Legionnaires’ Disease Outbreaks 1999-2001


Norway, 26 cases, 7 deaths, August 2001 As of 4 September 2001 17 confirmed cases and 2 probable cases of Legionnaires’ disease had been identified in an outbreak on the west coast of Norway, in the city of Stavanger. 2 of the 19 have died. The cases occurred in persons ranging from 30 to 94 years of age — 16 men and 3 women. All the patients had visited a limited area of Stavanger within 10 days of onset of symptoms, which were noticed 26 July in the first patient and 1 September in the latest patient. The investigation has focused on an outdoor decorative fountain and several cooling towers, but a source has not been implicated. Molecular subtyping is underway to compare environmental and clinical isolates. The fountain was shut down and the cooling towers have been disinfected. Source: Eurosurveillance Weekly, 6 September  2001, as reported by Preben Aavitsland and Hans Blystad of the National Institute of Public Health, Oslo, Norway; and Jens Holm of the Medical Health Office, Stavanger, Norway. Update, 3 December 2001: A final report on the outbreak, published in the 29 November 2001 issue of Eurosurveillance Weekly, states that 26 confirmed (by urinary antigen) and 2 probable cases were identified. 21 of the 28 patients were men. 7 of the 28 have died, one of which was one of the two probable cases. The age range of the 28 cases was 16 to 94 years, with a mean age of 54. The age range of those who died was 43 to 94 years, with a mean age of 81. All the patients had been in the same area in the city centre within the incubation period. Legionella pneumophila serogroup 1 was found in water samples collected from the cooling tower of a hotel where three of the patients had been staying. The outlet of the cooling tower was situated five meters above ground, close to a bus terminal. Nine isolates from patients and five isolates from the cooling tower showed similarities and were different from other known Norwegian legionella isolates. [The report did not indicate that the isolates matched exactly.]

Hospital Hot Water Blamed for 18 Cases, 3 Deaths, August 2001 The hot water system at a hospital in Pamplona, Spain is believed to be the source of 18 cases of Legionnaires’ disease that occurred between 29 July and 18 August 2001. Three of the cases were fatal. The cases were confirmed by urinary antigen tests. The victims ranged in age from 39 to 96 years. 16 of the 18 cases occurred in patients who developed pneumonia in the hospital; the other two were in persons who accompanied patients to the hospital. Legionellae were found in the hot water distribution system. Clinical isolates and positive environmental samples have been sent to the national reference laboratory, presumably for subtyping to determine if the Legionella strains found in the hot water system match those detected in patients. Hyperchlorination was carried out during the night of 17 August 2001. Source: Eurosurveillance Weekly, 23 August  2001. Reported by Aurelio Barricarte and Mikel Urtiaga, Regional Health Council of Navarra, Spain, and Salvador de Mateo, National Centre of Epidemiology, Madrid, Spain.

Record-setting outbreak hits Spain, July 2001 The city of Murcia, located about 250 miles southeast of Madrid, has been hit with the most extensive outbreak of Legionnaires’ disease ever recorded. The cases occurred between 26 June and 16 July, 2001. As of 18 July, 745 cases of pneumonia had been diagnosed, of which 315 have been confirmed as Legionnaires’ disease by urinary antigen tests. One-third of the cases were less than 50 years of age. Twelve were admitted to intensive care. Two have died, one 65 and the other 61 years of age. Health authorities speculate that the low death rate is due in part to the quick diagnosis and treatment of the patients. On 7 July 2001, doctors at hospitals in Murcia noticed an unusually large number of patients with pneumonia, so they alerted health officials and started testing for Legionnaires’. The health department determined that 80 percent of the cases came from the same section of town. The area’s water supply and cooling towers were shut off and checked for Legionella. Legionellae were found in 14 cooling towers at 6 buildings. Several towers were positive by PCR, but Legionella pneumophila serogroup 1 has yet to be isolated. Potential sources of contamination were disinfected. Source: News media.   26 October 2001 Update: The source of the biggest Legionnaires’ outbreak to date is still unknown. Legionella strains found in cooling tower samples did not match the ones found in patients. According to Francisco Marques, head of the local health unit, 800 cases of pneumonia have been reported, of which 420 have been confirmed as Legionnaires’ disease. 4 people have died. A report based on data from the Centro Nacional de Epidemiologia Instituto Carlos III, Madrid, estimates that the final number of confirmed cases could reach 650.

