Edinburgh Legionnaires' outbreak: Expert says four cases sparked response
The public health consultant who led the response to Edinburgh's deadly Legionnaires' Disease outbreak has outlined his actions to MSPs.
Dr Duncan McCormick, of NHS Lothian, said the outbreak, which killed two and hospitalised dozens, was declared after confirmation of three or four cases.
The appearance before Holyrood's committee came in light of case numbers rising to 95.
There are now 48 confirmed and 47 suspected cases.
It is believed the source of the outbreak, which began at the end of May, was a cooling tower in the south of the capital.
The Health and Safety Executive and Edinburgh City Council are continuing their investigations into the possible source of the outbreak and an interim report on the outbreak is being considered on Wednesday.
Dr McCormick, who chaired the incident management team linked to the outbreak, told MSPs the first case of Legionnaires' Disease emerged on Thursday 31 May, after the individual was admitted to hospital the day before.
A second case emerged on the Saturday, with an assessment throwing up a close geographical link between the cases.
After a third case emerged on Sunday lunchtime, with another an hour later, Dr McCormick said: "It was clear we did have an outbreak".
He said an incident team had swung into action by about 16:00, and after working out the cases appeared in a cluster, said: "The hypothesis we made was that it was an outdoor, external source which was somehow infecting people who had no other links, other than the fact that they lived in that area."
Dr McCormick said registered cooling towers in the area were identified and action started being taken on Sunday evening under a plan which also saw the public informed.
He explained: "When you have a single case, we're always vigilant for any other cases.
"When you have two, you become more vigilant and you make sure the clinical partners are informed so they can identify new cases coming up.
"When you have three, then this is an outbreak and then you take action."
Pam Waldron, health and safety executive director for Scotland, told the committee that three improvement notices were served on companies in Edinburgh in relation to the incident, two on pharmaceutical company Macfarlan Smith and one on the North British Distillery.
She said the last inspection of the Macfarlan Smith premises in connection with Legionella bacterium risk was on 4 February 2010, as part of a UK-wide programme.
The North British Distillery building, she added, was last proactively inspected on 15 March 2012 to assess management of major accident hazards, but not particularly for Legionella.
MSPs also heard more than 60 sites in the outbreak area had been visited, which included occupation hygenists, visual inspections and assessing records.
The purpose of some of the visits were to exclude certain premises from risk.
When asked how health and safety teams carried out their inspections, Ms Waldron said: "Sometimes it's reactive, sometimes it's after an incident, sometimes it's after a complaint.
"We do have a proactive agenda and we do carry out proactive inspections to certainly high risk sectors."
Also appearing before MSPs was Dr Alison McCallum, director of public health for NHS Lothian and Dr Jim McMenamin, consultant epidemiologist with Health Protection Scotland.
Colin Sibbald, food health and safety manager for City of Edinburgh Council, told the committee he was "confident that we remain well enough resourced to deal with incidents of this matter".