Dallas Ebola patient in dire shape

Thomas Eric Duncan, the Ebola patient in a Dallas hospital is in dire shape. Health officials are keeping track of anyone he made contact with in order to prevent the virus from spreading further.

Meanwhile, the fifth American, Ashoka Mukpo, infected in West Africa arrived in Nebraska for treatment on Monday. He acquired the disease while working as a news cameraman in Liberia, reports CBS News correspondent Manuel Bojorquez.

Hazmat crews, covered from head to toe, completed another sweep of Duncan's apartment Sunday, where he stayed before being taken to the hospital.

Doctors so far have not used experimental treatments, like Zmapp, on Duncan.

"The medication... can be quite difficult for patients to take and can transiently worsen their conditions," CDC Director Tom Frieden said.

In the meantime efforts to isolate potential new cases continue.

"What we have seen is the efforts of the Dallas and the Texas state and CDC to track the contacts have been very well done," Frieden said on "CBS This Morning." "Every contact was identified and measured for temperature yesterday."

None of them have symptoms or fever so far.

"We're confident if there are any secondary cases there, we can stop the chain of transmission," Frieden said.

Health workers are checking on nearly 50 people who may have had contact with Duncan.

Authorities put out an alert yesterday when they couldn't locate Michael Lively, a homeless man considered a low-risk contact.

He was a patient in this ambulance immediately after Duncan. They found him within hours.

It was yet another challenge for officials trying to prove their efforts are working.

"I'm absolutely confident that we will stop Ebola from spreading here," Dallas Judge Clay Jenkins said.

As the county's top administrative official, he has emerged as the face of the response. He's visited quarantined family members without protective gear, and has even driven them to a new location: an isolated home in an undisclosed gated community, to calm public fears.

"There's zero chance you'll get Ebola from an asymptomatic person," Jenkins insisted.

He acknowledged there have been missteps, including the hospital's initial release of Duncan, when he first showed up with symptoms.

"Mistakes were made," Jenkins said. "The hospital has been very forthright that they made mistakes."

Although he said the county did not follow the designated protocol, Frieden reassured every person leaving the infected West African countries is subject to pre-flight health screenings.

"In fact we know that the patient in Dallas's temperature was 97.3 when he left Monrovia," he said. "In fact about 40,000 people have come in from those countries since the outbreak started and none of them had fever from Ebola when they came in."

And there is one other encouraging fact to note.

"We've seen no more cases in Nigeria, it looks like they've stopped it," Frieden said. "We've now trained 4,000 people across Africa, across these three countries, to fight Ebola, and we're seeing the first training in the U.S."

Sixty people are participating in CDC training for deployment in Africa to join hundreds around the world who are responding to the outbreak.