Hospital, Paris, 12 cases, 6 deaths, July 2001 It was thought that the Pompidou hospital (Paris) was legionellae-safe after changes to the hot water system were completed in March 2001. Corrective measures had been implemented because of an outbreak of Legionnaires’ disease at the hospital that involved 9 cases and 3 deaths between November 2000 and January 2001. But three additional cases occurred between 29 June 2001 and 9 July 2001, two of which resulted in death, bringing the total to 12 cases, including 6 deaths. Additional measures will be put in place to control legionellae. Source: Financial Times Information, Dow Jones.

Three Cases in Las Vegas, Feb.-June, 2001 The Clark County Health Department reported that three people staying at a Las Vegas timeshare resort contracted Legionnaires’ disease in recent months. The first was in February; the most recent was in June. All three were hospitalized and have since recovered. Only one patient’s specimen was saved and tested. Health officials reported that legionellae were found in a water heater and a rooftop spa, and that the Legionella strain in the environmental samples matched the strain found in the patient who was tested. The property owner voluntarily shut down the floors served by the water heater in which the bacteria were found and relocated about 300 guests. According to health officials, evidence is insufficient to conclude for certain that the three people were exposed to legionellae while staying at the resort. Source: Associated Press

London, 3 cases, May-June 2001 Three confirmed cases of Legionnaires’ disease were associated with central London between 22 May and 3 June, 2001.  All three were men, ranging from 31 to 61 years of age. Two of the men worked in the Portman Square area of London. The third man had been visiting the Portman Square area prior to the onset of illness. The cases were diagnosed by urinary antigen detection. L. pneumophila serogroup 1 was identified in water systems and cooling towers in three buildings in the vicinity.  Control measures have been taken at all three sites and further investigation is under way. Source: Eurosurveillance Weekly Issue 26; 28 Jun 2001.

Legionnaires’ hits Ford a second time, April 2001 Two Ford Motor Company workers became ill shortly after repairing a ruptured pipe on 4 April. The pipe carried pond water to the Dynamometer Building in Ford’s Research and Engineering complex in Dearborn, Michigan. Legionnaires’ disease was confirmed in one of the men; the other showed elevated antibodies to Legionella bacteria. Both have returned to work. Source: The Detroit News.

7 cases, 2 deaths, Melbourne hospital, March-June 2001 Seven cases of Legionnaires’ disease have been associated with a Melbourne (Australia) hospital — four patients, one construction worker at an adjacent site, and two hospital employees. Three of the cases occurred in late March or early April, one in May, and three in early June. Two men who were outpatients have died. One of the hospital employees remains in serious condition but is improving. The hospital CEO said 14 cooling towers at the hospital and surrounding buildings had been tested for Legionella but the bacterium was not detected, which is the reason the hospital waited two months to announce the outbreak. Health authorities have not identified the source. Source: Australian Broadcasting Corporation and news.com.au.

