John Bacon

USA TODAY

The first nurse to test positive for the Ebola virus arrived in Maryland Thursday evening on a chartered flight from Dallas, bound for treatment at a federal hospital outside Washington, D.C.,

Nina Pham, saying "I'm doing really well,'' left Texas Health Presbyterian Hospital in an ambulance for a chartered small jet waiting at the city's Love Field. The plane departed at 7:09 p.m. CT and arrived at an airport at Frederick, Md., less than three hours later.

Pham walked off the plane with assistance while wearing a protective suit. She climbed into an ambulance for transport to the National Institutes of Health's state-of-the-art facility in Bethesda, Md.

Fellow health-care workers lined her path out of the Dallas hospital, cheering and waving signs expressing love and support for their colleague.

Pham contracted the virus while treating Thomas Eric Duncan, who died Oct. 8, at the Dallas hospital. A second nurse who caught the virus was transferred a day earlier to a hospital in Atlanta.

Officials at the Dallas hospital said Pham was being transferred out of concern the Ebola crisis had left it overwhelmed and short of critical staff.

"With so many of the medical professionals who normally staff our intensive care unit sidelined for the continuous monitoring, we felt it was in the best interest of the hospital's employees, the nurses, the physicians, the community, to give the hospital an opportunity to prepare for ... for whatever comes next," hospital spokesman Wendell Watson said.

The hospital released a statement from Pham thanking the hospital and others.

"I'm so thankful for the outpouring of love and support from friends and family, my coworkers and complete strangers. I feel very blessed and have gained strength from their support,'' she said. "I'm doing really well thanks to this team, which is the best in the world. I believe in my talented coworkers.''

Pham's condition "is stable and she seems to be doing reasonably well," Fauci told a U.S. House panel holding a hearing on the Ebola response. But he added that the NIH only has room for two Ebola patients.

The NIH said Pham will be treated in the Special Clinical Studies Unit "specifically designed to provide high-level isolation capabilities and is staffed by infectious diseases and critical care specialists."

Also Thursday, Ebola screening at four major U.S. airports was stepped up and some schools in Ohio and Texas closed as controversy intensified over efforts by federal health officials and Texas Health Presbyterian to protect Americans from the deadly virus.

The screenings began at Washington Dulles International, Newark Liberty International, Hartsfield-Jackson Atlanta International and Chicago O'Hare International airports. Screening of passengers arriving from West Africa began Saturday at Kennedy International Airport in New York.

Agents with the Department of Homeland Security's Customs and Border Protection are intercepting travelers from Guinea, Liberia and Sierra Leone, taking their temperature and observing them for other Ebola symptoms. A passenger with symptoms will be isolated while personnel with the Centers for Disease Control and Prevention determine whether the traveler can continue the trip or requires hospitalization.

But it's not just airline travel from West Africa that is causing concern.

In Ohio, two schools were closed Thursday and a third was disinfected overnight, citing the slim possibility that staff members may have been exposed to Ebola on a domestic Frontier Airlines flight. An e-mail sent to parents by the Solon City School District said the schools were closed after district officials learned a middle school staff member may have traveled aboard the same airplane, though not the same flight, as Dallas nurse Amber Joy Vinson.

Vinson, 29, is one of two nurses who contracted Ebola after caring for Duncan, who died Oct. 8 at Texas Health Presbyterian Hospital in Dallas. Vinson had a slight fever when she took the flight from Cleveland to Dallas on Monday; CDC officials had approved Vinson for the flight because her temperature was below the threshold in CDC protocols.

Three Central Texas schools were closed after two students traveled on Vinson's flight.

The Frontier Airlines plane that carried Vinson was flown to Denver International Airport late Wednesday and cleaned three times, the airline said. Frontier also said it was grounding six members of the flight's crew as a precaution.

Also Thursday, Texas Health Presbyterian defended its Ebola procedures, saying it followed CDC protocols. At a news conference Wednesday, leaders of National Nurses United had accused the hospital of mishandling care of Duncan, the first person diagnosed with Ebola in the United States.

Deborah Burger, co-president of the nursing group, said nurses assigned to care for Duncan weren't given proper training or proper personal protective equipment and were assigned to care for other patients, potentially exposing them to Ebola. Duncan was left in an area with other patients for hours after he was diagnosed rather than immediately isolated, she said.

Burger also said blood samples taken from Duncan were sent through the hospital's general tube delivery system, rather than hand-delivered to a lab. She said that could potentially contaminate the entire tube system.

The hospital also failed to promptly remove waste contaminated with Ebola, which was stacked "to the ceilings," Burger said.

The hospital responded Thursday, saying in a news release that Duncan was quickly placed in isolation when he returned to the hospital and was suspected of being infected, that staff wore appropriate protective equipment and that none of Duncan's fluids ever leaked into the tube system.

Regarding hazardous waste, the hospital said it "went above and beyond the CDC recommendations. Waste was well-contained in accordance with standards, and it was located in safe and containable locations."

CDC protocols are just one of the Ebola issues to be raised at the House hearing.

"Just a few weeks ago, there was an urgent need to quickly stop the spread of Ebola in Africa, but now we also need to assure Americans that we are able to stop the spread here at home," said Rep. Tim Murphy, R-Pa., chairman of the Oversight and Investigations Subcommittee of the Energy and Commerce Committee. "There is no room for error when it comes to Ebola."

Contributing: Erin Kelly in Washington, William M. Welch in Los Angeles; WKYC-TV, Cleveland