This is a list of Legionnaires' disease outbreaks; Legionnaire's is a potentially fatal infectious disease caused by gram negative, aerobic bacteria belonging to the genus Legionella. The first reported outbreak was during a Legionnaires Convention at The Bellevue-Stratford Hotel in Philadelphia in 1976.
An outbreak is defined as two or more cases where the onset of illness is closely linked in time (weeks rather than months) and in space, where there is suspicion of, or evidence of, a common source of infection with or without microbiological support (i.e. common spatial location of cases from travel history).
Worldwide listings by year 1960s Year City Venue Source Cases Deaths Fatality rate Notes1965 Washington, D.C., United States St. Elizabeths Hospital Unknown 94 16 17% The outbreak occurred in 1965, but was not identified as legionnaires' disease until saved blood serum was exposed to bacterial samples from the 1976 Philadelphia Legionnaires' disease outbreak.
1970s Year City Venue Source Cases Deaths Fatality rate Notes1973,1977 Benidorm, Spain Hotel Rio Park Shower pipes at least 4 unknown The first outbreak in Hotel Rio Park occurred in 1973, four tourists died, but at the time it was not recognized as Legionnaires' disease until a subsequent outbreak in the same hotel in 1977.1976 Philadelphia, Pennsylvania, United States 1976 Philadelphia Legionnaires' disease outbreak Air conditioning 15.4% This was the first recognized outbreak of legionellosis, although earlier cases of legionellosis were later discovered to have occurred as far back as 1947. The Philadelphia outbreak, however, had the highest death rate.1978 Memphis, Tennessee, United States Baptist Memorial Hospital-Memphis (1912–2000) air-conditioning cooling tower 44 1978 Memphis Legionnaire's Disease Outbreak1979 Melbourne, Australia light industrial building medium-sized evaporative condenser 1979 Ballarat, Australia psychiatric hospital shower water system
1980s Year City Venue Source Cases Deaths Fatality rate Notes1985 Wollongong, Australia social club building small cooling tower 1985 Stafford, England Stafford District Hospital Air conditioning 16% In April 1985, 175 patients were admitted to the District or Kingsmead Stafford Hospitals with chest infection or pneumonia. A total of 28 people died. Medical diagnosis showed that Legionnaires' disease was responsible and the immediate epidemiological investigation traced the source of the infection to the air-conditioning cooling tower on the roof of Stafford District Hospital.1986 Adelaide, Australia community small cooling tower at hospital 1987 Wollongong, Australia shopping centre small cooling tower at a shop 1988 Adelaide, Australia community potting mixes 1988 Westminster, England BBC headquarters cooling tower at Broadcasting House 1989 Sydney, Australia bowling club small cooling tower 1989 Burnie, Australia community small cooling tower at hospital
1990s Year City Venue Source Cases Deaths Fatality rate Notes1992 Sydney, Australia shopping centre small cooling tower 1994 Sunshine Coast, Australia holiday apartment unit private spa pool 1995 Sydney, Australia shopping centre small cooling tower at hospital 1996Chrisitansburg, Virginia, United StatesDepartment StoreHot tub232 1999 Bovenkarspel, Netherlands 1999 Bovenkarspel legionellosis outbreak Hot tub 10% In February and March 1999, an outbreak occurred in the Netherlands during the Westfriese Flora flower exhibition in Bovenkarspel, North Holland. 318 people became ill and at least 32 people died. There is a possibility that more people died from it (which might make it the deadliest recorded outbreak), but these people were interred before the Legionella infection was recognized. The source of the bacteria was a hot tub in the exhibition area.
2000s Year City Venue Source Cases Deaths Fatality rate Notes2000 Melbourne, Australia Sea Life Melbourne Aquarium Cooling tower 3.2% In April 2000, an outbreak of Legionella pnemophila serogroup 1 occurred in Melbourne, Australia. The outbreak resulted in 125 confirmed cases of Legionnaire's disease, with 95 (76%) hospitalised. It is reported that 4 died from the outbreak. The investigation traced the source of the infection to the cooling tower at the newly opened aquarium. Since this outbreak, legionella infection statistics are required to be reported by the state government as a notifiable disease. Regulations were introduced by the state to control legionella in 2001.2000 Vizela, Portugal Public square Decorative fountain 0% In August 2000, an outbreak of Legionnaires' disease occurred in Vizela, Northern Portugal. A total of 11 persons with Legionnaires' disease were admitted to the hospital. There were no fatalities. All patients had been in the main square of Vizela in the night of August 11–12, 2000, where the annual festivities of the municipality were being held. Investigators traced the source of the outbreak to a decorative fountain located in the square.2001 Murcia, Spain Hospital Cooling Towers+ 0.8% The world's largest outbreak of Legionnaires' disease happened in July 2001 with patients appearing at the hospital on July 7, in Murcia, Spain. More than 800 suspected cases were recorded by the time the last case was treated on July 22; 636–696 of these cases were estimated and 449 confirmed (so, at least 16,000 people were exposed to the bacterium) and 6 died. A case-fatality rate of approximately 1%.2002 Barrow-in-Furness, England 2002 Barrow-in-Furness legionellosis outbreak Air conditioning 4.1% In 2002, Barrow-in-Furness in England had an outbreak of Legionnaires' disease. Six women and one man died as a result of the illness; another 172 people also contracted the disease. The cause was found to be a contaminated cooling tower at the town's Forum 28 arts centre. Barrow Borough Council later became the first public body in the UK to be charged with corporate manslaughter but were cleared. They were, however, along with architect Gillian Beckingham, fined for breaches of Health and Safety regulations in a trial that ended in 2006. 2003-2004 Pas-de-Calais, France Petrochemical plant Cooling tower 20.93% This was the worst outbreak of Legionnaires in French history. 2004 Zaragoza, Spain Hospital Cooling tower 26% Five out of seven of the fatalities were above the age of 50. 2005 Toronto, Canada Seven Oaks Home for the Aged Cooling tower 16.5% In late September, 2005, 127 residents of a nursing home became ill with Legionella pneumophila. Within a week, twenty-one of the residents had died. Culture results at first were negative. The source of the outbreak was traced to the air-conditioning cooling towers on the nursing home's roof. 2005 Fredrikstad, Norway Factory Air scrubber 9.7% At least 103 people became ill and ten died from Legionnaires' disease caused by bacteria growing in an air scrubber of a nearby factory.2007Jastrzębie Zdrój, Poland2nd District Specialist Hospital, Ophthalmic WardWater system4375%In January 2007 in the 2nd district specialist hospital in Jastrzębie-Zdrój two patients on the ophthalmic ward unexpectedly died. It was noted that they suddenly had a high fever, coughs and hallucinations. First they were transferred to the infectious diseases ward for some hours with a suspicion of pneumonia, later they were transferred to intensive care. Tests showed that both patients had legionellosis. The disease proved to be the cause of death of one of the patients, the other also had circulatory failure. The bacteria responsible for legionellosis was found in four patients from this hospital. In total the outbreak resulted in three deaths2008 New Brunswick, New Jersey, United States Saint Peter's University Hospital Drinking water 33.3% Chlorination in the water system had dropped below effective levels.
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