Africa's top public health body declared what it termed a "public health emergency of continental security" on Tuesday over an outbreak of mpox that spread from the Democratic Republic of Congo to neighboring countries.

Mpox is transmitted through close contact and causes flu-like symptoms and pus-filled lesions. Most cases are mild but some can kill.

The outbreak in Congo began with the spread of an endemic strain, known as Clade I. But the new variant, known as Clade Ib, appears to spread more easily through routine close contact, particularly among children.

The Africa Centres for Disease Control and Prevention (Africa CDC) warned last week that the viral infection's rate of spread was alarming.

It said that over 15,000 mpox cases and 461 deaths were reported on the continent this year so far, representing a 160% increase from the same period last year.

Mpox has been endemic in parts of Africa for decades after it was first detected in human in the Democratic Republic of Congo in 1970.

A milder version of the virus spread to over a hundred countries in 2022, largely through sexual contact, prompting the World Health Organization (WHO) to declare a public health emergency of international concern, its highest level of alert.

The WHO ended the emergency 10 months later, saying the health crisis had come under control.