The Ebola virus was introduced into Nigeria on 20 July when an infected Liberian man arrived by aeroplane into Lagos, Africa’s most populous city. The man, who died in hospital 5 days later, set off a chain of transmission that infected a total of 19 people, of whom 7 died.
According to WHO recommendations, the end of an Ebola virus disease outbreak in a country can be declared once 42 days have passed and no new cases have been detected. The 42 days represents twice the maximum incubation period for Ebola (21 days). This 42-day period starts from the last day that any person in the country had contact with a confirmed or probable Ebola case.