(CNN) – Nancy Writebol fought for her life against Ebola hemorrhagic fever on Thursday.

While she did, the virus that befell the American missionary, as she worked to save its victims, continued its record outbreak through West Africa.

Ebola has killed more than 650 people, says Doctors Without Borders, a group of medical workers nursing victims through the disease as it runs its course. There is no cure, no vaccine.

The care from medical workers is saving the lives of a little less than half of those taken ill, and Writebol’s family is praying it will hers, too.

Her husband, David, who is with the same mission, is near her, said their son Jeremy, who spoke with CNN’s Chris Cuomo from the United States.

But she is isolated from him, and he has to wear head-to-toe protective clothing similar to a hazmat suit so that he does not contract a disease that starts out with similar symptoms as a strong flu but can end in internal bleeding and death.

“Mom continues in stable condition but it’s very serious, and she’s still fighting,” her son said. “She’s weak, but she’s working through it.”

Prayers and efforts

Back home, in Charlotte, North Carolina, late Wednesday, members of Calvary Church, which sent her on the mission to Liberia, met to pray for her struggle.

Writebol is working with faith-based international charity Samaritan’s Purse. One of her American colleagues, Dr. Kent Brantly, also has taken ill.

U.S. government officials are in ongoing talks to bring them back from Africa, an administration official and a State Department source said on Thursday.

Liberia’s Information Minister Lewis Brown wants them both to live through this. The country needs for more health care workers like them, he said.

“We join the families in prayers that they can come through this and become…shining examples that, if care is taken, one can come out of this.”

A local physician was not so fortunate. Dr. Sheik Humarr Khan fell ill early last week while overseeing Ebola treatment at a Sierra Leone hospital and died days later.

Record death toll

The current death toll that is the highest on record with the World Health Organization and still growing.

“This epidemic is without precedent,” said Bart Janssens, director of operations for Doctors Without Borders, also known as Médecins Sans Frontières. “It’s absolutely not under control, and the situation keeps worsening.”

The rate of infection has slowed in Guinea, but it has increased in neighboring Sierra Leone and Liberia. As infection accelerates, some aid groups are pulling out to protect their own.

Samaritan’s Purse and the missionary group Serving in Mission have recalled all nonessential personnel from Liberia.

The Peace Corps announced Wednesday it is doing the same, removing its 340 volunteers from that country, as well as Sierra Leone and Guinea.

While there are no confirmed cases, a Peace Corps spokeswoman said that two volunteers came into contact with someone who ended up dying from the virus.

Those Americans haven’t shown signs of Ebola but are being isolated just in case, with the spokeswoman saying they can’t return home until they get medical clearance to do so.

Presidents doubling down

The swelling cases have prompted the heads of state of two countries to cancel travel plans on Thursday to direct their full attention toward fighting the outbreak of the virus that has crippled parts of Liberia, Sierra Leone and Guinea and stirred palpable concerns that it will spread around the region and the world.

Liberian President Ellen Johnson Sirleaf and Sierra Leone’s President Ernest Koroma both canceled trips to the United States, and Koroma declared a state of emergency. He announced an action plan to tear down many barriers that international medical workers say they face while fighting disease.

Some residents in affected villages have accused medical workers of bringing the disease into the country and have barricaded their towns or otherwise blocked access to Ebola victims.

“The most challenging” aspect of trying to help people is that “we go into communities where we are not necessarily welcome,” said Monia Sayah, a nurse with Doctors Without Borders.

People don’t want to believe they or their loved ones have Ebola — in part because “they understand now that the survival rate is not very high,” she said.

Koroma said he will deploy police and military to accompany the aid workers.

They will search house to house for the infirm and enforce orders designed to curb the virus’ spread.

American dies in Nigeria

One American, 40-year-old Patrick Sawyer, died in a Nigerian hospital earlier this month — having come from Liberia.

He was in a plane to Lagos, when he became violently ill.

He was planning to go back home to Minnesota to celebrate his daughters’ birthdays, but the disease took his life before he could.

On Monday, the CDC issued an alert warning travelers to avoid hospitals with Ebola patients and funerals for those patients.

The United States is considering raising the alert to discourage “nonessential” travel to those three countries, a spokesman said.

But on Thursday International Air Transport Association issued a calming statement, saying it was not recommending travel restrictions to affected areas. Referring to the WHO, it said travelers there faced “extremely low” risk of contracting Ebola.

As of now, the outbreak has been confined to West Africa. But it could spread via travel, especially since people who have Ebola may not know it. Symptoms usually manifest two to 21 days. Further complicating matters, signs of Ebola include fever, headaches, weakness and vomiting — symptoms that also define many other ailments, from malaria to the flu, that Brown notes often pop up “at this time of year.”

Sawyer, for example, very well could have made it out of the region, perhaps to the United States, before showing symptoms of Ebola; it’s only then that the virus spreads.

“If the situation does not improve fairly quickly, there is a real risk for new countries to be affected,” Janssens said.

Ebola spreads through the transmission of bodily fluids. Those most at risk are loved ones of those infected, as well as health care workers tending to the ill.

Sawyer is believed to have been infected by his ailing sister, who he spent time with in Liberia, according to Brown. Neither likely knew she had Ebola.