Kenya is closing its borders to travelers from Guinea, Liberia and Sierra Leone, the three countries worst hit by the Ebola outbreak, the government said Saturday.

Kenya Airways also announced that it would suspend its flights to Freetown and Monrovia when the government travel bar on passengers comes into effect on Wednesday.

Nigeria on Saturday said it has trained 800 volunteers to fight Ebola as fears rose that the worst-ever outbreak of the deadly disease could spread across Africa's most populous nation.

Authorities in Nigeria's megacity Lagos last week appealed for volunteers to make up for a shortage of medical personnel because of a six-week doctors' strike over pay.

A woman who fell ill at an immigration facility centre in Scotland is being tested for the Ebola virus, health officials said Friday.

It is thought to be "highly unlikely" that the woman, who British media reported is from Sierra Leone, would test positive, a Lanarkshire health authority spokesman said.

The Ebola outbreak that has killed more than 1,100 people in West Africa could last another six months, the Doctors Without Borders charity group said Friday. One aid worker acknowledged that the true death toll is still unknown.

New figures released by the World Health Organization showed that Liberia has recorded more Ebola deaths — 413 — than any of the other affected countries.

Police arrested seven people in northwest China allegedly involved in a scheme that forced school children to donate blood, state media reported.

The arrested are the deputy chief of a blood centre operated by a company in Gansu province, whose surname was given as Huang, and six jobless men, the official Xinhua news agency reported late Friday.

The United Nations is to step up food aid to reach up to a million people affected by the Ebola outbreak wreaking havoc in west Africa, the World Food Program (WFP) said Friday.

With states of emergency and severe restrictions on movement imposed in the three worst-hit countries, Guinea, Liberia and Sierra Leone, the U.N. agency is bringing in its own aircraft to transport its personnel.

There is evidence the numbers of dead and sickened by Ebola in West Africa may "vastly underestimate the magnitude of the outbreak," the World Health Organization said Thursday. The U.N. health agency said it was prepared for the crisis to continue for months.

With more than 1,060 deaths and 1,975 sickened, the Ebola outbreak is already the deadliest ever.

A cholera outbreak in Ghana's capital has reached "staggering" levels, an official said Friday, blaming poor sanitation and overcrowded health facilities for the rapid spread of the disease. 

Cholera has killed more than 40 people in Accra since June and infected 3,100 others, according to the Ghana Health Service.

It's an eye-catching angle in the story of an experimental treatment for Ebola: The drug comes from tobacco plants that were turned into living pharmaceutical factories.

Using plants this way — sometimes called "pharming" — can produce complex and valuable proteins for medicines. That approach, studied for about 20 years, hasn't caught on widely in the pharmaceutical industry.

Facebook founder Mark Zuckerberg has become the latest celebrity to be doused by a bucket of ice-cold water -- and now he wants Bill Gates to follow suit.

Aimed at raising awareness and cash for the fight against Lou Gehrig's disease, the Ice Bucket Challenge has become a viral craze in the United States in recent weeks.