'Tuberculosis is rare but it has not gone away', the region's top TB specialist warned yesterday, after a single strain of the disease in Birmingham spread through a group of clubbers, killing one.
The six victims, aged between 20 and 40, are believed to have become infected via a network of social contacts and nightclub venues they visited.
The source of their disease - the rare bovine form of tuberculosis - is thought to be the unpasteurised milk which one of them drank many years ago.
The outbreak came to light after sophisticated testing revealed all six had contracted a virtually identical strain of the disease within an 18-month period from late 2004.
Earlier this year Peter Hawkey, Professor of Public Health Bacteriology for the Midlands, was creating a database of the DNA 'fingerprints' of each strain of bovine TB diagnosed over the last three years.
He noticed that six of them were almost exactly the same, and his finding sparked a Sherlock Holmes-style investigation into how the patients were connected and what the source might be.
"Two were connected because they were partners, a man and a woman, but we asked 'how did the other four fit in round this couple?'," said Prof Hawkey.
"One of them had his case diagnosed in 2004, and years ago he had consumed unpasteurised milk, and had temporarily worked on a farm as well."
Bovine TB is a disease which can affect the bowel and lies dormant for many years, he said. But it can flare up and cause a lung infection.
He said it was not known for certain that this was what had happened but it seemed likely. Close questioning revealed he was a friend of this couple and frequented the same pub as them. Prof Hawkey said: "The mystery was then, how did the other three fit in? We found that one worked in a club in Birmingham city centre and another was a doorman there.
"A third occasionally visited it, and then it turned out that the couple also visited the club. All five were part of a clubbing scene."
The disease, he said, had been passed on via respiratory routes.
He said in the last century innkeepers and those who frequented inns were most prone to catching TB. Modern nightclubs created similar conditions, with people crowded together in smoky places with poor ventilation, and coughing.
On average just three people in the Midlands contract bovine TB, or mycobacterium bovine, each year.
The human form of the disease - mycobacterium TB - is much more common than the bovine form, with around 1,000 cases diagnosed in the Midlands every year.
It is most prevalent among people aged 60 plus - whose immune system may be compromised or who may have drunk unpasteurised milk - and those who have visited the Indian or African sub-continent.
"The message is that TB has not gone away," said Prof Hawkey. Symptoms included persistent weight loss, night sweats, tiredness and a cough.
"If you get these it is important to get them checked."