Lagos, Shawwal 10, 1435, Aug 6, 2014, SPA -- Four West African countries are struggling with the worst Ebola outbreak in history, one that has begun to spread to other nations, according to Reuters. Below are some facts regarding the outbreak: - The outbreak has so far killed 932 people - or around 55 percent of those known to have been infected - and sickened hundreds more. The disease emerged in the remote forest regions of Guinea, but has since spread to Liberia, Sierra Leone and Nigeria. - There is no vaccine or cure for Ebola - a hemorrhagic fever with a fatality rate of up to 90 percent that causes symptoms ranging from flu-like pains to internal and external bleeding caused by kidney and liver failure. - Ebola's suspected origin is forest bats and it can be transmitted between humans by touching victims or through bodily fluids. The virus was first identified in 1976 in what is now known as the Democratic Republic of the Congo. - Since 1976, there have been 34 known cases and outbreaks of Ebola, according to the U.S. Centers for Disease Control and Prevention. Before the latest outbreak, the deadliest episode was the first, in 1976, which killed 280 people in Central Africa. - Two American aid workers stricken with Ebola in West Africa are now being treated at an Atlanta hospital. Their conditions improved by varying degrees after they received an experimental drug developed by San Diego-based private biotech firm Mapp Biopharmaceutical Inc. - The World Health Organization said it is considering the implications of making experimental drugs more widely available to patients in Africa. The Mapp drug, ZMapp, is a cocktail of antibodies designed to bind to and inactivate the Ebola virus. Other products in development include antiviral drugs and preventive vaccines. -- SPA 00:03 LOCAL TIME 21:03 GMT www.spa.gov.sa/w