The two nations saw only 18 cases last week from just a few hot spots.
Evidence includes a gene signature match from the woman's blood and Ebola RNA in the man's semen.
Lab-confirmed cases held steady last week, while some response statistics show reason for concern.
The plan seeks to cut cases, limit cases to coastal areas, and boost contact tracing and surveillance.
United Nations (UN) Secretary-General Ban Ki-moon on Apr 25 appointed Peter Jan Graaff to lead the UN Mission for Ebola Emergency Response (UNMEER), taking the place of Ismail Ould Cheikh Ahmed of Mauritania, who had held the position since late December. Ould Cheikh Ahmed succeeded UNMEER's first chief, Anthony Banbury.
Separate reports describe using TKM-Ebola and convalescent serum, as well as minimal virus changes.
Also, an animal study shows promise for TKM-Ebola, and another notes long-term effects of the disease.
A possible risk of Ebola transmission from survivors' semen prompted the CDC to revise its advice.
The World Bank says it will provide at least $650 million to help West Africa recover.
Also ahead of economic talks, Oxfam said $1.7 billion is needed to rebuild health systems, and the World Bank shared employment data.
