Updated

The father-in-law of the 31-year-old man under federal quarantine with a rare and dangerous form of tuberculosis is one of the leading TB researchers at the Centers for Disease Control and Prevention in Atlanta, FOX News has learned.

Dr. Robert Cooksey, who is a research microbiologist in the CDC's Division of Tuberculosis Elimination, confirmed to FOX News that he is the father-in-law of Andrew Speaker, a personal-injury lawyer who practices in his father's law firm in Atlanta.

Asked by FOX News whether it was possible that he had passed along the dangerous strain to his son-in-law, Cooksey said, "Absolutely not."

In a statement, Cooksey later said he is regularly tested for tuberculosis and has never had it.

"My son-in-law's TB did not originate from myself or the CDC's labs, which operate under the highest levels of biosecurity," he said.

Cooksey went on to say that he had nothing to do with his son-in-law's decisions to travel while infected.

"As a parent, frequent traveler, and biologist, I well appreciate the potential harm that can be caused by diseases like TB. I would never knowingly put my daughter, friends or anyone else at risk from such a disease," he said.

"I would ask the media to respect my privacy and that of my family, and I will be respectfully declining all media requests," Cooksey added. "My thoughts and focus over the next few months will be with my family, and we are hopeful that Andrew will have a fast and successful recovery."

Speaker, who earlier Thursday was transferred to Denver's National Jewish Medical and Research Center for treatment, touched off an international TB alert earlier this week when it was discovered that he had flown from Atlanta to Europe in mid-May for his wedding and honeymoon, all the while knowing that he had been diagnosed with the disease.

Speaker claims he did not find out until he was already in Europe that he was infected with an extensively drug-resistant strain of TB considered especially dangerous.

Despite warnings from federal health officials not to board another long flight, he flew home for treatment fearing he wouldn't survive if he didn't reach the U.S.

Health officials in North America and Europe are now trying to track down about 80 passengers who sat near him on the two trans-Atlantic flights, and they want passenger lists from four shorter flights he took while in Europe. Patients on the shorter flights are not expected to be as much at risk, health officials said.

Speaker, meanwhile, walked under his own power into National Jewish Medical and Research Center after flying from Atlanta with his wife and federal marshals, hospital spokesman William Allstetter said.

He looked healthy and tan, and "he said he still felt fine," Allstetter said.

Doctors plan to begin treating Speaker immediately with two antibiotics, one oral and one intravenous. He also will undergo a basic physical exam, a test to evaluate how infectious he is and a CT scan and lung X-ray, Allstetter said. Doctors hope to also determine where he contracted the disease.

He will be kept in a special unit with two rooms and a ventilation system, Allstetter said.

"He may not leave that room much for several weeks," Allstetter said.

According to a biography posted on a Web site connected with Speaker's law firm, he attended the U.S. Naval Academy, graduated from the University of Georgia with a degree in finance, then attended University of Georgia's law school.

His father, Ted Speaker, unsuccessfully ran for a Fulton County Superior Court judgeship in 2004, the same year his son was admitted into the Georgia Bar.

Andrew Speaker recently moved from an upscale condominium complex in anticipation of his wedding, former neighbors said. He also wrote in an application to become a board member of his condo association that he was going to Vietnam for five weeks as part of the Rotary club to act as an ambassador.

"He's a great guy. Gregarious," said Pam Hood, a former neighbor. "He's a wonderful guy. Just a very, very pleasant man."

Among those being tested for the strain are more than two dozen University of South Carolina Aiken students, school spokeswoman Jennifer Lake said Thursday. Two were apparently sitting near him, possibly in the same row, she said.

One of those students, Laney Wiggins, said she is awaiting her skin test results, expected Friday.

"I'm very nervous," Wiggins told The (Columbia) State newspaper. "It's kind of sad that this is overshadowing the wonderful time we had in Europe."

Speaker had flown to Paris on May 12 aboard Air France Flight 385, also listed as Delta Air Lines codeshare Flight 8517, according to the Centers for Disease Control and Prevention.

He and his bride also took four shorter flights while in Europe — Paris to Athens on May 14; Athens to Thira Island May 16; Mykonos Island to Athens May 21; and Athens to Rome May 21 — but CDC officials said there was less risk of infection during the shorter hops compared to the trans-Atlantic flights, which each lasted eight hours or more.

It was while they were in Rome that he learned further U.S. tests had determined his TB was the rare, extensively drug-resistant form, far more dangerous than he knew. Officials told him turn himself over to Italian health officials and not to fly on any commercial airlines.

Instead, on May 24, he flew from Rome to Prague on Czech Air Flight 0727, then flew to Montreal aboard Czech Air Flight 0104 and drove into the U.S., according to CDC officials.

Officials are trying to contact people who sat within five rows of him on the two longest flights for testing.

Other passengers are not considered at high risk of infection because tests indicated the amount of TB bacteria in the man was low, said Dr. Martin Cetron, director of the CDC's division of global migration and quarantine.

Speaker told The Atlanta Journal-Constitution that he wasn't coughing and that doctors initially did not order him not to fly and only suggested he put off his long-planned wedding. "We headed off to Greece thinking everything's fine," he told the newspaper.

Dr. Charles Daley, head of the infectious disease division at National Jewish Hospital, said the hospital has treated two other patients with what appears to be the same strain of tuberculosis since 2000, although that strain had not been identified and named at the time. He said the patients had improved enough to be released.

"With drug-resistant tuberculosis, it's quite a challenge to treat this," Daley said Thursday. "The cure rate that's been reported in other places is very low. It's about 30 percent for XDR-TB."

"This is a different patient, though. We're told that this is very early in the course, and most of the time when we get patients that it's very extensive and very far advanced. So I think we're more optimistic," he said. "We're aiming for cure. We know it's an uphill battle, but we hope to get there."

The Associated Press contributed to this report.