The Ebola patient in Nigeria, the Ugandan-born wife of a Swiss diplomat based in Abuja, did not travel to Democratic Republic of Congo, the Swiss government said in a statement to Reuters on Friday, contradicting accounts from Uganda.

The Swiss Federal Department of Foreign Affairs had on Thursday told Reuters that the woman, who it identified as a Swiss national, was believed to have contracted Ebola while travelling with her husband in Uganda, where the government says there are no cases.

Ugandan authorities have said the woman who fell ill in Nigeria had travelled to eastern Congo, where the ongoing outbreak was declared in mid-May and has since become the fastest-spreading on record.

But the World Health Organization and Africa's top health agency said on Thursday they had not received confirmed ​information that the woman had travelled to Congo."She and her husband did not travel to the Democratic Republic of the Congo," the Swiss foreign affairs department said on Friday.

Uganda reported 20 Ebola cases in May and June, mostly imported ​from Congo, but the WHO declared the country Ebola-free in August.

Ugandan government spokesperson Alan Kasujja told Reuters on Thursday that Uganda had no Ebola cases and that if it did, it would make that information public.

The case in Nigeria, the country's first Ebola case in more than a decade, means the outbreak has spread to four African countries - Congo, Uganda, Kenya and Nigeria - and it is confirmed to have killed about 4 700 people, according to the Africa Centres for Disease Control and Prevention.