Nurse Pauline Cafferkey, who was rushed to hospital for a fourth time since her return from Africa, has tested negative for the Ebola virus, NHS Greater Glasgow and Clyde said.
Ms Cafferkey was taken to the Queen Elizabeth University Hospital in Glasgow under police escort on Thursday morning.
She was undergoing "routine monitoring" by the infectious diseases team and remains in a stable condition, NHS Greater Glasgow and Clyde (NHSGGC) said.
The nurse was infected with the Ebola virus while working in Sierra Leone as a volunteer for Save The Children.
On her return from west Africa at the end of 2014, she was quickly struck down and was treated at the Royal Free Hospital in London.
Ms Cafferkey was discharged in January 2015, with doctors saying she had completely recovered and was not infectious in any way.
However, she was readmitted to hospital twice - in October 2015 and February 2016 - after suffering complications linked to the disease, at one stage falling critically ill.
An NHSGGC spokeswoman said: "Pauline Cafferkey was admitted to the Queen Elizabeth University Hospital this morning under the care of the Infectious Diseases Unit.
"Due to Ms Cafferkey's past medical history, appropriate precautionary measures were taken whilst further investigations were carried out.
"We are pleased to report that tests for the Ebola virus are negative.
"She remains in a stable condition in the Queen Elizabeth University Hospital. We want to repeat our previous reassurance that there is no risk to the public.
"We will not be issuing further statements and would ask that Pauline's privacy and right to medical confidentiality be respected."
Last month Ms Cafferkey was cleared of misconduct over her return to the UK with the virus.
She was accused by the Nursing and Midwifery Council of allowing an incorrect temperature to be recorded in a ''chaotic'' screening centre in Heathrow on her return from Sierra Leone in late 2014.
Ms Cafferkey said she would never have knowingly put anyone in danger and an independent panel found three charges against her were not proven and her fitness to practise was not affected.
It ruled her judgment at the airport in December 2014 had been so impaired by the developing illness that she could not be found guilty of misconduct.
Speaking outside the hearing in Edinburgh, Ms Cafferkey's lawyer said she was ''relieved the process is at an end'' and stressed the nurse would have never knowingly placed anyone in danger.
Joyce Cullen said of her client: ''She willingly put her life at risk to travel to Sierra Leone to work as a volunteer helping to treat people suffering from Ebola.
''She and hundreds of other volunteers played a vital role in saving lives, helping to curb the epidemic in extremely challenging circumstances.''
During the Ebola outbreak which swept Guinea, Liberia and Sierra Leone, more than 28,000 cases were reported, resulting in over 11,000 deaths.
The World Health Organisation declared Sierra Leone Ebola-free in March this year.