ATLANTA – The husband of the second American aid worker who was recently diagnosed with Ebola says the patient is weak but showing signs of improvement.

The president of the aid group SIM USA said Tuesday that Nancy Writebol’s husband described her condition as progressing. Bruce Johnson says he spoke with David Writebol, who said Nancy stood and got on a plane in Liberia with assistance to head to Atlanta for treatment. When she arrived Tuesday, she was wheeled in a stretcher.

David Writebol, still in Liberia, says the family was considering funeral arrangements but now feels cautiously optimistic. He praised her treatment in Liberia.

SIM says it’s working to bring David Writebol home.

Johnson says SIM has spent nearly $1 million since the diagnoses of Nancy Writebol and the first American to be brought back, Dr. Kent Brantly, who works for Samaritan’s Purse. Johnson says that group has spent more than $1 million.

Nancy Writebol, 59, was taken from Monrovia, Liberia, to Emory University Hospital, just downhill from the U.S. Centers for Disease Control and Prevention in Atlanta. The plane made a refueling stop in Bangor, Maine.

She arrived two days after Brantly, a doctor with whom she had worked in Liberia and who also contracted Ebola.

The differences were stark in how they went from the ambulance to Emory, which has a highly specialized isolation unit. While Brantly, 33, was able to walk with assistance into the hospital, Writebol – covered from head to toe in a protective suit – was wheeled in on a stretcher.

Still, she was described as showing signs of improvement.

“A week ago we were thinking about making funeral arrangements for Nancy,” her husband said in a statement read by the president of SIM USA, the aid group with which she was working in Liberia. “Now we have a real reason to be hopeful.”

Brantly and Writebol were both infected despite taking precautions as they treated Ebola patients in West Africa, where the virus has been spreading faster than governments can contain it, killing nearly 900 people so far.

Each patient is being given an experimental treatment that has never been tested on humans. The treatment, called ZMapp, was developed with U.S. military funding by a San Diego company, using antibodies harvested from lab animals that had been injected with parts of the Ebola virus. Tobacco plants in Kentucky are being used to make the treatment.

It’s impossible to know whether the drug saved these workers, CDC Director Tom Frieden emphasized. “Every medicine has risks and benefits,” he said to reporters at a health symposium in Kentucky. “Until we do a study, we don’t know if it helps, if it hurts, or if it doesn’t make any difference.”

If the treatment works, it could create pressure to speed through testing and production to help contain the disease in Africa.

There is no vaccine or specific treatment for Ebola, but several are under development, including ZMapp, made by Mapp Biopharmaceutical Inc. It works by boosting the immune system’s efforts to fight the virus. The U.S. Defense Threat Reduction Agency announced last month that it is providing more funding to speed the drug’s development.

Brantly and Writebol were working at a missionary clinic outside Liberia’s capital.

David Writebol said in his statement that his wife was able to stand up and, with assistance, to get on the plane in Liberia. Before the flight, she ate some yogurt, he said.

Ebola is spread by close contact with blood and other bodily fluids, and Writebol’s duties included disinfecting doctors and nurses entering or leaving the Ebola treatment area.

Writebol and Brantly will be sealed off from anyone who isn’t wearing protective gear. Dr. Bruce Ribner, who will treat them, said their families can speak with them through a plate-glass window. On Tuesday, Amber Brantly said in a statement that she has been able to see her husband every day.