While expressing such confidence about the American effort, the director, Dr. Thomas R. Frieden, said on the CNN program "State of the Union" that in Africa, "the virus is spreading so fast that it's hard to keep up."
Frieden said that the condition of the patient in Dallas, a Liberian man named Thomas E. Duncan, was "quite critical," having been changed on Saturday from serious. "We understand that his situation has taken a turn for the worse," he said at a news conference in Atlanta Sunday afternoon.
Officials here continued to scramble to contain the spread of the disease, monitor those Duncan came into contact with and decontaminate the Dallas apartment where he had been staying with his girlfriend and three of her relatives.
On Sunday, city and county officials said they had found a homeless man who was among those being monitored. The man rode in the ambulance that took Duncan to the hospital, before the vehicle was taken out of service and cleaned. Officials said the man, whom they identified as Michael Lively, had been monitored Saturday, was asymptomatic, and apparently went into hiding on Sunday before he was found.
Prosecutors here are considering whether to bring charges against Duncan following reports that he had contact with a woman who ended up dying of Ebola in Liberia and later lied about that contact before boarding a plane to the United States.
"We are actively having discussions as to whether or not we need to look into this as it relates to a criminal matter," Dallas County's district attorney, Craig Watkins, said on "Lone Star Politics" on NBC 5 on Sunday. "We're working with all the different agencies to get to the bottom of it." His spokeswoman said prosecutors had previously filed aggravated assault charges against people who were HIV positive and knowingly had unprotected sex with others; and it was possible the same charge may apply in Duncan's case.
At the apartment where Duncan and the others had been staying, about 20 containers were filled with linens and other items. The containers were being stored "in an extremely safe and secure location, and guarded by Dallas County Sheriff's deputies," said Sana Syed, a city spokeswoman.
The four others who had been living in the apartment - his girlfriend, one of her children and two young men - were moved to a temporary home Friday and remain under orders not to leave the premises. None of the four have reported any symptoms of Ebola, officials said.
Last week, Liberian officials said that Duncan lied about his history of contact with Ebola on an airport questionnaire meant to screen out passengers who might be carrying the virus and is subject to prosecution when he returns to the country.
The chairman of the Liberia Airport Authority said that when Duncan flew out of Roberts International Airport in Monrovia, the Liberian capital, on Sept. 19, he answered "no" to a question about whether he had contact with any person infected with Ebola in the last 21 days, the maximum period of incubation for Ebola. In addition, Texas Health Presbyterian said Duncan was asked by nurses if he had been around anyone who had been ill when he first went to the emergency room there on Sept. 25, and Duncan told them he had not.
Both of those answers appeared to be contradicted by Duncan's activities in the days before he left Liberia for the United States. In Monrovia, neighbors and the parents of Marthalene Williams, 19, a woman who died of Ebola, said Duncan had helped the family take her to and from a hospital on Sept. 15 shortly before she died. Some of the men and women who had direct contact with Williams, and who were also in contact with Duncan, have died in recent days, including Williams' brother, Sonny Boy Williams, 21.
Duncan landed in Dallas on Sept. 20, and went to the emergency room feeling ill on Sept. 25. He returned to the hospital three days later on Sept. 28 after his condition worsened.
It was unclear how the threat of charges being filed against Duncan will be viewed by African immigrants in the Dallas area. Liberians have already been on edge about coming into contact with anyone who may have come into contact with Duncan. Stanley Gaye, president of the Liberian Community Association of Dallas-Fort Worth, said some Liberian immigrants had told him they were concerned about being tested for Ebola because they feared being placed in isolation and having to skip work for the three-week incubation period.
"They're afraid to lose their jobs," he said. "People have to put food on the table."
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