Doctors in Glasgow are treating Scotland's first diagnosed case of the drug-resistant XDR tuberculosis strain.
One and a half million people die from TB every year
The man who has the XDR-TB strain is reported to have come to the UK from Somalia. He is now in isolation at the Gartnavel General Hospital.
The "super strength" strain of the disease is extremely resistant to traditional antibiotics and has to be treated with a cocktail of drugs.
Doctors have said there is no risk to the general public.
This is the first case of its kind reported in the UK since the revised definition of XDR-TB was published by the World Health Organization in 2006.
However, an earlier case in 2003 was retrospectively identified as XDR-TB.
The disease is prevalent in many other countries.
About half of XDR-TB cases are fatal. It can take up to 18 months for an infected patient to recover.
XDR-TB needs to be treated with a combination of antibiotics to ensure that the treatment is successful in curing the patient and preventing transmission to others.
Tuberculosis spreads through close and prolonged contact with the infected person.
TB is a disease which usually attacks the lungs, but it can affect almost any part of the body.
A person with TB does not necessarily feel ill but the symptoms can include a cough that will not go away, feeling tired, weight loss, loss of appetite, fever, night sweats and coughing up blood.
Dr Oliver Blatchford, a public health consultant at NHS Greater Glasgow and Clyde, said XDR-TB is no more infectious that ordinary TB but does require different treatment.
Dr Blatchford added: "The contacts of this case are being screened in the same way as ordinary TB contacts and will be monitored closely to ensure that any further cases are identified early and treated quickly."
Dr Jim McMenamen, a consultant epidemiologist at Health Protection Scotland, added: "I don't think that there's any risk to the general population because we have taken very prompt measures to try and manage the chance of this person spreading the infection to others."
Nearly nine million people a year fall ill from TB and more than one and a half million die from it.
The World Health Organization estimates that nearly 500,000 people a year become infected with drug-resistant TB.