ATLANTA - Health officials in North America and Europe sought passenger lists Wednesday for two trans-Atlantic airline flights in their effort to find about 80 people who sat near a honeymooner infected with a dangerous drug-resistant form of tuberculosis.

Authorities also disclosed that the man was on several flights between various European locales over the course of two weeks earlier this month. Passengers lists for those flights were also being tracked down, they said.

"The investigation is just beginning. It's very challenging," said Dr. Martin Cetron, director of the Centers for Disease Control and Prevention's division of global migration and quarantine.

The man, who is under the first U.S. government-ordered quarantine since 1963, told a newspaper he flew from Atlanta to Greece for a wedding and then traveled to Italy for a honeymoon. Later he flew back to North America because he feared he might die without treatment in the United States.

CDC officials are concentrating on the trans-Atlantic flights, when the likelihood of spreading the disease was greatest because he was in a confined space with other people for hours. Officials were trying to contact 27 crew members and about 80 passengers who sat in the five rows surrounding the man for testing.

Other passengers on the flights are not considered at high risk of infection because tests indicated the amount of TB bacteria in the man was low, Cetron said.

"Our big concern is that no one has told us which row he might have sat on," passenger Shannon Boccard, whose 10-year-old son was on the same flight, told WSB-TV in Atlanta.

Health officials in France have asked Air France-KLM for passenger lists, and the Italian Health Ministry also is tracing the man's movements. A spokeswoman for Czech airline CSA said medical checks showed no infections among its crew members who flew with the man, but the airline was contacting passengers.

The man had a supply of masks to wear for the protection of other passengers, but it is not clear whether he donned them, Cetron said. The man continues to feel well and shows no symptoms, Cetron said.

The man told The Atlanta Journal-Constitution that doctors did not order him not to fly and only suggested he put off his long-planned wedding. He knew he had a form of tuberculosis and that it was resistant to commonly used drugs, but he did not realize until he was already in Europe that it could be so dangerous, he said. The man's wife has tested negative.

"We headed off to Greece thinking everything's fine," he told the newspaper. The newspaper did not identify him at his request, because of the stigma attached to his diagnosis.

He flew to Paris on May 12 aboard Air France Flight 385, also listed as Delta Air Lines codeshare Flight 8517.

He and his bride took then took four more flights within Europe, flying from Paris to Athens on May 14; from Athens to Thira Island on May 16; from Mykonos Island to Athens on May 21; and from Athens to Rome on May 21.

The passengers on the shorter European hops are not considered to be at the same level of risk for infection as the passengers on the trans-Atlantic flights, which each lasted eight hours or more, CDC officials said.

While he was in Rome, health authorities reached him with the news that further tests had revealed his TB was a rare, "extensively drug-resistant" form, far more dangerous than he knew. They told him to turn himself over to Italian health officials and not to fly on any commercial airlines.

Instead, on May 24, the man flew from Rome to Prague on Czech Air Flight 0727. From Prague, the couple left for Montreal the same day, aboard Czech Air Flight 0104, according to CDC officials.

The man then drove into the United States at Champlain, N.Y. He told the newspaper he was afraid that if he did not get back to the U.S., he wouldn't get the treatment he needed to survive.

The man is now at Atlanta's Grady Memorial Hospital under the first federal quarantine order since the government quarantined a patient with smallpox in 1963. A sheriff's deputy was assigned to guard him. He is not facing prosecution, health officials said.

A spokesman for Denver's National Jewish Hospital, which specializes in respiratory disorders, said Wednesday that the man would be treated there. It was not clear when he would arrive.