As a Liberian man diagnosed with Ebola was fighting to survive Sunday in a Texas hospital, his worried family members and others who were in contact with him said they are being ostracized by the local Liberian community, which is struggling to cope with fear, isolation and the stigma associated with the deadly disease.

Thomas Eric Duncan, who traveled to Dallas from Liberia more than a week ago after coming in contact with Ebola in the West African country, was in critical condition in an isolated hospital ward and “fighting for his life,” Tom Frieden, director of the U.S. Centers for Disease Control and Prevention, said Sunday.

“We understand that his situation has taken a turn for the worse,” he said.

Frieden said he does not believe that Duncan has received any experimental medicines that have been used to treat Ebola. And he would not comment on whether another type of experimental treatment — convalescent serum made from the blood of Ebola survivors — is being used to treat Duncan, referring questions to the hospital caring for him. A spokeswoman for Texas Health Presbyterian Hospital in Dallas did not respond to requests for comment.

Such serum was administered to two American doctors who contracted Ebola while in West Africa. The physicians, as well as another American who was infected with Ebola, also were given experimental drugs and survived. The supply of at least one of the drugs, ZMapp, has been exhausted, and federal officials say it will take time to make more.

Ebola’s catastrophic effect on the body

Still, Duncan’s family members question why experimental Ebola treatments have not been used to treat Duncan, who one family member said is attached to a ventilator at the Dallas hospital.

“We want him to live,” said Mawhen Jallah, 28, the daughter of Duncan’s girlfriend, Louise Troh. “So we want the drug the other people used to get saved if they have it.”

Troh, with whom Duncan stayed for eight days before going to the hospital, said, “We are praying for our loved one.”

Six days after the first U.S. case was diagnosed, fear has raced across the Liberian community here. Public health officials are monitoring as many as 49 people who may have had contact with Duncan, whose flight landed in Dallas on Sept. 20. Four people, including Troh, who were close to him have been ordered to remain in isolation for the 21-day incubation period to help prevent the disease from spreading. CDC officials visit daily to monitor their temperatures for fever. None of them have developed symptoms, health officials said.

As they wait for any signs of illness, family members say their lives have been destroyed by rampant fear of the deadly disease.

“This whole Ebola thing — this virus is tearing people apart,” Jallah said. “Since the whole thing occurred, nobody has come to visit.”

On Saturday night, Jallah sat alone with her two children in the dim light of her garden apartment in Dallas, in self-imposed isolation.

Although CDC officials have cleared her, saying it is unlikely she contracted Ebola when she visited her mother’s apartment last week to welcome the man she calls her stepfather, she said she has been shunned.

Jallah said she did not touch Duncan when she greeted him. She said he was sitting in a chair as she said hello from the door of her mother’s bedroom. But she said people do not understand that it is nearly impossible to contract Ebola without touching the bodily fluids of a symptomatic person.

Jallah’s mother has been ordered into isolation by Dallas health officials. Troh was moved Friday from her apartment to an undisclosed house in Dallas, where she remains with her 13-year-old son, Duncan’s cousin and another 20-year-old man. Each had lived in Troh’s apartment, where Duncan stayed.

Troh’s other daughter, Youngor Jallah, 35, who cared for Duncan before calling the ambulance to get him, was told Sunday by CDC officials that she no longer has to isolate herself and her family.

“They came today to say it is okay if I want to go out,” she said.

But Youngor said she feels that people outside her apartment do not want her to come close. Last week, a neighbor standing outside Youngor’s home pointed a finger at her door.

“That is the Ebola family there,” the woman said.

Mawhen Jallah, who lives several miles from her sister, said that last week her daughter’s babysitter, a friend, called to demand that she remove the 2-year-old girl from her home day care.

“My friend said, ‘I don’t want for your daughter to be here until everything is over,’ ” Mawhen said. “That broke my heart. But I cannot do anything, because I know everybody is afraid.”

She said that people have posted sharp comments on Facebook about the family and that others have whispered, refusing to come close, fracturing a close-knit community of Liberians who had traveled here from a war-torn country to seek refuge.

Troh and her family left Liberia in the early 1990s, in the midst of a civil war that would eventually devastate that country for 14 years.

It was in neighboring Ivory Coast where Troh met Duncan.

“We all lived in the same community,” said Princes Duo, who considers Troh to be like a mother. “I guess he saw her and he loved her. She’s a beautiful woman.”

In 1995, Troh and Duncan had a son, Kasiah Eric Duncan. Three years later, Troh moved to Boston, leaving her children behind.

A civil war in Ivory Coast forced the remaining members of the family to move again, to Guinea. Kasiah, Youngor and, later, Mawhen joined their mother in the United States in 2005 and 2006. By then she was living in Dallas, with another son, Timothy Wayne, now 13 years old.

Troh’s two older sons, Dwana and Emen, still live in Liberia. Another daughter, Kebbeh Jallah, died with her baby in Monrovia, Liberia’s capital, in February after a Caesarean section to deliver her child failed.

Troh has never returned to Liberia and until this year had not seen Duncan since they parted ways in Ivory Coast many years ago. That country’s civil war forced many Liberians back home, and Duncan went with them.

Before he boarded that flight to Dallas, Duncan worked as a private driver for the manager of a Liberian customs clearance agent, but he quit abruptly just before he departed.

Duncan’s arrival in the United States in September was months after he had originally planned.

He had hoped to get his visa approved so he could attend his son’s high school graduation in June.

By the time his visa was approved in September, the Ebola outbreak in Liberia had exploded. Liberia accounts for more than half of the more than 3,400 Ebola deaths in West Africa, according to the World Health Organization.

Neighbors in Liberia said Duncan contracted Ebola while helping to carry a sick, pregnant woman to a hospital. Hours later the woman died.

Mawhen Jallah’s head was covered in a pink scarf Saturday as she curled up barefoot on a brown leather sofa. She picked up her cellphone and called the hospital where her “stepfather” was being treated. “Hello,” she said, “can I speak with Eric Duncan?”

A voice finally answered: “He is in critical condition.”

“Is he taking any drugs for the viral?” Mawhen asked.

“I cannot talk about that,” the hospital worker said.

She hung up the phone. She is worried about Duncan. She also worries about her family members in Liberia. “It is hard to sleep,” she said. “I keep the TV on all night, watching the news. I am crying all night. . . . Our people are suffering, dying every day. We experienced war before, but this type of virus we haven’t experienced before. We are asking God for protection.”

Sullivan reported from Washington.