Story highlights Death toll from an Ebola outbreak in Guinea reaches 70, including 4 in the capital

Doctors have set up isolation facilities in two regions, because there is no cure or vaccine for Ebola

Senegal says it's closing the border with Guinea of prevent spread of Ebola

World Health Organization says no cases of Ebola confirmed outside of Guinea

At least 70 people are reported to have died from Ebola hemorrhagic fever in Guinea, according to a statement from the West African nation's health ministry.

Officials say there are at least 111 suspected cases of the viral disease, which spreads in the blood and shuts down the immune system, causing high fever, headache and muscle pain. The virus is transmitted by contact with the fluids of infected people or animals.

"The priority is to isolate suspected cases," said MSF, which has set up two isolation facilities in the most affected districts, Gueckedou and Macenta, both in southern Guinea.

JUST WATCHED Ebola virus spreads to Guinea capital Replay More Videos ... MUST WATCH Ebola virus spreads to Guinea capital 03:39

Four of the fatalities from the disease are in Conakry, the capital city, which is on the coast.

Genetic analysis of the virus shows that it is closely related to Zaire Ebola virus, which was reported in 2009 in the Democratic Republic of the Congo (formerly Zaire), according to the Centers for Disease Control and Prevention.

Senegal's Interior Ministry decided to close its border with Guinea until further notice to prevent the spread of the disease, according to Senegal's state news agency.

The World Health Organization says that, to date, no confirmed cases of Ebola have been found outside of Guinea, but at least 12 suspected cases are under investigation in neighboring Liberia and Sierra Leone.