A dangerous strain of mpox that is killing children and causing miscarriages in the Democratic Republic of the Congo is the most transmissible yet and could spread internationally, scientists have warned.

The virus appears to be spreading from person to person via both sexual and non-sexual contact, in places ranging from brothels to schools.

Hundreds of people with the disease, formerly known as monkeypox, have attended hospital in the mining town of Kamituga, South Kivu province, in what is likely to be the “tip of the iceberg” of a larger outbreak, doctors say.

The new DRC outbreak is a mutated form of clade I mpox. Doctors report a fatality rate of about 5% in adults and 10% in children, as well as high rates of miscarriages among pregnant women.