Scientists have claimed the Ebola virus could reach the UK and France by the end of the month.
Following an analysis of disease spread patterns and airline traffic data, experts have predicted there is a 75 per cent chance the virus could be imported to France by October 24, while there is a 50 per cent chance it could have also hit Britain.
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.
The estimates have been based on air traffic remaining at full capacity. An 80 per cent reduction in travel however would see France's risk remain at 25 per cent, while Britain's risk would still be at 15 per cent.
See the Ebola outbreak mapped
See the Ebola outbreak mapped
1/7 25 March 2014
This outbreak of the Ebola virus first emerged in the Guéckédou region of Guinea, at a crossroads with both Liberia and Sierra Leone
2/7 31 March
On 31 March the WHO confirmed the outbreak was now international, spreading first into Liberia's northern-most Lofa region
3/7 27 May
The virus spread to Sierra Leone at the end of May - just as agencies were hoping the worst was over
4/7 27 July
In Sierra Leone the virus boomed, and then it spread to Nigeria when the Liberian diplomat Patrick Sawyer flew from Monrovia to Lagos
5/7 9 August
The Nigeria cases sparked fears around the world, and there have now been deaths in Spain and Saudi Arabia involving people who had travelled to West Africa. The numbers of cases continue to rise
6/7 17-20 September
In mid-September, Senegal confirmed its first case linked to the Ebola outbreak, a development the WHO described as a top priority emergency. Numbers of cases continued to grow exponentially in Guinea, Sierra Leone and Liberia, as experts warned they could number one million by January if not contained
7/7 8 October
Two cases of Ebola have now been reported in the US and Europe - the first times the virus has been contracted among health workers outside Africa
Nigeria, Senegal and the US, 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 and Britain have each treated one national who was brought home with the disease before being cured.
The scientists' study suggests that more may bring it to Europe not knowing they are infected.
France is believed to be among the 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.
Heathrow airport meanwhile is one of the world's biggest travel hubs.
Belgium has a 40 per cent chance of seeing the disease imported, while Spain and Switzerland have lower risks of 14 per cent each, according to the study first published in the journal PLoS Current Outbreaks. The study is also being updated at MoBS Lab.
The World Health Organisation (WHO) has not placed any restrictions on travel and has encouraged airlines to keep flying to the worst-hit countries. British Airways and Emirates airlines have suspended some flights.
But Alex Vespignani, a professor at the Laboratory for the Modeling of Biological and Socio-Technical Systems at Northeastern University in Boston who led the research, said the risks change every day the epidemic continues.
He told Reuters: "This is not a deterministic list, it's about probabilities - but those probabilities are growing for everyone.
"It's just a matter of who gets lucky and who gets unlucky."
The latest calculations used data from October 1.
"Air traffic is the driver," Mr Vespignani said. "But there are also differences in connections with the affected countries (Guinea, Liberia and Sierra Leone), as well as different numbers of cases in these three countries - so depending on that, the probability numbers change."
Additional reporting by Reuters