Edinburgh Legionnaires' disease cases rise further
Health officials have said the number of confirmed and suspected cases of Legionnaires' disease in Edinburgh has risen to 40.
Of these, one person has died, 12 remain in intensive care and two others have been discharged from hospital.
NHS Lothian has said it could take until the weekend before the extent of the outbreak is known.
Health Secretary Nicola Sturgeon said the suspected source was environmental contamination.
She said early indications suggested the outbreak was the result of a contaminated cloud being emitted from a cooling tower in the south west of the city.
Officials are now liaising with the Met Office to analyse the impact of temperature and wind speed on plumes from the towers.
So far in the outbreak there have been a total of 21 confirmed and 19 suspected cases.
Dr Duncan McCormick, chair of NHS Lothian's incident management team, said the majority of those affected were men aged between their mid-30s and late-80s.
He said two patients that had been "seriously unwell" had now been discharged, which was "really encouraging" and that the "treatment was working very well".
Although the number of suspected cases has risen, he said the numbers in intensive care had decreased.
Ms Sturgeon described the outbreak as a "significant event" for NHS Lothian and said the government had activated their emergency plan.
She said they expected to see a decline in the number of cases in the next five to six days as sixteen cooling towers in the city had been treated with chemicals to kill the bacteria.
However, Dr McCormick said, although they were "confident" they had identified the source, because of its incubation period, more cases of Legionnaires' disease were expected.
The Scottish government said they would be issuing information leaflets in the affected area of Edinburgh.
The BBC understands that tests have been carried out at four sites.
They include the cooling towers at;
- North British Distillery, Wheatfield Road, Gorgie
- McFarlan Smith (pharmaceuticals), Wheatfield Road, Gorgie
- Aegon (insurance), where towers are used to cool servers, in Lochside Crescent, South Gyle
- and Burtons Foods, Bankhead Place, Sighthill
A meeting of its resilience committee took place on Wednesday to co-ordinate the official response to the outbreak.
Dr McCormick told BBC Scotland he expected instances of the disease to peak in the coming days.
He said: "The incubation period of Legionnaires' disease is between two and 14 days but the average is five or six days, so we're expecting to have more cases over the next few days.
"But if our evidence and reaction have been correct, we hope to have removed the source through our shock treatment of these cooling towers.
"We'd hope that by the weekend - five or six days after the treatment, we'll start to see a decline in cases."
The 16 towers were identified as a potential source of the outbreak following the first reported case on Thursday last week.
They were chemically treated on Sunday night and Monday morning.
Dr McCormick said that people living in the Gorgie, Dalry and Saughton areas were generally at low risk.
He added: "I want to give that reassuring message.
"However, people who fall into certain risk groups, these are males who are adults, who have an alcohol, drinking habit and have an underlying illness such as diabetes, or heart disease or lung disease - these people are at greater risk.
"These people should be very much aware that if they start feeling symptoms of flu-like illness, together with diarrhoea, cough and confusion, they should be consulting their GP or NHS 24 as soon as possible."
Dr McCormick said there was no threat to the city's public water supply.
He added: "The public water supply in Edinburgh is extremely closely monitored and in addition it's not possible to contract Legionnaires' Disease through drinking water.
"It's contracted through the inhalation of water vapour in the form of an aerosol and that doesn't happen through drinking water supplies."
Martin Donaghy, the medical director of Health Protection Scotland, said the information so far suggested the outbreak contained the most common strain of the disease.
He added: "The secret with Legionnaires disease is to get treated with the right antibiotic as soon as possible."