Fifty Dallas-area people now require close monitoring for possible contraction of the Ebola virus, state officials said Friday afternoon — up from the initial number of 18 that they had given Wednesday. 

"There's now approximately 50 individuals that we need to follow on a daily basis," Dr. David Lakey, a commissioner at the Department of State Health Services, told reporters Friday.

He added that most of those people are at "low risk," but "about 10" are at "higher risk." Public health officials are paying twice-daily visits to each of those 50 individuals to check their temperature and inquire about possible symptoms for the virus, which include fever, diarrhea and abdominal pain.

The shifting numbers have drawn criticism that the response to the first case of Ebola in the United States has been uneven since Thomas Duncan was diagnosed at Texas Health Presbyterian Hospital in Dallas on Tuesday. Duncan had gone to the hospital with symptoms days earlier after arriving in Dallas from Liberia to visit family, but was at first sent home with antibiotics. He later returned and was diagnosed with Ebola. The hospital said his travel history had not been initially communicated to the appropriate medical staff. 

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But Lakey, Centers for Disease Control official Dr. Beth Bell, and Dallas County Judge Clay Jenkins told reporters Friday that the situation is under control. None of the individuals being monitored have displayed symptoms of Ebola, they said. 

"We have a very low bar for deciding to follow patients," Bell said. She added, “This does not imply that we have a high level of concern about most of these people." 

Still, she said, “there certainly is a possibility that some of the people who have already been in very close contact with this patient might develop Ebola.” She said a possible Ebola case at a Washington, D.C., hospital has not been confirmed. 

Those at "higher risk" in Dallas include the individuals that Duncan was staying with in an East Dallas apartment. They remain quarantined with a law enforcement officer stationed outside their door. 

Speaking with reporters, Jenkins expressed regret that they had been ordered to stay in the apartment and that Duncan's soiled clothing and bedding — likely contaminated with the bodily fluids that could cause others to become sick if they come in contact with it — were not removed until Friday. Jenkins has said it was difficult to find a cleaning service that would agree to remove the materials, and that there were further delays in getting needed permits dealing with hazardous waste. 

"Even as we speak now, we don't have the permits in place to dispose of the soiled items," Jenkins said. But since the county does not need a permit to transport them within its borders, Jenkins said that for now, it will be stored in a sealed container and guarded by law enforcement "in a site that is away from the urban population."

Jenkins said he visited the East Dallas apartment along with two epidemiologists from the Centers for Disease Control to apologize for the delays. "I want to see [the apartment's residents] treated as I would want my own family treated, and we are making efforts to make sure that their accommodations and their comfort improves," he said.