After weeks of battling Ebola, a North Carolina missionary is thankful for her fight to survive the deadly virus.  

Nancy Writebol and her husband, David, held a news conference Wednesday at the SIM USA charity's campus south of Charlotte. 

Writebol, who contracted the deadly disease during the outbreak in West Africa, thanked her medical team, family and those who prayed for her.

Ebola Americans

'This is God’s story, God is writing this,' Nancy Writebol told a news conference Wednesday in South Carolina after recovering from contracting the Ebola virus in Liberia. Writebol and husband David held a news conference at the SIM USA charity's campus south of Charlotte. (Bob Leverone/Associated Press)

"This is God’s story. God is writing this," Writebol said.

On learning of her Ebola diagnosis after initial treatment for malaria, she told her husband, "It’s going to be OK."

Writebol said she never feared being in Liberia, despite some dark days.

"There were many mornings when I woke up and thought, 'I'm alive!' And there were mornings when I thought, 'I don't think I'm going to make it any more.' "

The Writebols left their home last year for missionary work at a clinic in Liberia, where Nancy Writebol's duties included disinfecting staff entering or leaving the Ebola treatment area. After she was infected, Writebol, 59, was flown to the United States and kept in isolation at Emory University Hospital in Atlanta.

She was released Aug. 19 and has been spending time with her husband at an undisclosed location. Her husband was quarantined for a week at the SIM campus before being released.

Ebola hunger

Despite being centred in West Africa, Ebola has become a global threat that requires urgent action, according to the World Health Organization. (Reuters TV)

Writebol said she's often asked what saved her. She listed treatment with the experimental drug ZMapp, supportive care, medical treatment in Liberia and the U.S. and her faith. "My answer to that question is all of the above."

The virus spreads by direct contact with blood or bodily fluids, not through casual contact.

Margaret Chan, director general of the World Health Organization, said Ebola has become a global threat and requires urgent action.

"As of this week, we are reporting 3,500 cases, confirmed and probable cases, in Guinea, Sierra Leone and Liberia. More than 1,900 deaths, and the outbreaks are racing ahead of the control efforts in these countries,"  Chan said Wednesday in Washington.

Last week, there were just over 1,500 fatalities.

The UN health agency also provided an update Wednesday about the outbreak in Nigeria, which was sparked by an infected air traveller in July. WHO said an ill doctor in southern Nigeria exposed dozens of people to the Ebola virus by continuing to treat patients before he died.

"The outbreak of Ebola virus disease in Port Harcourt (Nigeria) has the potential to grow larger and spread faster than the one in Lagos," WHO said in a statement.

"Social mobilization efforts have been stepped up, initially targeting key community and religious leaders. However, civil unrest, security issues, and public fear of Ebola create serious problems that could hamper response operations. Military escorts are needed for movements into the isolation and treatment centre."

Another missionary, Dr. Kent Brantly, 33, was released last month after spending three weeks in an isolation unit at the same hospital. He hasn't spoken yet about his plans, but spent much of his first public appearance pleading for help for countries still struggling with the virus.

The news conference comes one day after the charity announced that an American doctor treating obstetrics patients at its hospital in Monrovia, Liberia, has tested positive for Ebola.

The president of a missionary group says a third American who has fallen ill with the Ebola virus decided to return to Liberia after the other two people became ill.

SIM president Bruce Johnson told reporters Wednesday that Dr. Rick Sacra returned to Liberia about a month ago after Writebol and Brantly fell ill.

British man recovers from Ebola

Johnson says the 51-year-old Sacra lives in the Boston area. He adds it's not known whether Sacra will return to the U.S. for treatment.

Meanwhile, a British man infected with Ebola while working as a volunteer nurse in Sierra Leone has been discharged from hospital in London.

William Pooley, 29, was treated in a special isolation unit and also received ZMapp.

"I was very lucky in several ways," he said. "Firstly in the standard of care that I received, which is a world apart from
what people are receiving in West Africa at the moment despite lot of organizations' best efforts.
 
"The other difference to a lot of Ebola cases [is] that my symptoms never progressed to the worst stages of the disease. I had some unpleasant symptoms but nothing compared to some of the worst of the disease."

With files from The Associated Press and Reuters