Ebola outbreak 'pretty much contained' in Senegal and Nigeria WHO says two of the five countries affected by the world’s worst-ever Ebola outbreak, Senegal and Nigeria, are managing to halt the spread of the disease. In a statement, the organization said only one case has been reported in Senegal and all contacts with the patient have now completed a 21-day follow up, the incubation period of the disease, with no further cases of the virus found. In Nigeria, the number of cases has been cut from 21 to 20 after a suspected case was ruled out and 696 contacts have completed the 21-day follow-up. Three people are still being monitored in Lagos and 175 in Port Harcourt. NEWS24