Ford Motor Plant, Ohio USA, 4 cases, 2 deaths, March 2001 Two workers at the Ford Motor plant in Brook Park, Ohio, have died of Legionnaires’ disease, one on 9 March and the other on 16 March. Both were men, ages 53 and 61. Two additional cases were confirmed. The 2,500-employee casting plant was shut down from Wednesday 14 March through Monday 19 March while the (US) CDC conducted an investigation and disinfected mechanical systems. The source of contamination was not pinpointed. Brook Park is located southwest of Cleveland. Ford shut down two sections of another plant on Saturday 24 March after finding Legionella bacteria in water systems. No cases of Legionnaires’ disease were reported at that plant. Source: news media

Melbourne, Australia, 5 cases, 2 deaths, March 2001 Melbourne’s latest outbreak of Legionnaire’s disease has claimed two lives. A 53-year-old man died on 15 March after becoming ill on 6 March. He owned the restaurant located on the ground floor of the 12-story building suspected as the source of contamination. Another man, 43 years of age, died on 5 March. He had visited the same area in February. Three other men, ages 36, 44, and 65, were infected but recovered after hospital treatment. Each had visited the area. High levels of legionellae were found in the building’s cooling tower, although it was a different strain from that which infected the two dead men. Health officials ordered the disinfection of cooling towers in 20 buildings in the vicinity. Source: news.com.au

New hospital in Paris, 4 cases, Dec. 2000 Four individuals contracted Legionnaires’ disease in December 2000 at a hospital in Paris. One of the patients has died, but his death was related to a heart condition, according to the hospital director. The ultramodern 750-bed hospital opened in July. Because the hospital was only partially occupied, officials suspect that stagnant water in unused portions of the plumbing system was the source of contamination. Source: Associated Press, 30 December 2000.

Melbourne, 1 nosocomial case, 3 others, Dec. 2000 A patient who died from Legionnaires’ disease at a hospital in Melbourne on 12 December 2000 had been there for more than two weeks, indicating that the illness was acquired at the hospital (nosocomial). Graham Brown, the head of the Victorian Infectious Diseases Service, located at the hospital, said the patient who died would most likely have been infected by legionellae sprayed from the cooling towers when he went out on a balcony or outside the hospital. However, legionellae were found in only 2 of the hospital’s 12 cooling towers, and at low levels. Three other patients were confirmed as having legionellosis. Two of them were admitted with flu-like symptoms, suggesting that their cases were not nosocomial. Source: www.theage.com.au.

Another community outbreak in Spain–40 cases–Nov. 2000 Forty cases of Legionnaires’ disease were identified in Barcelona from 14-16 November. The victims range in age from 38 to 92. As of Friday, 17 November, four patients were in serious condition. All the victims live in Barceloneta, a neighborhood on Barcelona’s Mediterranean waterfront. City health officials are investigating. Source: The Associated Press.

Rennes, France, 19 cases, 5 deaths, Fall 2000 Between the end of July and 15 Nov 2000, 19 cases of Legionnaires’ disease were reported in Rennes, France, five of whom have died. The French National Reference Centre has reported that the same strain of Legionella pneumophila serogroup 1 was found in seven of the patients. The source of infection is unknown. An investigation is in process. Source: Eurosurveillance Weekly, 20 Dec 2000.

Spain, 70 cases, Sept.- Oct. 2000 Another major outbreak has occurred in Spain, this one in the Valencia region. 70 cases were reported — 43 men and 27 women ranging from 20 to 95 years of age — from 16 September to 8 October 2000. Two patients have died. The investigation has revealed an association with visiting or living in a certain area of the city, but the source of contamination has not been identified. All the cooling towers in the suspected area were disinfected. Intensified surveillance is continuing. Source: Eurosurveillance Weekly, 7 Dec 2000.

Community Outbreak in Spain — 28 cases, 3 deaths — Sept.-Oct. 2000 Twenty-egiht cases of Legionnaires’ disease were identified in Galicia, Spain between 18 September and 1 October 2000–21 men and 7 women, ranging from 30 to 79 years of age. Three have died. An epidemiologic study confirmed that living, working, or walking in the area near a particular hospital was associated with illness. Investigators are focusing on the hospital cooling towers, but no source has been implicated. Source: Eurosurveillance Weekly, 26 October 2000. Reported by Xurxo Hervada, Servicio de Información de Saúde Pública, Dirección Xeral de Saúde Pública, Galicia. Spain, and Rosa Cano, National Center of Epidemiology. Madrid. Spain.

