LONDON — A Scottish nurse who became critically ill last month — 10 months after recovering from Ebola — has again recovered.

The nurse, Pauline Cafferkey, contracted Ebola last year while doing charity work in Sierra Leone and recovered for the first time in January. Last month, she again fell critically ill from the virus.

She was discharged on Wednesday from the Royal Free Hospital in London, which has Britain’s only high-level isolation ward for the treatment of infectious diseases, the hospital announced on Thursday. She was transferred for additional care to Queen Elizabeth University Hospital in Glasgow.

Ms. Cafferkey was the second person found to have Ebola in Britain.

Ebola can persist for months in certain body tissues that are relatively protected from the immune system, including the eyes and the testes, and much is still unknown about the long-term effects of the virus.