Pauline Cafferkey, a British nurse who got infected with Ebola after working as a volunteer in West Africa last year, is now "critically ill" in a London hospital. The nurse had been declared free of the disease for 10 months before being rushed back to the hospital last week due to complications from the virus, according to NBC News.

Cafferkey is being treated in a special isolation unit in the Royal Free Hospital in London, the same medical facility she was interred in during her first confinement due to the deadly virus.

"We are sad to announce that Pauline Cafferkey's condition has deteriorated and she is now critically ill. Pauline is being treated for Ebola in the high level isolation unit at the Royal Free Hospital," the hospital said in a statement.

The 39-year-old nurse had previously stayed in the hospital for almost a month earlier this year, when she was first diagnosed with the disease after arriving back to the U.K. Though she was eventually discharged and declared Ebola-free, tests conducted last week revealed that the virus was still present in her body, reported BBC News.

Though the hospital states that Cafferkey is not a threat to the public, the hospital nonetheless offered vaccinations for those who have had close contact with the nurse. Among the 58 people who were identified to have been in close contact with Cafferkey, 25 have been vaccinated.