of these 271 cases, 51 (19%) occurred during 2024. Vaccination status was missing for 3737 (11%) cases; an additional 4304 (13%) cases were excluded from analysis because the patient had received only 1 Jynneos vaccine dose or had received the second dose <14 days before illness onset, or because other exclusion criteria were met.3
The Jynneos vaccine’s manufacturer, Bavarian Nordic, said the immunization was available for commercial purchase in the United States. Health care providers can order the vaccine through wholesalers and distribution partners, making it accessible at pharmacies, physician offices, and public health clinics the company said.3
