Ebola cases in DRC and Uganda more than doubled in three days. The analysis: late detection catching up to weeks of silent spread, plus a PHEIC and an American case.

Some 88 people have died from the highly contagious haemorrhagic fever in the DR Congo, with one death in Uganda, and at least 336 suspected cases.

An Ebola outbreak in the Democratic Republic of the Congo and Uganda constitutes a "public health emergency of international concern," the World Health Organization said.

Ebola likely spread weeks before health officials knew about cases.