The deadly virus of Ebola could spread worldwide, experts have warned.
The revelation came as infected Liberian passenger Patrick Sawyer brought the virus into Nigeria on a flight to Lagos on 20 July, spreading to the fourth African country. Sawyer died in a Nigerian hospital five days later.
The virus, which first spread in Liberia in January, has also hit Sierra Leone, Guinea and now Nigeria.
Experts fear that the other passengers who flew with Sawyer and might have contracted Ebola, could now spread it around the world.
Professor Hugh Pennington, emeritus professor of bacteriology at the University of Aberdeen, told the Daily Mail: "If the disease gets going in Nigeria, it would be cause for concern.