Published Date: 2012-06-05 12:43:34
Subject: PRO/EDR> Legionellosis - UK (02): (Scotland)
Archive Number: 20120605.1156972
LEGIONELLOSIS - UK (02): (SCOTLAND)
A ProMED-mail post
ProMED-mail is a program of the
International Society for Infectious Diseases
Date: Mon 4 Jun 2012
Source: The Scottish Sun [edited]
NHS [National Health Service] Lothian said they had 4 confirmed and another 4 suspected cases of the illness in Edinburgh. 4 men aged 39, 48, 60, and 63 [years] have the disease while 2 49-year-old women and 2 men aged 63 and 88 [years] are also being monitored. 5 were being treated at Edinburgh's Royal Infirmary, one was at the capital's Western General Hospital, while 2 were in St John's in Livingston. All are in intensive care or high dependency units.
Environmental health officers are treating cooling towers in the south west of the city as a "precaution". Last night [3 Jun 2012] NHS Lothian public health chief Donna Milne said: "We have 4 confirmed cases of legionnaires' disease. Anybody who develops symptoms should contact NHS 24 immediately or go to their GP."
[Byline: Paul Thornton]
ProMED-mail from HealthMap alerts
Date: Mon 4 Jun 2012
Source: BBC News Edinburgh, Fife & East Scotland [edited]
Another 2 cases of legionnaires' disease have been confirmed in Edinburgh. It brings the number of people known to have contracted the illness following an outbreak in the city to 6. They all are being treated in intensive care or in high dependency units. 4 others are suspected of having the disease.
Industrial water-cooling towers in the south west of Edinburgh, where all of the cases have come from, have been identified as a potential source. Samples have been taken from 4 towers and sent for analysis. All 10 are linked geographically to the Dalry, Georgie [? Gorgie], and Saughton areas. The 1st case was identified on Thu 28 May .
The _Legionella_ bacteria are commonly found in sources of water, such as rivers and lakes. It can end up in artificial water supply systems, including air conditioning systems, water services, and cooling towers. The health board has reassured residents the source is not thought to be linked to domestic water supplies.
Dr Duncan McCormick, consultant in public health and chair of the incident management team, said: "Investigations into the possible source of this outbreak are on-going and we continue to urge anyone who develops symptoms of Legionnaires' disease to contact NHS 24 or go to their GP."
The source of the outbreak was being investigated by the city council's environmental health department and the Health and Safety Executive. Colin Sibbald, environmental health manager at the City of Edinburgh Council, said: "It was identified that the potential source was most likely from some form of wet cooling tower connected to air conditioning systems or processes. Environmental health officers identified 2 premises in the west of the city that had these cooling towers. Samples were taken from their towers and have been sent for analysis." He added: "This morning, 2 further premises have been identified in the west of the city, which officers have also visited to take samples. Those responsible for the maintenance of the cooling towers at these 4 locations have been advised to carry out additional chemical treatment of the water within the cooling system as a precautionary measure." Other possible sources were not being ruled out.
Legionnaires' disease is not contagious and cannot be spread directly from person to person. It is contracted by breathing in small droplets of contaminated water. Symptoms include mild headaches, muscle pain, fever, a persistent cough, and sometimes vomiting and diarrhoea.
[Recently ProMED-mail posted a report of 6 cases of legionnaires' disease occurring in Scotland over the past 5 years due to _Legionella longbeachae_ and associated with the use of compost (Legionellosis - UK: (Scotland) L. longbeachae, compost, fatal 20120529.1148827). However, the news reports above fail to specify the species of _Legionella_ in the 6 more recent confirmed cases of legionnaires' disease.
Legionellosis is an infectious disease caused by a Gram negative bacillus of the genus _Legionella_, most commonly _Legionella pneumophila_. Legionnaires' disease is the acute pneumonic form of the disease; more than 70 percent of cases are due to _L. pneumophila_ serogroup 1, except in Australia and New Zealand, where _L. pneumophila_ serogroup 1 has accounted for only 45.7 percent of cases of community-acquired legionellosis, and _Legionella longbeachae_ has accounted for 30.4 percent of cases (Yu VL, et al: Distribution of _Legionella_ species and serogroups isolated by culture in patients with sporadic community-acquired legionellosis: An international collaborative survey. J Infect Dis. 2002; 186(1): 127-8. Available at http://www.legionella.org/lp_distribution.pdf). In addition to Australia and New Zealand, cases of legionnaires' disease due to _L. longbeachae_ have been reported in other countries including the USA (ProMED-mail post Legionellosis, potting soil - USA: May-Jun 2000 20000904.1503), Japan (Koide M, Saito A, Okazaki M, et al. Isolation of _Legionella longbeachae_ serogroup 1 from potting soils in Japan. Clin Infect Dis 1999; 29(4): 943-4; available at http://cid.oxfordjournals.org/content/29/4/943.long; and http://www.ncbi.nlm.nih.gov/pubmed/17929472), and the UK (ProMED-mail post Legionellosis, hotel - UK (02): (Scotland) background 20110328.0974).
Unlike _L. longbeachae_, which is found predominantly in soil and potting mix (Ross IS, Mee BJ, Riley TV: _Legionella longbeachae_ in Western Australian potting mix. Med J Aust 1997; 166(7): 387), _L. pneumophila_, is found in natural aquatic bodies, including rivers, lakes, and thermally polluted waters. Presumably, because the Scottish authorities are pursuing a water source in the 6 confirmed and 4 suspected cases of legionnaires' disease, _L. pneumophila_ has been implicated in some of the patients in the news reports above.
Other outbreaks of legionnaires' disease due to _L. pneumophila_ in the UK have been associated with overseas travel (ProMED-mail post Legionellosis - UK ex Greece, travelers, alert 20111008.3021) or hotel stay (ProMED-mail post Legionellosis, hotel - UK (03): (Scotland) 20110408.1100). Such a history is not specified for the cases in the news reports above.
Genotyping of patient and environmental isolates has become a helpful tool to establish transmission pathways. The predominance of one genotype of _Legionella_ isolated from patient specimens would suggest transmission from a common source. Because _Legionella_ may be found in environmental samples without linkage to any cases of legionellosis, the actual causative infectious reservoir can be confirmed by matching the genotype of clinical and environmental isolates (see http://www.ncbi.nlm.nih.gov/pmc/articles/PMC86783/ and http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2730281/). However, clinical isolates are often not available because the clinical diagnosis of legionnaires' disease is commonly made on the basis of serology or the _Legionella_ urinary antigen test, and not culture of patient specimens.
Lothian is a region of the Scottish Lowlands that includes Edinburgh City. For a map of this region, see http://en.wikipedia.org/wiki/Lothian. Saughton is a suburb to the west of Edinburgh. Dalry and Gorgie are to the immediate east of Saughton close to the center of Edinburgh (http://en.wikipedia.org/wiki/Dalry,_Edinburgh). For a map showing Saughton, Dalry, and Gorgie, see http://www.maplandia.com/united-kingdom/scotland/scotland/city-of-edinburgh/gorgie/.
Scotland can be located in the interactive HealthMap/ProMED-mail map at http://healthmap.org/r/2wlL. - Mod.ML]