From the story here:
Scientists do not know how the virus hid inside the woman for 13 months before re-emerging in lethal form. However, because she fell ill soon after giving birth, experts believe the immune suppression that normally occurs in pregnancy may have triggered a relapse. ...
A 15-year-old boy, the woman’s oldest son, was hospitalized vomiting blood. He tested positive for Ebola and, despite intensive treatment, died 10 days after his symptoms first appeared. ...
[S]urvivors must be tested for Ebola if they fall ill, even if they lack common Ebola symptoms.
