Throughout the course of the year, the Democratic Republic of the Congo (DRC) has recorded a growing outbreak of mpox cases linked to sexual transmission, the World Health Organization (WHO) said late last week.
This is the country's first outbreak defined by sexual transmission, with several early documented cases seen in sex workers. The outbreak likely began with a Belgian man who traveled to the DRC in March and tested positive for the disease shortly after arriving in the country.
The man reported visiting several underground sex clubs for men who have sex with men (MSM) during his trip, even when he was symptomatic. A total of 27 contacts of the man were identified, and 6 were tested for mpox, with 5 sexual contacts testing positive.
The initial cluster of cases is the first documented sexual transmission of mpox clade 1. It is also the first described transmission of mpox clade 1 among men who have sex with men. There are two clades of mpox, with clade 1, the Congo Basin clade, known to be more virulent and deadly, with case-fatality rates of up to 10%.
Last year, the global mpox outbreak among primary MSM outside of Africa was caused by clade 2, which is rarely fatal. That outbreak caused roughly 91,000 cases, the vast majority sexually transmitted.
Case-fatality rate of 4.6%
From January 1 through November 12, 2023, a total of 12 569 suspected mpox cases, including 581 suspected mpox deaths (case-fatality rate, 4.6%), have been reported in 85% of DRC provinces.
This is the highest number of annual cases ever reported.
"This is the highest number of annual cases ever reported, with new cases in geographic areas that had previously not reported mpox, including Kinshasa, Lualaba, and South Kivu," the WHO said. "Cases with travel history to endemic provinces have been driving chains of human-to-human transmission in non-affected provinces."
In war-torn South Kivu, 80 suspected and 34 confirmed cases—including 20 involving sex workers—have been reported.
Doctors and virologists over the weekend told news agencies that what is happening in the DRC could be happening across Africa, with the more deadly clade 1 virus now being spread sexually. Homosexuality is punished by law in many nations, forcing MSM to operate covertly and underreport illness.
So far the DRC has received no doses of Jynneos, the mpox vaccine that has contributed to far fewer cases in North America and elsewhere in 2023.
Global outbreak slows
Over the weekend the WHO also posted its monthly global mpox situation report, noting that low level transmission continues in Europe and the Americas, while greater transmission is under way in the Western Pacific and Southeast Asia.
In the global outbreak that began last spring in the United Kingdom, a total of 91,788 lab-confirmed cases and 167 deaths have been reported. In October, a total of 668 new cases were reported, a 23% decline from the number of new cases reported during the previous month.
The countries with the most cases remain the United States, Brazil, Spain, France, Colombia, Mexico, the United Kingdom, Peru, Germany, and China.
