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Legionella is a Gram negative bacterium, including many species that cause legionellosis or Legionaires' disease, most notably L. pneumophilia. At least 46 species and 70 serogroups have been identified. On the side-chains of the cell wall are carried the bases for the somatic antigen specifity of these organisms. The chemical composition of these side chains both with respect to components as well as arrangement of the different sugars determines the nature of the somatic or O antigen determinants, which are such important means of serologically classifying many Gram-negative bacteria.

At least 14 different serovars of L. pneumophila have been described as well as several other species being subdivided into a number of serovars. Sera have been used both for slide agglutination studies as well as for direct detection of bacteria in tissues using fluorescent-labelled antibody. Specific antibody in patients can be determined by the indirect fluorescent antibody test. ELISA and microagglutination tests have also been successfully applied.

Legionella pneumophila is non-acid, fast non-capsulated rods, aerobic and do not hydrolyse gelatin or produce urease. They are non-fermentative. L. pneumophila is neither pigmented nor does it autofluoresce. It is oxidase- and catalase- positive, and produces beta-lactamase.

L. pneumophila is an intracellular pathogen. The internalisation of the bacteria is enhanced by the presence of antibody and complement. A pseudopod coils around the bacterium in this unique form of phagocytosis. Once internalised, the bacteria surround themselves by a membrane-bound phagolysosome. This becomes a vesicle, within which the bacteria multiply. They produce a 39kDa metalloprotease into culture fluids, which is cytotoxic for some cultured tissue culture cells.

 Special Note

Legionella is a bacteria not a virus, it has an incubation period now of up to 20 days.

Two recent outbreaks in France and Norway it was stated that the legionella travelled 12 and 17 Kilometres

http://members.dodo.net.au/~jamgreen/legionellose_france.index.htm

http://www.q-net.net.au/~legion/legionella_norway.htm

Unidentified illness kills four Toronto seniors

2 October 2005

Toronto

Public health officials are investigating the deaths of four people from a "typical respiratory illness" at an east-end senior's residence, but say the outbreak is not SARS.

The four victims were residents at the Seven Oaks Home for the Aged in the city's east end, said Dr. Barbara Yaffe, Toronto Public Health's director of communicable disease control.

"We know from the testing that's been done so far that this is not influenza, we know this is not SARS, we know this is not avian influenza," said Dr. Allison McGeer, infectious disease consultant at Toronto's Mount Sinai Hospital.

"There are many other viruses it could be ... and the Ontario Public Health lab is working very hard on identifying which one of those viruses it might be."

The unidentified illness has affected 68 residents and five employees at facility.

Three of the victims died at the home while the fourth died in hospital, she said.

Dr. Yaffe said all of the four victims had severe pre-existing medical conditions. Two were in their 90s, another in the late 70s, and the fourth in the 50s.

She said outbreaks are typical but this one set off alarms because of its severity.

"We get hundreds of outbreaks every year, however in this situation we do have a particularly serious outbreak," Dr. Yaffe said.

She said 15 people have been admitted to hospitals in the area, but are not being quarantined.

"There is no quarantine necessary for this," Dr. Yaffe said, and emphasized that there was no threat to the greater public.

The speed with which the illness spread led Dr. McGeer to speculate whether a presence of bacteria within the home contributed to the outbreak.

Dr. Yaffe also added that while this outbreak was serious, it was not the worst in recent memory. Last year, 11 people died after an outbreak at a Cobourg, Ont., nursing home, she said.

CFTO News reported that the first signs of the most recent illness were detected Tuesday, but no residents were taken to hospital until Saturday night.

Dozens of family members were prevented from entering the home Saturday.

Emergency room staff at Centenary Hospital donned gowns and masks Saturday as a procedural precaution — a standard practice in Ontario hospitals after the SARS outbreak in 2003.
Either people haven't been following precautions that we are supposed to follow now for all people with fever or respiratory illness . . . or alternatively, somebody had brought it in from the community to the nursing home and they weren't really that sick from it," infectious disease specialist Dr. Neil Rau said.