Washington DC schools, two cases, Aug-Oct 2000 On 6 October 2000, DC health officials reported that a case of Legionnaires’ disease contracted by a teacher at Benning Elementary was the second case of the disease involving city school workers recently. The first case occurred in August 2000 in a custodian who worked at Eastern Senior High School. The case at Benning involved a woman of only 24 years of age. She was still recovering in the hospital as of 6 October. Health authorities are investigating the buildings. Source: The Washington Post, 7 October 2000.

Two community cases, Virginia, Sept. 2000 Two cases of Legionnaire’s disease were reported in Covington, Virginia over a two week period. The two individuals live six blocks apart. As of 15 September, both patients were still on lung ventilators. Health Department officials are trying to determine the source of infection. Source: Richmond Times Dispatch, 15 September 2000.

Hospital, UK, 2 cases, July 2000 At least two patients at Leeds hospital have contracted Legionnaires’ Disease and several others are showing symptoms of the illness. A hospital spokesperson said the patients were infected when they stayed in a ward in the Jubilee Building at Leeds General Infirmary in June. He added that a potential source has been identified. An investigation is under way. Source: BBC News Online, 14 July 2000.

Spa bath, Australia, 3 cases, June 2000 A 32-year-old woman who works as a student masseur at the Collingwood Football Club is in critical condition after contracting Legionnaire’s disease. The disease was also confirmed in two men, ages 47 and 48, who were at the club on 3 and 4 June; both have recovered. Environmental tests have indicated the club’s spa bath as the source of the infection. Source: news media.

Public bath, Japan, 14 cases, 1 death, June 2000 Fourteen individuals ranging in age from 58 to 85 contracted an illness with symptoms similar to Legionnaires disease. A 73-year-old man has died and three others are in serious condition. All 14 victims had used the same public bath between early May and 24 June, when it was closed because of the outbreak. Health officials are investigating the Ibaraki bath house for legionellae. Ibaraki is located 63 miles northeast of Tokyo. Source: Associated Press, via Miami Herald  

2 cases in same apartment building, Denmark, Spring 2000 Two individuals who lived in the same block of flats and shared the same hot water system contracted Legionnaires’ disease; the two cases were reported to Copenhagen health officials in the spring of 2000. Legionellae were found in each of the two flats and also in the water circulating line for the entire building. Three serogroups of Legionella pneumophila were found in the water. The serogroup found in one of the patients matched one of the serogroups found in the circulating water. The serogroup found in the other patient matched the serogroup found in both of the flats and in the circulating water. Subtyping indicated identical matches. Water temperatures were increased to 60 C (140 F). One month later, legionellae were still found in water samples, but at lower levels. The water system was then disinfected with chlorine. More samples will be collected in the fall. Source: Eurosurveillance Weekly, 5 October 2000 and Epi-News 2000.

Six cases, Victoria, Australia, April 2000 Another outbreak of legionnaire’s disease has occurred in Victoria. Six cases have been reported at Cobram, west of Albury on the New South Wales border.  All six became ill around the end of April.  An investigation is underway. Cooling towers have been disinfected. Source: Australian Broadcasting Corp, 10 May 2000.

Australia’s largest outbreak, Melbourne Aquarium, April 2000 Updated 21 June 2000: Health authorities have confirmed 101 cases of Legionnaires’ disease among individuals who were at or near the new Melbourne Aquarium between 11 and 25 April. One of the patients was only 23 years of age. A man of only 26 years of age was in critical condition, but has recovered. The disease claimed the lives of two women, ages 79 and 83. Two men, ages 77 and 83, also died of the disease, but health authorities could not confirm that their illnesses were associated with a visit to the aquarium. The outbreak has been blamed on the aquarium’s cooling towers because high levels of legionellae were found in water samples collected shortly after illnesses were identified. The cooling towers were disinfected. The Melbourne Aquarium is now replacing the water cooled air-conditioning system with an air cooled system. Source: news media.

