Zambia has banned the entry of citizens from countries hit by the deadly Ebola virus, which is ravaging nations to the north of the continent, the health ministry said Saturday.

Clinical trials of vaccines for the deadly Ebola virus should soon get underway and will likely be ready for widespread use by early next year, the World Health Organization said Saturday.

Residents of northern Liberia have existed in a state of peril for months as the deadly Ebola epidemic swept through the region. Now they face a new threat as measures to stem the spread of the virus spark fears of starvation.

Guinea on Saturday said it was closing its land borders with Liberia and Sierra Leone in a bid to halt the spread of the deadly Ebola virus which has claimed hundreds of lives in the three west African countries.

"In order to better control contact" with people suspected of carrying the Ebola virus, "Guinea has decided to temporarily close its land borders with Liberia and Sierra Leone," government spokesman Albert Damantang Camara said.

A Saudi man who died while showing symptoms similar to Ebola was not infected with the virus, according to initial test results cited by health authorities on Saturday.

The health ministry announced Wednesday that the man had died of a heart attack.

Health Minister Wael Abou Faour on Saturday urged Lebanese expats who have concerns about getting infected with the deadly Ebola virus or other epidemics to report their fears to the ministry, assuring also that treatment will be provided for them.

"We call on all Lebanese expats in Sierra Leone, Guinea, Nigeria and Liberia who are suspecting that they might have been infected with the Ebola virus or any other epidemic, or those who are seeking treatment, to reach out to the Health Ministry in Beirut through their local embassies,” a statement issued by Abou Faour said.

A Congolese nun who worked with Spanish Catholic missionaries in Liberia has died of Ebola, the charity she worked for said Saturday in Madrid.

Chantal Pascaline died early Saturday "due to Ebola at the Hospital of Saint Joseph of Monrovia" in the Liberian capital, the Hospitaller Brothers of St. John of God said in a statement.

Here are the main epidemics which have broken out over the past century, after the World Health Organisation on Friday designated the killer Ebola ravaging parts of west Africa an international health emergency:

The devastating news didn't make sense to Brazilian Pierre Freitaz. How was it possible that, at age 17, he was infected with HIV if his only boyfriend seemed fit and healthy?

Freitaz confesses he knew little about the virus when he was diagnosed in 2004. He didn't understand the difference between the infection and the disease it caused: AIDS. He was confused by the lack of obvious symptoms.

A Canadian hospital put a patient in isolation Friday after he arrived in the country from Nigeria with symptoms of fever and flu -- possible signs he is infected with Ebola -- local media said.

Nigeria is one of several countries in West Africa that has had confirmed cases of Ebola, in the world's largest ever outbreak of the deadly hemorrhagic fever that has seen nearly 1,000 deaths and more than 1,700 people infected since the beginning of the year.