A US man put under quarantine after being found to have a rare strain of tuberculosis has been moved from Atlanta to a specialist Denver clinic.
The Denver clinic specialises in respiratory conditions
Andrew Speaker, a 31-year-old lawyer, could be treated for months, restricted to a room with special ventilation.
US authorities have launched a worldwide search for people who may have come into contact with him during two trans-Atlantic flights.
European officials are also trying to trace passengers who sat near him.
The European Centre for Disease Control (ECDC) considered the risk of contracting the drug-resistant disease to be low, a European Commission spokesman said.
Nevertheless it was recommending that people who sat in the same row or in the two rows in front of or behind him to be checked.
Mr Speaker travelled from Atlanta to Paris on 12 May on Air France flight 385. He returned to the North America on CSA flight 104 from Prague to Montreal on 24 May and continued his journey into the US by car.
He was honeymooning in Italy when he was told he had the rare form of TB - but still decided to return home.
His new father-in-law is a microbiologist who specialises in the same disease at the Centers for Disease Control and Prevention (CDC) in the United States.
Robert Cooksey says he was not involved in his son-in-law's decision to travel.
The personal injury lawyer was initially placed under federal quarantine at an Atlanta hospital, the first such order since 1963.
The CDC has identified the TB as "extensively drug-resistant".
Tuberculosis is a bacterial infection spread through the air
Mr Speaker told the Atlanta Journal-Constitution that he knew he had a form of tuberculosis but not that it was so serious. He told the paper doctors had not told him to avoid flying, the Associated Press said.
He has now been transferred to the National Jewish Medical and Research Center in Denver.
Treatment could take weeks or even months, spokesman William Allstetter told the Denver Post newspaper.
He will be restricted to a special "negative pressure" room that traps and cleanses air particles, and medical staff will wear masks when in contact with him.
Tuberculosis is a bacterial infection that usually attacks the lungs. It is spread through the air and can lead to symptoms such as chest pain and coughing up blood.
There were an estimated 1.6 million deaths from TB in 2005, according to the World Health Organization (WHO).
TB is rare in the US. Last year there were 13,767 recorded cases or 4.6 cases per 100,000 Americans.
About 1.2% of cases in the US are "multidrug-resistant", and can withstand antibiotics commonly used to treat the illness, according to CDC statistics.
The "extensively drug-resistant" TB is more dangerous. Medical treatment can cost $500,000 (£250,000) or more, CDC officials say.