A blood test has revealed that Teresa Romero's immune system has eliminated the virus from her body, according to a statement released by Prime Minister Mariano Rajoy's office late today.
Manuel Cuenca, microbiology director at Madrid's Carlos III health care complex, says a second test in the coming hours is needed to absolutely confirm Romero's recovery.
Romero, 44, had treated two patients who died of Ebola at Carlos III hospital.
The first, Miguel Pajares, contracted the disease in Liberia and died on Aug 12 despite having been treated with the experimental drug ZMapp.