On October 22 the CDC announced that travelers arriving from the Guinea, Liberia, and Sierra Leone will be actively monitored for 21 days following thier last possible date of exposure to the Ebola Virus.  This measure will help public health officials identify anyone who may be infected early in their illness and reduce the chance of spreading the virus to others. 

As of October 20, Senegal and Nigeria have been declared "Ebola-free" by the WHO meaning there have been no new cases for two incubation periods (42 days). 

Countries with widespread Ebola activity are Guinea, Liberia, and Sierra Leone.  Nigeria had 20 localized cases.  Mali has had eight confirmed cases.  Senegal and Spainhave each confirmed one case.  The U.S. has had four cases.