The pathogen enters the body through broken skin, the respiratory tract or the mucous membranes in the eyes, nose, mouth, rectum and anus.
The main animal source of the disease hasn’t been identified, but infected rodents are suspected of playing a key part in transmission across parts of Africa.
During the first major outbreak in 2022, the virus mostly spread among communities of gay men.
The new variant appears to be more transmissible, and is reportedly infecting many people without sexual contact. The emergence of a new mutant strain, or clade, is concerning as it indicates the virus is adapting and getting better at spreading from person to person.
What is a global health emergency and why was one declared?
A “public health emergency of international concern” or PHEIC is the WHO’s highest form of alert.
They are declared when diseases are spreading in new or unusual ways, and are aimed at galvanising international co-operation and funding to tackle an outbreak.
The WHO’s declaration follows a similar label from the Africa Centres for Disease Control and Prevention earlier this week.
Speaking after the emergency was declared, WHO chief Tedros Adhanom Ghebreyesus said the potential for further spread within Africa and beyond “is very worrying”.
“A coordinated international response is essential to stop this outbreak and save lives,” he said.
