DALLAS - The White House says that a ban on travel to Ebola-affected countries in West Africa would be counter productive. Homeland Security Advisor Lisa Monaco said that a travel ban would "actually impede the response" to Ebola cases in affected countries and that airport screening procedures are keeping ill people off planes.

Speaking at a Friday press briefing, Monaco said that airport screening, which has been in effect since the summer, has been "effective" preventing "dozens and dozens of people" from getting on planes. The procedures check for temperature and other symptoms of illness.  

Also during that time, Monaco said, "tens of thousands of individuals have come to the United States from this region [West Africa]. We now have this isolated case in Texas."

Watch related video report by VOA's Aru Pande from the White House:

Liberian national in Dallas

The first person to be diagnosed with Ebola in the United States was in serious, but stable condition, at a Dallas hospital as health workers monitored four family members and others who had contact with Liberian national Thomas Duncan after he arrived from Liberia, officials said.

Health officials with the U.S. Centers for Disease Control and Prevention in Atlanta, Georgia, say they now are monitoring about 50 people who had direct or indirect contact with Duncan.

Dr. Beth Bell of the CDC told reporters Friday that officials are being "extremely cautious" with those contacts, but added that such caution does not imply "a high level of concern."

Of the people being monitored, about 10 are considered at high risk, while the rest are considered at low risk, according to Dr. David Lakey, commissioner of the Texas Department of State Health Services.

A cleanup crew worked throughout the day to decontaminate Duncan's Dallas apartment Friday. Four family members who had been quarantined there have been relocated to an undisclosed location.

An infected U.S. cameraman working for NBC News in Liberia will arrive Monday in the U.S. Ashoka Mukpo's father said his son will be treated at a facility in Omaha, Nebraska. The father said Mukpo "is weak. He has some fever and he's got some muscle aches, but he's in the early phases, so basically he doesn't feel too badly."

Possible case in Washington

Meanwhile, a patient in a Washington, D.C., hospital is being monitored for possible Ebola. At the Friday news briefing, Secretary of Health and Human Resources Sylvia Burwell said the patient's symptoms were "malarial" but could be Ebola.

Kerry-Ann Hamilton, a spokeswoman for Howard University Hospital, said the patient who recently traveled to Nigeria was in stable condition.

Hamilton said medical authorities have isolated the patient and "activated the appropriate infection control protocols."

Controversy swirls

Controversy continued over the Dallas hospital’s failure to immediately isolate Duncan.

Dr. Tom Kenyon, director of global health at the U.S. Centers for Disease Control and Prevention, said such mistakes come with the appearance of an epidemic.

“It is inevitable that the longer this epidemic exists, the bigger it gets, the greater the risk of importation events like we have just seen,” Kenyon told reporters Thursday. “So, while we regret that this [Texas case of Ebola] has occurred, we hope the best for the gentleman's health.

“We do want to point out that this is not a failure of the screening system. It is a reality of the epidemic that we find ourselves in," he said.

Children being monitored

Officials have said some school-age children are among those being monitored for having contact with Duncan. He has been isolated in a special ward, under treatment for his symptoms.

There is no proven cure for Ebola, though a drug manufactured by a U.S. company has shown promise.

Some Dallas residents have said openly they fear what would happen if others end up being infected.

Local media reports have said parents of some children who attended the same school as the children now quarantined have been keeping their own children away.

“At first it was just over in Africa, but now it is here, so it is something local. It is not widespread, but it’s still here,” said one man, who declined to give his name.

Others, however, have expressed little worry.

“I am not really concerned. It is at the hospital and I am not in contact with anyone who is affiliated with it,” one woman told VOA.

“It is so far beyond my capability to do anything about it that I am just going to trust," another man said.

Confidence in medical system

Gabriel Ogueri, who immigrated to the United States from Nigeria, said he was confident the U.S. medical system would prevent the spread of the virus.

“We have what it takes to eradicate it. I am not scared at all,” Ogueri said.

Ebola experts have said the best way to prevent further infections in the United States or elsewhere is to defeat the disease in West Africa, where health infrastructure and medical care remain inadequate.

More than 3,000 people have died of Ebola this year in the worst outbreak ever, according to the World Health Organization. Liberia, Sierra Leone and Guinea have been the worst affected.

Some material for this report came from AP and Reuters.