American doctor Kent Brantly and missionary Nancy Writebol have been released from Emory University Hospital in Atlanta after recovering from the Ebola virus infections, and doctors said the hospital team learned much about disease treatment through caring for the two patients.

The Emory team will be sending specific guidelines to health-care providers in Africa about the importance of fluid and electrolyte replacement and information about clotting abnormalities to help them treat other patients, said Bruce Ribner, medical director of Emory’s Infectious Disease Unit, who led the team that treated the two Americans.

Brantly was released Thursday and Writebol was discharged Tuesday. They underwent rigorous treatment and testing to ensure that the virus was no longer present in their systems.

“The medical staff is confident that the discharge of both of these patients poses no public threat,” Ribner said. They were only cleared for release after blood tests by the Centers for Disease Control and Prevention showed the absence of virus for two consecutive days.

The two received an experimental treatment called ZMapp while they were still in Liberia, where they contracted Ebola while caring for infected patients. Brantly, who was working with Samaritan’s Purse, a Christian humanitarian organization, also received a unit of blood from a 14-year-old boy who had survived an Ebola infection.

Although the use of experimental treatments was recently endorsed as ethical by the World Health Organization, Ribner said doctors can’t say for sure whether the treatment made a difference for either Writebol or Brantly.

“Honestly, I don’t know,” he said. “They are the first individuals to receive this agent. We do not know whether it helped them, whether it made no difference, or if it delayed their recovery.”

“The critical difference in caring for the two patients in an American hospital was the infrastructure available for their care,” he added.

“Even though the people taking care of infected people in Africa are good and skilled, they don’t have this kind of monitoring equipment--they’re almost flying blind,” said Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases at the National Institutes of Health.

A third patient, a Spanish priest who received Zmapp, died. Three Liberian health workers also received the treatment, which includes manmade antibodies against the virus. The manufacturer, Mapp Biopharmaceutical of San Diego, has said there is no more of the drug remaining.

Since Ebola virus was first identified in 1976, no previous outbreak has been as large or persistent as the current epidemic, which has killed 1,350 people in four African nations, according to the WHO.

“Today is a miraculous day,” Brantly said Thursday at an Emory news conference. “I am thrilled to be alive, to be well and to be reunited with my family.” He hugged his wife and each member of nearly two dozen doctors and nurses gathered behind the podium.

The Ebola epidemic over time

The Texas doctor was flown back to the United States from Liberia in a special transport plane that included an isolation unit and arrived at Emory on Aug. 2. Days later, Writebol, a missionary from Charlotte, N.C., was flown to Atlanta in the same “air ambulance.”

Writebol was working at a hospital in Liberia with her husband through a different global ministry group, SIM. She did not appear at the news conference. But her husband David Writebol, in a statement, said that his wife hoped for privacy to recover her strength.

“Nancy is free of the virus, but the lingering effects of the battle have left her in a significantly weakened condition,” he said. “Thus, we decided it would be best to leave the hospital privately to be able to give her the rest and recuperation she needs at this time.”

The recovery of the two is in stark contrast to the ongoing struggle to deal with the outbreak in West Africa, where health systems lack even basic treatment tools that could save lives.

Brantly urged governments to do everything possible to end the epidemic.

“I’m glad for any attention my sickness has attracted to the plight of West Africa in the midst of this epidemic,” Brantly said. “Encourage those in positions of leadership and influence to do everything possible to bring this Ebola outbreak to an end.”

In a statement, CDC Director Tom Frieden said organizations must re-commit to do all they can to boost survival chances.

“This outbreak is unprecedented, and it’s likely to get worse before it gets better,” Frieden said. “We must respond in an unprecedented way to stop the outbreak as soon as possible.”

Brantly and Writebol are now considered immune to the Zaire strain of the virus, which is present in this outbreak. Assuming the two make a normal recovery, they would probably not be at risk for infection if they resumed caring for patients during this outbreak, Ribner said. They would be less protected against the four other strains.

For some men, Ebola virus can remain in semen for up to three months, so there is a theoretical possibility of spread through sexual contact in men who have recovered, Ribner said in a later email. Male survivors should avoid having sex for three months or use condoms, he said. After past Ebola outbreaks, however, follow-up studies of patients who have recovered from Ebola and their contacts found no evidence that the virus was transmitted from a recovered patient to their close contacts, he said.

Terence McCoy contributed to this article.