LONDON, - Scientists have used Ebola disease spread patterns and airline traffic data to predict a 75 percent chance the virus could be imported to France by October 24, and a 50 percent chance it could hit Britain by that date.Those numbers are based on air traffic remaining at full capacity. Assuming an 80 percent reduction in travel to reflect that many airlines are halting flights to affected regions, France's risk is still 25 percent, and Britain's is 15 percent."It's really a lottery," said Derek Gatherer of Britain's Lancaster University, an expert in viruses who has been tracking the epidemic - the worst Ebola outbreak in history.The deadly epidemic has killed more than 3,400 people since it began in West Africa in March and has now started to spread faster, infecting almost 7,200 people so far. Nigeria, Senegal and now the United States - where the first case was diagnosed on Tuesday in a man who flew in from Liberia - have all seen people carrying the Ebola haemorrhagic fever virus, apparently unwittingly, arrive on their shores.France is among countries most likely to be hit next because the worst affected countries - Guinea, Sierra Leone and Liberia - include French speakers and have busy travel routes back, while Britain's Heathrow airport is one of the world's biggest travel hubs.France and Britain have each treated one national who was brought home with the disease and then cured. The scientists' study suggests that more may bring it to Europe not knowing they are infected.