The spread of mpox in Africa needs to be addressed urgently, the World Health Organization said on Tuesday, as scientists warned separately of a dangerous strain in the Democratic Republic of Congo. "There is a critical need to address the recent surge in mpox cases in Africa," Rosamund Lewis, the WHO's technical lead for mpox, said in a briefing note to journalists. In a separate briefing, John Claude Udahemuka of the University of Rwanda, who has been working on an outbreak in Congo's hard-to-reach South Kivu province, said the strain spreading there - a mutated version of the clade I mpox endemic in Congo for decades - was extremely dangerous. It has fatality rates of around 5% in adults and 10% in children. Mpox is a viral infection that spreads through close contact, causing flu-like symptoms and pus-filled lesions. Most cases are mild but it can kill.