New York and New Jersey Tighten Ebola Screenings at Airports

As disease investigators sought to ensure on Friday that they had found and isolated everyone who came into contact with New York City's first Ebola patient when he was sick and infectious, doctors treating the man were discussing using experimental treatments to help him battle the virus.

Health officials said that the initial reports were incorrect when they indicated that Dr. Craig Spencer, 33, had a 103-degree fever when he notified authorities of his illness on Thursday. He actually only had a 100.3 fever. Officials attributed the mistake to a transcription error.

Dr. Spencer had been working with Doctors Without Borders in Guinea, treating Ebola patients, before returning to New York City on Oct. 14, according to a city official.

Health officials said that Dr. Spencer reported his symptoms to authorities at around 11 a.m. on Thursday and was quickly rushed to Bellevue Hospital Center and put into isolation.

He still had only a low grade fever.

A hazardous material team was dispatched to the man's apartment in Harlem, where they were going to sanitize the residence, even as public officials took to the airwaves seeking to reassure wary residents that the risk to the general public was exceedingly small.

'Being New Yorkers, a little anxiety can keep you safe,' Gov. Andrew M. Cuomo said. 'It's not a bad thing. But undue anxiety is unproductive.'

Much of the public's concern focused on the movements of the patient the night before he reported feeling ill on Thursday morning.

He traveled on several subway lines, went bowling in Brooklyn and took a taxi back to Manhattan on Wednesday. He assured officials that he was not symptomatic at the time.

As the disease continues to spread, killing thousands in West Africa and popping up in a growing number of cities around the world, federal health officials on Friday said they were considering stepping up precautions to guard against new cases in this country even more.

'There are lots of options on the table,' said a federal official. 'There are far-reaching implications for all of them. So we need to look carefully at the issue and that is what we are doing.'

The Ebola virus can only be transmitted to other people through bodily fluids when an infected individual begins to show symptoms. At the onset of illness, the amount of virus in the body is generally low, so the risk of infection is also considered small.

As the disease progresses, the amount of virus in the body multiplies and so does the risk of contagion.

The question of exactly when Dr. Spencer started developing symptoms is critical because the authorities want to find anyone he came into physical contact with during this period, no matter how small the risk of contagion.

Dr. Spencer's fiancée, Morgan Dixon, who lived with him, has been quarantined at Bellevue Hospital. Two other friends whom he had contact with have also been quarantined.

None of them have shown any symptoms of illness.

Health workers were scheduled to visit the bowling alley in Williamsburg, Brooklyn, where Dr. Spencer bowled when it opens at 2 p.m. on Friday. They are not planning on cleaning the facility, but rather, interviewing people there to be sure that he did not have any unknown contacts.

'There is the pure science in terms of what we know and what can come from that,' said Dr. Irwin Redlener, the director of the National Center for Disaster Preparedness at Columbia University and a special adviser to Mayor Bill de Blasio. 'On the other end of the spectrum, there is the world of abundance of caution. Public officials are constantly trying to find the right balance.'

Soon after Dr. Spencer was diagnosed with Ebola on Thursday, Governor Cuomo and Mayor Blasio participated in a conference call with federal, state and local health officials to determine if they needed to take any action regarding the subway cars on which Dr. Spencer rode on Wednesday.

Although he was not believed to be symptomatic at the time, they wanted to know what the likelihood of spreading the disease would have been if that assumption was mistaken, according to someone who heard the discussion.

They were told that the virus is not expected to live more than two to four hours on a surface and there was only the remotest of possibilities that a rider could be infected.

'This is so close to zero risk,' one expert said in the call. And at this point, even if there was some virus that managed to have found its way onto a surface, it would be dead.

The decision was made to keep the trains in service, since to do anything else might cause undue panic and do more harm than good.

Dr. Spencer told the authorities that he did not believe the protective gear he wore in Guinea while working with Ebola patients had been breached, but had been monitoring his own health.

Dr. Kalissa N'fansoumane, head of the health district in Gueckedou, Guinea, confirmed by phone that Dr. Spencer worked for the group in his district.

Dr. N'fansoumane said the charity would not provide him with additional details.

'They're always hiding information,' he said. A former worker with the charity, who asked not to be identified because of the sensitivity of the situation, said that staff had received an email on Thursday evening asking them not to speak with the media about Dr. Spencer's case.

Doctors Without Borders, in a statement, said it provided guidelines for its staff members on their return from Ebola assignments.

'The individual engaged in regular health monitoring and reported this development immediately,' the group said in a statement.

New York officials said Dr. Spencer was taking his temperature twice daily since his return.

Still, officials cautioned that the investigation might find more people who are at risk.

'It is very possible that we'll see the need for tracking additional individual,' according to a health official involved in the response. 'This is a dynamic process.'