Genetics will determine whether a person infected with Ebola dies, scientists claimed today. A new study has found DNA could be the key to tracking the deadly effects of the virus which has ravaged West Africa. The World Health Organisation revealed nearly 5,000 people have died from the disease, which has devastated Guinea, Liberia and Sierra Leone. A team of scientists at Washington University believe their study has identified genetic factors behind the mild-to-deadly range of reactions to the virus.