The World Health Organization (WHO) expressed concern on Friday, December 15, about the risks of international spread of the epidemic of monkeypox, also called mpox, which is spreading in the Democratic Republic of Congo (DRC) and whose sexual transmission is accelerating.

“We are concerned that there is international transmission” from the DRC, Dr. Rosamund Lewis, a WHO mpox specialist, said at a press briefing in Geneva. “The epidemic is spreading rapidly in the country” which this year reported “more than 13,000 suspected cases”, “more than twice the number of cases reported in previous years”, and among them “more than 600 deaths,” she announced.

The WHO had already sounded the alert at the end of November on this epidemic in the DRC, carried by variant 1 of the virus, and announced the sending of an evaluation mission. “The demographic picture in the newly infected areas is therefore concerning because this is the first time that we have seen that the mpox virus affects more women than men,” noted Dr. Lewis.

Outbreaks of the mpox variant 2b had been observed, starting in May 2022, in Europe and the United States, outside the dozen countries in central and west Africa where the disease has long been endemic, pushing WHO to declare the maximum alert level on July 23, 2022.

On May 11, the WHO lifted the alert, but called for continued vigilance. The epidemic spread primarily through sexual relations between men. Since May 2022, more than 92,000 cases have been reported in 117 countries, according to the WHO.

Sexual transmission

Recently, cases reported to WHO have increased again, from around 100 per month from June to August to “more than 1,000 per month” today, Dr. Lewis said, reporting outbreaks of cases in Asia, notably in Japan, Vietnam, China and Indonesia. Cambodia reported its first case this week. Dr. Lewis announced that the organization had been informed of a suspected outbreak on a cruise ship that sailed in Southeast Asia, but lacked information.

The current epidemic in the DRC worries the WHO because it is spreading to areas previously considered spared by mpox, including Kinshasa, Lualaba and South Kivu. And because this is the first time that sexual transmission among patients with variant 1 has been observed, recalled Dr. Lewis. The WHO is also concerned about the level of danger of the variant (also called “clade” by the WHO) circulating in the DRC.

“What concerns us about clade 1 is that it has a higher level of severity, a higher level of mortality,” said Maria Van Kerkhove, acting director of pandemic preparedness at the WHO, during another press conference at the organization’s headquarters.