The U.S. doctor who contracted Ebola while working on a humanitarian mission in Congo has been released from a hospital in Germany after recovering from the potentially deadly disease.

Dr. Peter Stafford was working with the missionary group Serge in the Congo when he was infected with the virus, the group said. He was evacuated to a hospital in Berlin to receive care on May 20, according to the group. His wife, also a doctor volunteering with Serge, and their four children were also evacuated and quarantined.

Peter Stafford was treated at Charité hospital in Berlin, one of the top hospitals in Europe, where he received "antiviral therapy and additional supportive medical measures during the first week," the hospital said in a statement Saturday. His condition consistently improved over the course of his treatment, the hospital said. 

"The initially high viral load decreased substantially under antiviral treatment and supportive care," Charité said Saturday. "Since May 30, no virus has been detected in the daily follow-up tests. In accordance with internationally accepted criteria-complete absence of symptoms for more than 72 hours and negative virus detection in repeated PCR tests-the competent public health authority lifted the isolation order today at 12:00 PM."

While quarantined, neither Stafford's wife, Rebekah, nor their four children ever developed symptoms of Ebola, according to Charité. He was reunited with his five family members on Saturday.

"We are very pleased with the successful course of treatment and consider this a significant therapeutic success," Leif Erik Sander, director of the Department of Infectious Diseases and Critical Care Medicine at Charité, said in a statement. "On behalf of the entire team, we thank all participating specialties and departments that made the successful treatment in the specialized isolation unit possible."

The Bundibugyo ebolavirus outbreak in Congo, which has spread to neighboring Uganda, is causing serious concern among health officials and is likely larger than what has officially been reported, they have warned. The Bundibugyo strain is significantly less common than the Zaire strain of the virus and has no vaccines or treatment.

There have been 452 confirmed cases and 82 confirmed deaths in the Congo as of Thursday, and 19 confirmed cases and two confirmed deaths in Uganda as of Friday, according to the countries' respective health ministries.

Stafford was exposed to the virus during a surgery at Nyankunde Hospital in Bunia, a city in eastern Congo, Serge previously said. He has worked at the hospital since 2023, according to the group.

"I received first-class care, including experimental therapies currently being trialed for this type of virus," Stafford said in a statement provided by Charité. "Words cannot adequately express my gratitude. Thank you to everyone who made this possible. Our thoughts remain with the people in the Congo who do not have access to such care."

A third doctor working with Serge, Dr. Patrick LaRochelle, was also potentially exposed while working in a Congo hospital. The American was asymptomatic and in quarantine at Bulovka Hospital in Prague, according to Serge's last update on May 24.