Legionnaires' outbreak: Number of confirmed cases continues to rise with source of infection still unclear

THERE are now 21 confirmed cases of Legionnaires' disease following a deadly outbreak, Health Secretary Nicola Sturgeon has said.
Another 19 people are suspected of having the illness in the Lothian health board area but no more fatalities have occurred since yesterday when one man died, she added.
Twelve of the 21 patients are in intensive care, two have been discharged and the others are either being treated in hospital or in the community.
The number of confirmed cases rose by four from the 17 announced at a previous update this morning. There are also four more suspected cases.
Ms Sturgeon said officials expected to see more cases as the week goes on.
"Given the incubation period for Legionnaires' disease, we would expect to see further cases emerge over the next few days," she told a press conference in Edinburgh, pictured above.
The process of gathering information from the confirmed and suspected cases was continuing, she said.
She added: "As you would appreciate, that's a complex process because it involves, in many cases, dealing with critically ill patients.
"NHS Lothian have brought additional public health staff to bear to make sure that as much information about the behaviours, patterns and the recent histories of these patients is being gathered.
"What we can say is that no link has been identified between these patients other than a general association with the affected area in the south-west of Edinburgh.
"What that does is underline the view that the source of this infection is an outdoor community source and not an indoor-specific source, such as would be the case if it was a spa in a hotel.
"That points, as we have been saying, to cooling towers in the south-west of Edinburgh."
Work around the towers is being led by the city council and the Health and Safety Executive.
Ms Sturgeon said: "Samples have been taken from all of those towers and all of them have been subject to what is called shock treatment which is effectively chemical treatment to deal with the risk of ongoing infection, and there will be sampling over the course of today around these towers."
The process of identifying the infection source was complicated, she said.
"I'm advised by experts that very often with Legionnaires' disease, it's not possible to identify a particular source beyond reasonable doubt so often what is dealt with is a balance of probabilities of where the source is likely to be.
"The process of identifying the source is a complicated one and there are three main strands to that.
"Firstly, epidemiological which is looking at the pattern of cases to try to narrow down to as small an area of possible infection as possible.
"Secondly, microbiological. That's about taking samples, looking at whether Legionella is in existence in a tower and whether it matches a particular strain of Legionnaires' that the patients have.
"Thirdly, it involves the Health and Safety Executive inspection process, looking at the management process around these towers and, if necessary and appropriate, carrying out physical inspections of the towers. And aspects of those processes are ongoing."
NHS Lothian said yesterday the patient who died was in his 50s and had other health conditions. He was being treated at Edinburgh Royal Infirmary.
The majority of confirmed cases are linked geographically to the Dalry, Gorgie and Saughton areas of south-west Edinburgh
Legionella bacteria is commonly found in sources of water, such as rivers and lakes, NHS Lothian said. The bacteria can end up in artificial water supply systems such as air conditioning, water services and cooling towers.
Legionnaires' disease is contracted by breathing in small droplets of contaminated water. Symptoms are mild headaches, muscle pain, fever, persistent cough and sometimes vomiting and diarrhoea. They can begin at any time between two and 14 days after being infected.
The first case in the current outbreak was identified on Thursday May 31.
About half of those who catch the disease will also experience changes to their mental state, such as confusion.
Legionnaires' disease is not contagious and cannot be spread directly from person to person.