Five cases, Melbourne, March 2000, Office building Five cases of Legionnaires disease have been reported in Melbourne, Australia. Two of the five individuals work in the same office building on Exhibition Street. The other three cases may also be linked to the Exhibition Street area, according to health officials. High levels of legionellae were found in water samples collected from one of the cooling towers at the 222 Exhibition Street office building.  Victoria’s Chief Health Officer Dr Graham Rouch urged city dwellers, office workers and visitors to be alert to signs of the disease.  Source: Sydney Morning Herald and The Age Online.

Hotel, South Wales, Five cases, two deaths, Feb. 2000 Updated 20 April 2000: Five individuals who acquired Legionnaires’ disease each visited the same hotel in South Wales–one in July 1999, one in December 1999, one in January 2000, and two in February 2000. Two of the individuals died of the disease.  The investigation included the hotel’s swimming pool, whirlpool spa, plumbing system, and food display humidifier, along with nearby cooling towers.  Evidence suggests that the food display humidifier was the source of contamination, because the strain of Legionella pneumophila serogroup 1 found in two patients who died from Legionnaires’ disease was indistinguishable from isolates found in the food display humidifier. The humidifier was used to produce mist over food in a refrigerated display unit. The humidifier’s antibacterial filters were missing and its ultraviolet lamp did not work when examined. Source: Eurosurveillance Weekly; reported by Susan Hahné and Roland Salmon, CDSC Wales, and Arun Mukerjee and Bharat Pankhania, Bro Taf Health Authority.

Seven cases, Melbourne suburbs, Feb. 2000 Seven people from Fitzroy and Carlton have contracted Legionnaires’ disease. Chief health officer Graham Rouch said the danger appeared to be in a defined area. “We have to assume, because of this cluster, that we have a community outbreak in that neighborhood,” Dr Rouch said. Health officials are testing cooling towers in the area, but have not identified the source. Source: News.com.au

Trade fair, Belgium, 4 deaths, Nov. 1999 An outbreak of Legionnaires’ disease has been traced to a trade fair in the northern Belgian town of Kapellen. As of 18 November 1999, 80 persons in all have developed clinical symptoms. Legionnaires’ disease has been confirmed by positive urinary tests in 13 of the 80. And 4 of those 13 have died.  Over 60 000 people attended the fair between 29 October and 7 November 1999. Initial investigation suggests that working whirlpool baths exhibited at the show are the most likely source of infection.  Meanwhile, Flemish Minister of Public Health, Mieke Vogels, has banned the exposition of whirlpools at exhibitions as a result of the recent outbreak.  Source: News media, and WHO WER and Epidemiological Bulletin.

Prison, Germany, 4 cases, Sept. 1999 Four prisoners of the JVA Diez penal institution were found to have atypical pneumonias. Physicians suspected legionellosis early in the investigation. Experts detected “large numbers” of Legionella pneumophila serogroup 1 in three shower facilities as well as in other parts of the water system. Two of the contaminated showers had been used by the patients. The shower facilities had been installed only 3 months earlier. Source: Frankfurter Neue Presse and personal correspondence.

Eight cases, Paris, August 1999 Eight persons who had stayed in a small area of the XVth arrondissement of Paris contracted Legionnaires’ disease. One 42-year-old patient died. Dates of onset of illness ranged from 8 to 20 August. Seven patients were men, aged 42 to 78 years. A common building or other source of exposure has not been identified. Source: European Working Group on Legionella Infections (EWGLI), through Eurosurveillance Weekly.

Criminal charges brought against officers of hospital, July 1999 Following an outbreak of Legionnaires’ disease that resulted in 20 cases and 11 deaths, Italian authorities have brought criminal charges against officers of a large hospital in Italy. Source: Deja News. (We have been unable to get additional information on this outbreak.)

