Hospital staff members walk back into the hospital in Madrid, where Ebola infected Spanish nurse is being treated. (Associated Press)
Spain's Ebola patient remained in serious but stable condition on Monday, with doctors cautiously hopeful she can recover.
Fernando Rodriguez Artalejo, a member of the government committee set up to monitor the case, said every hour that assistant nurse Teresa Romero fights the disease gives her more chance of developing an effective immunity response.
Ms Romero, 44, contracted Ebola after treating a Spanish missionary who fell victim to the disease while in West Africa and died at the Madrid hospital last month.
Antonio Andreu - the director of Madrid's Carlos III hospital, where Ms Romero is being treated - said tests carried out on her on Sunday showed the level of virus had diminished significantly. But he also said on Onda Cero radio that there could be other complications and it is too risky to make predictions.
Mr Andreu said the 15 people who came into contact with Ms Romero and who are being monitored at the hospital have not shown any Ebola symptoms, and he gave October 27 as the date for a possible all-clear for them.
Rodriguez Artalejo said the medical staff now treating Ms Romero will then have to be monitored for 21 days, the disease's incubation period.
Meanwhile, the Health Ministry, which said Spain had obtained a dose of the experimental Ebola drug ZMapp to treat Ms Romero, said it actually has ZMab, another version of the drug.