Two people have died and another 94 have been struck down by confirmed or suspected cases of legionnaires’ disease, but one expert today warned that figure was likely to be only the “tip of the iceberg” as hundreds more may have suffered symptoms after becoming infected.
With health chiefs confident that the outbreak is under control, they are now turning their attention to initiating a huge retrospective investigation in an attempt to discover the full scale of infection in communities.
But they have come under fire from people who have suffered with legionellosis infections, who said the risk of developing milder symptoms was not publicised well enough as the crisis unfolded.
Elaine Walker, of Murray- field, has been told by her doctor that she has been ill with Pontiac fever – an illness caused by the legionella bug.
“The public are being misled as to the numbers of people affected,” she said. “I personally know five people who have had Pontiac fever and I know of another ten.”
Stephen Jones, who attended the Hearts cup final parade in Gorgie, said he initially discounted the possibility that his illness had been caused by legionella because the published figures were so low.
He believes the authorities deliberately downplayed the seriousness of the outbreak.
He said: “I saw the number of confirmed and suspected cases and thought the probability was so minute that it couldn’t be that.”
He was later told that he had almost certainly suffered a legionella-related illness.
The figures released by the Scottish Government throughout the crisis relate only to confirmed or suspected legionnaires’ disease cases. No estimate had been put on how many have suffered with milder legionella infections.
Typically, around one to two per cent of people who are directly exposed to the legionella bug develop full-blown legionnaires’ disease.
Using the one to two per cent “attack rate” and the 49 confirmed cases as a guide, it can be estimated that between 2450 and 4900 people breathed in the bug.
As up to five per cent of those who are directly exposed typically become ill, up to 245 of those could have been expected to develop symptoms.
The figures would almost double if all of the suspected legionnaires’ disease cases became confirmed, though NHS Lothian said calculating the number of sufferers was “not scientific”.
Allen Wilson, a legionnaires’ disease expert, said the confirmed or suspected cases were likely to be the “tip of the iceberg” in terms of the total number of people affected.
He said: “They would have had the hypochondriacs galloping to the doctors but there’s other people who might have had a dose of Pontiac fever and preferred to get over it in their own way.”
During the legionnaires’ crisis, around 500 more patients than normal sought out-of-hours care in affected areas, GPs surgeries were stretched and 1000 calls were made to a dedicated NHS helpline.
Dr Duncan McCormick, consultant in public health medicine for NHS Lothian, said: “The majority of consultations in the community for suspected legionella infection have come back with negative results.
“We are carrying out a number of investigations as part of the ongoing management and follow-up of this outbreak.”
Warning signs of a potential killer
Legionellosis is an infection with legionella bacteria with mild or severe symptoms.
If symptoms of legionellosis are mild then it is sometimes referred to as Pontiac fever.
If symptoms are very severe with pneumonia, then it is known as legionnaires’ disease. These two variations do not often occur together.
Usually for an outbreak of legionnaires’ disease, less than five per cent of people potentially exposed to the bacteria become ill.
There are typically between 15 and 40 cases of legionnaires’ disease each year in Scotland, with half linked to foreign travel.
WHY TESTING ALL PATIENTS RULED OUT
On June 11, with legionnaires’ disease cases rising daily, GPs were told to only test patients with suspected pneumonia for the legionella bug. Patients with signs of a legionella infection, but no sign of pneumonia, were prescribed antibiotics, but were not tested for the disease.
Dr Duncan McCormick said: “At the beginning of the outbreak, a large number of individuals presented to GPs with vague or mild symptoms and were tested, with very few tests yielding positive results.”