Hospital, Maryland, USA, 5 cases, 3 deaths Five cases of Legionnaires’ have been identified at a hospital in Havre de Grace, Maryland since 26 June. Three patients have died. Investigators believe that the hospital’s hot-water system was the source. The system was heat flushed on 2 July. Hospital staff members have contacted about 350 people who were discharged from the hospital since 1 May in order to check for additional cases. Source: Baltimore Sun

Hotel, Belgium, June 1999 Legionnaires’ disease was identified in two patients in a hospital in the Netherlands on or around 17 June 1999. Both patients had stayed in the same hotel while attending a reunion in southern Belgium between 4 and 6 June. Just a few hours later, a third person, who had stayed at the same hotel, was diagnosed with Legionnaires’ in a hospital in Belgium. On 3 July, another Belgian patient with Legionnaires’ disease was reported, making a total of four cases (age range 42 to 86 years) who had stayed at least one night in the hotel between 28 May and 21 June. One of the patients has died. Water and swab samples were taken from taps, showers, and boilers on 21 June. On 25 June, results revealed massive contamination of the whole system with Legionella pneumophila serogroup 1. Legionellae were found in 12 of 13 water samples at a concentration from 10 – 1,000 cfu/ml. PCR fingerprinting revealed that strains collected from water samples matched strains in specimens of two of the patients. The hot water temperatures ranged from 42°C (bottom of boiler) to 46°C (outlets), which would have facilitated contamination. The system was hyperchlorinated on 23 June (two hours at 40-60 mg/L free residual chlorine) and hot water taps were flushed for two minutes. Boilers were drained, scale deposits removed, and cleaned. Samples collected after the disinfection procedure were still contaminated with legionellae at concentrations greater than 10 cfu/ml. On 29 June every tap and appliance was held at 70°C for five minutes. Samples collected after the heat flush were negative. All hotel guests from 15 May onwards were contacted by letter and advised to consult their general practitioner if they developed general or respiratory symptoms. The medical community in Belgium was kept informed through medical newspapers and the incident was reported to the European Working Group on Legionella Infections (EWGLI). Source: Eurosurveillance Weekly. Reported by Olivier Ronveaux, European Programme on Intervention Epidemiology Training, Sophie Quoilin, André Sasse, Frank Van Loock, Marc Struelens, and A. Moreau, Communauté française, Belgium.

Spa resort, Spain, May 1999 Two confirmed and six suspected cases of Legionnaires’ disease were identified among people who were staying at a natural spa resort in the province of Guipúzcoa between 1 and 22 May 1999. The first case was diagnosed on 20 May. Local health authorities have established that 432 persons were staying in the resort during the period under investigation. 35 persons were being investigated. The spa resort was closed on 22 May. Legionella pneumophila serogroup 1 has been recovered from water samples taken in the spa resort. Source: Eurosurveillance Weekly. Reported by Rosa Cano, Centro Nacional de Epidemiología, Madrid, and Txema Arteagoitia, Dirección de Salud Pública del País Vasco, Vitoria, Spain.  

Flower show, 242 cases, 28 deaths, The Netherlands, Mar. 1999 Updated 28 June 1999: Dutch health authorities have confirmed that 242 people who visited a large flower show near Amsterdam became ill and 28 died. Seemingly healthy people were among the victims. Legionnaires’ disease has been confirmed or is considered probable in 192 of the cases and 21 of the deaths. Legionnaires’ could not be identified in the other 50 cases and 7 deaths. The public health laboratory found legionellae in a whirlpool spa that was on display at the show. The strain of legionellae found in the whirlpool was identical to that found in some of the patients. Source: news media and NL health ministry

Two deaths at a hospital in Wales, Jan. 1999 A 36-year-old taxi driver who had been on a life support machine for 17 days at a hospital in South Wales died of Legionnaires’ disease. Just days later, a 59-year-old woman was admitted to the same hospital; she died of Legionnaires’ disease after a week-long stay. She had been in critical condition. Health officials are looking for the source of infection. Source: News media

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