New York City Mayor Bill de Blasio speaks during a...

New York City Mayor Bill de Blasio speaks during a news conference at Bellevue Hospital on Thursday, Oct. 23, 2014. Credit: AP / John Minchillo

New York and New Jersey will automatically quarantine travelers who have treated or worked with Ebola patients in stricken West Africa, the states' governors announced Friday.

The stricter screening protocols at Kennedy and Newark Liberty airports came one day after Dr. Craig Spencer, who recently worked in Guinea for Doctors Without Borders, became the first person in New York and the fourth in the nation to contract the deadly virus.

Spencer, 33, of West Harlem, is in a special isolation ward at Bellevue Hospital Center in stable condition, health officials said.

For the second-straight day, New York City Mayor Bill de Blasio urged the public to remain calm and said the risk of contracting Ebola is extremely small.

Gov. Andrew M. Cuomo and New Jersey Gov. Chris Christie said at a news conference in lower Manhattan that current federal screening procedures at the airports weren't tough enough. The U.S. Centers for Disease Control and Prevention recommends monitoring of exposed people but doesn't require quarantine.

A 21-day quarantine -- the incubation period for the virus -- is now mandatory for all travelers deemed at risk.

"A voluntary Ebola quarantine is not enough. This is too serious a public health situation," Cuomo said.

Under the new protocols, even those with no direct contact with an infected person who have traveled to the three countries at the heart of the Ebola epidemic -- Liberia, Sierra Leone and Guinea -- "will be actively monitored by public health officials and, if necessary, quarantined."

The CDC said it sets baseline recommended standards, "but state and local officials have the prerogative to tighten the regimen as they see fit."

In other developments Friday:

New York City public health detectives went from Williamsburg in Brooklyn to lower Manhattan and Harlem, retracing Spencer's steps before he became ill.

City health officials said Spencer's fiancee and two friends have been quarantined but show no symptoms. Spencer, an emergency doctor with NewYork-Presbyterian Hospital/Columbia University Medical Center, was able to communicate via cellphone with friends and family, officials said.

The Metropolitan Transportation Authority said there's no indication the doctor was contagious when he rode the subway Tuesday and Wednesday.

A diverse team of disease detectives from the CDC are at Bellevue, assisting doctors there. The squad of experts includes an epidemiologist who will collect statistical data.

"They will assist with waste management and decontamination," CDC director Dr. Thomas Frieden said.

City health officials released a timeline of Spencer's activities from the day the emergency doctor departed Guinea on Oct. 14 to 10:15 a.m. Thursday -- when he reported a fever of 100.3 degrees and was rushed to the Manhattan hospital. Officials previously misreported that his fever was 103 degrees.

De Blasio said city health department officials have been to the three places that Spencer visited before he became symptomatic, clearing all of possible contamination: The Gutter, a Williamsburg bowling alley; The Blue Bottle Coffee stand at 10th Avenue and W. 16th St. on the High Line; and The Meatball Shop at 64 Greenwich St. in Manhattan.

New York City Health Commissioner Dr. Mary Bassett said the three people who had the most contact with Spencer -- his fiancee, identified as Morgan Dixon, and two friends -- have been served with quarantine papers that require them to be in isolation for 21 days. She said health department staff are visiting them daily to take their temperatures.

"They are well at this time. None are sick," Bassett said.

Dixon is at Bellevue, officials said. The whereabouts of the other two weren't disclosed.

Spencer's diagnosis was confirmed Friday by the CDC, officials said.

As a crew from Ronkonkoma-based Bio Recovery Corp. began disinfecting Spencer's apartment on West 147th Street, public officials and agencies took pains to reassure New Yorkers.

"There is no indication the patient was contagious when he rode the subway," the MTA said, noting that subway ridership Friday appeared normal.

But based on advice from health experts, the agency said it has updated its protocols to ensure employees are issued nitrile gloves, use a 10 percent bleach solution for disinfection and double-bag any potentially infectious waste.

"The situation is being handled and handled well," said de Blasio, who rode the subway to allay fears. "Ebola is an extremely hard disease to contract. It requires direct contact of blood and bodily fluids."

Outside Bellevue Friday morning, patients and employees had mixed reactions to Spencer's presence on the seventh floor.

David Noferi, 66, of SoHo, said he was only nervous about his own appointment. "They caught it just in time for this gentleman," the retired doorman said of Spencer. "He's a doctor; he's helping people. Now we gotta help him."

But Georgiana Ochilly, a labor-and-delivery nurse from St. Albans, Queens, said she and other Bellevue nurses are concerned.

Although the hospital is offering training for nurses who volunteer to care for the doctor, Ochilly, 59, said she was unsure whether the preparations are adequate, citing two nurses in Dallas who were infected while caring for an Ebola patient.

"They did everything they had to do, and they still came down with the sickness," she said.

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Reexamining a cold case mystery ... Gillen heads to Washington ... Get the latest news and more great videos at NewsdayTV

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Reexamining a cold case mystery ... Gillen heads to Washington ... Get the latest news and more great videos at NewsdayTV

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