On Wednesday, the World Health Organization (WHO) declared a global health emergency after a new strain of mpox, formerly known as monkeypox, killed at least 450 people in the Democratic Republic of Congo. The highly contagious disease is now spreading across parts of Central and East Africa.

A day later, Sweden's public health agency announced that it had confirmed the first known case of the new strain outside of Africa, prompting warnings that a "coordinated international response is essential" to stop the spread of mpox, WHO Director-General Tedros Adhanom Ghebreyesus said. Wednesday marks the second time in just over two years that the WHO has declared mpox as a global emergency.