Sweden on Thursday reported a case of a contagious form of mpox currently spreading around central and eastern Africa. The Swedish case marks the first known infection of that strain outside of Africa.

The development comes one day after the World Health Organization declared mpox a global public health emergency after an outbreak in the Democratic Republic of Congo spread to at least 12 other countries in the region.

"It's clear that a coordinated international response is essential to stop these outbreaks and save lives," WHO Director General Tedros Adhanom Ghebreyesus said Wednesday.

The international vaccine group Gavi says it has up to $500 million to spend on sending vaccines to affected countries in Africa, Reuters reported Thursday.

"The money for the vaccines is ready to be tapped into," Gavi CEO Sania Nishtar said.

There may be a delay, however, because the WHO must first approve the vaccines, which the agency said it hoped to do by September.

"With the growing spread of the virus, we're scaling up further through coordinated international action to support countries [to] bring the outbreaks to an end," WHO Regional Director for Africa Matshidiso Moeti said in a Wednesday statement.

This is the second time in two years that the WHO has declared mpox a global public health emergency.

The United Nations health agency made the same declaration in 2022, when the disease was still called monkeypox. Back then, the global outbreak impacted nearly 100,000 people around the world, especially gay and bisexual men.

According to the WHO, there have been more than 14,000 mpox cases and 524 deaths in Africa this year. The Africa Centers for Disease Control and Prevention said that cases were up 160% and deaths have increased by 19% compared with the same period last year.

This version of mpox — known as mpox clade 1b — is different from the version in the 2022 outbreak, which is known as mpox clade 2. Health experts say the clade 1 virus, and its new offshoot clade 1b, can cause a more severe illness than clade 2.

Scientists first identified mpox in 1958. Unlike COVID-19, mpox is not airborne and tends to require close contact — like contact with the skin or fluids of an infected person — to spread.

The disease causes flu-like symptoms such as fever and chills, as well as a rash with painful lesions. Symptoms tend to last for about two to four weeks, according to the Cleveland Clinic, and they often go away on their own.

Some information in this report came from Reuters and The Associated Press.