OMAHA, Neb. (AP) — An American video journalist who contracted Ebola while working in Liberia stepped off a jet Monday under his own power on his way to a Nebraska hospital where he will be treated for the disease in a specialized containment unit.

Ashoka Mukpo, 33, was then loaded onto a stretcher for the ambulance ride to the Nebraska Medical Center.

Mukpo was working as a freelance cameraman for NBC News when he became ill last week. He is the fifth American with Ebola to return to the U.S. for treatment during the latest outbreak, which the World Health Organization estimates has killed more than 3,400 people.

Mukpo’s parents said they tried to talk him out of going to Liberia last month, but he told them he wanted to help show the severity of the epidemic.

“I told him I thought he was crazy,” said his father, Dr. Mitchell Levy.

“And I begged him from a mother’s perspective, I said please don’t go,” Diana Mukpo said. “But there was nothing to do. He was determined.”

Before returning to Liberia last month, Mukpo had lived there for two years while working as a researcher for the Sustainable Development Institute, a nonprofit focused on the concerns of workers in mining camps outside Monrovia. He only returned home to Providence, Rhode Island, in May.

His symptoms of fever and nausea still appeared mild, Levy said.

It’s not clear how Mukpo was infected, but Levy said it may have happened when he helped clean a vehicle someone died in.

During his treatment, his parents will have to rely on a video chat system in his hospital room to communicate with him.

Meanwhile in Texas, a Liberian man with Ebola who started showing symptoms while visiting the U.S. remained in critical condition at a Dallas hospital.

Texas Gov. Rick Perry said he would create a state task force to ensure Texas develops a rapid-response plan if an outbreak develops in the state.

Perry also called on federal officials to implement screening procedures at all U.S. points of entry. He said screeners should take travelers’ temperature and conduct other assessments to determine their overall health.

Doctors at the Nebraska isolation unit — the largest of four in the U.S. — will evaluate Mukpo before determining how to treat him. They said they will apply the lessons learned while treating American aid worker Rick Sacra, who was allowed to return home to Massachusetts after three weeks, on Sept. 25.

Sacra received an experimental drug called TKM-Ebola, as well as two blood transfusions from another American aid worker who recovered from Ebola at an Atlanta hospital. The transfusions are believed to help a patient fight off the virus because the survivor’s blood carries antibodies for the disease.

In Dallas, another man who recently traveled to the U.S. from Liberia was listed in critical condition. Thomas Eric Duncan has been hospitalized at Texas Health Presbyterian Hospital since Sept. 28.

Dr. Tom Frieden, the CDC’s director, said he was aware that Duncan’s health had “taken a turn for the worse,” but he declined to elaborate.

Officials are monitoring the health of nearly 50 people who had varying degrees of contact with Duncan.

Dallas City Council member Jennifer Staubach Gates, who represents the neighborhood where Duncan fell ill, said some fearful volunteers are refusing to enter the area, which is forcing nonprofit organizations to recruit additional volunteers.

She told reporters Monday that residents of the neighborhood have been turned away from their workplaces and retailers. She said they are being directed to legal-aid representatives for assistance.

The virus that causes Ebola is not airborne and can only be spread through direct contact with the bodily fluids — blood, sweat, vomit, feces, urine, saliva or semen — of an infected person who is showing symptoms.