Risk of global Mpox outbreak rises as virulent strain spreads in Congo

By Thomas Mulier

A more virulent strain of Mpox has been transmitted sexually for the first time in the Democratic Republic of Congo, posing the risk of more serious outbreaks of the disease globally, the World Health Organization warned.
 

A Belgian resident with connections to the DRC and his sexual contacts tested positive for a strain of Mpox, known as Clade 1, which has a fatality rate of about 10% and is the more serious of the two types of the virus. The outbreak of sexually transmitted Mpox cases that began globally last year are from the less severe Clade 2 type of the virus. 

This first documented sexual transmission of this strain is unusual, and there’s a risk of Mpox outbreaks spreading to other countries with potentially more severe consequences than the one which has been affecting the world since 2022, the WHO said.

It comes amid a wider spread of Mpox throughout the DRC. More than 12,500 people have been infected and 581 deaths are thought to have been caused by the virus in the country between January and the start of November, the WHO said. That’s the highest number of cases reported since human-to-human transmission of Mpox was detected in the 1970s. The disease was formerly known as monkeypox.

A cousin of the smallpox virus, Mpox has mostly been confined to developing countries for years, but spread across Europe and the US last year. The smallpox vaccine Imvanex has shown effectiveness against Mpox. The disease now is showing up in regions in Congo where it wasn’t before, including in the capital Kinshasa. 

The pathogen typically causes flu-like symptoms, followed by a rash that often starts on the face and spreads down the belly. The illness often lasts for two weeks to a month, and can be deadly. 

A large proportion of cases have been among men who’ve had sex with men, and many have occurred within sexual networks, though anyone can contract the disease. For those who also have untreated HIV infection, there is particular risk. 

In May, the WHO declared that Mpox was no longer a global health emergency.