Symptoms of the illness include fever, cough, runny nose, and malaise, Dr. McGeer said.
She said the best way for the public to prevent such outbreaks occurring is to wash their hands thoroughly and frequently.

October 3, 2005
Media Advisory - Respiratory illness update

Toronto Public Health continues to investigate the outbreak of respiratory illness at Seven Oaks Home for the Aged, Dr. David McKeown, Toronto's Medical Officer of Health, said today.

The investigation is being carried out in conjunction with the Ministry of Health and Long-Term Care, the Ontario Public Health Laboratory, the Coroner's Office and affected hospitals. The outbreak began September 25, 2005.

Dr. McKeown reported the following update:
 

Date: Tue, 4 Oct 2005 13:06:00 -0400
From: Jeannette Macey <Jeannette_Macey TA phac-aspc.gc.ca & Susan Squires, (Public Health Agency of Canada) & the Ontario Ministry
of Health and Long Term Care


By way of further follow-up to the 3 Oct 2005 posting entitled "Undiagnosed respiratory deaths - Canada (ON): RFI", I am providing the following summary from the Ontario Ministry of Health and Long Term Care and the Public Health Agency of Canada.

The province of Ontario has in place ongoing surveillance for febrile respiratory illnesses in hospitals and residential institutions. The syndrome
under surveillance is referred to as febrile respiratory illness or FRI. As a result of this ongoing surveillance, outbreaks are regularly detected,
especially during the influenza/respiratory virus season, which we are now entering in Canada. The 1st outbreak of laboratory-confirmed influenza for 2005-2006 was reported in a long-term care facility (LTCF) elsewhere in the country last week, and other common respiratory viruses are circulating as well. (see Canada's weekly FluWatch surveillance report at:
<http://www.phac-aspc.gc.ca/fluwatch/index.html)>)

The important summary points re: public health significance of this outbreak are that preliminary laboratory results are negative for key respiratory
pathogens of concern (including influenza viruses, novel influenza viruses, SARS as well as other common respiratory pathogens); the attack rate and mortality rate are not out of the expected range for LTCF outbreaks, and finally the outbreak appears to be waning (no new cases in recent days). Further laboratory investigations are ongoing.

The current outbreak of FRI was identified in a Toronto nursing home on Tue 27 Sep 2005.  A FRI case is defined as a resident, staff member or visitor with sudden onset of fever with malaise and/or anorexia, with or without runny nose and congestion or cough.

To date, 67/249 (27 percent) residents and 8/290 (3 percent) staff members meet the case definition (these numbers are subject to change); 23 (34
percent) resident-cases and 1 (13 percent) staff-case have been hospitalized. 6 (9 percent) case-residents have died.  Additionally, 3 visitors have been
identified who meet the case definition; 2 of these have been hospitalized and investigated.

Cases are rapidly improving upon initiation of antibiotic therapy. Despite comprehensive preliminary testing for bacterial and viral respiratory
pathogens, no organism has yet been identified. Lung biopsy specimens from deceased cases are undergoing testing. Several prevention and control
strategies have been implemented, and the outbreak appears to be waning, with many cases now improving. There have been new cases reported since midnight 2 Oct [2005]. The risk of transmission to the general public would appear to be minimal.

In terms of the larger picture with respect to the respiratory [illness] season in Canada, we are likely to see many reports of nursing home and other
institutional outbreaks. As is often the case, a proportion of these outbreaks will not have any identifiable etiologic agent. Using increasingly
sophisticated molecular testing techniques, laboratory scientists are able to detect and identify previously unrecognizable viruses, e.g. new coronaviruses and parvoviruses etc. As a result, appropriate risk assessment is an important accompaniment to these reports, especially given the current very wide coverage of respiratory illnesses/outbreaks in the media.


Jeannette Macey
A/Head of Disease Surveillance
Immunization and Respiratory Infections Division (IRID)
Division d'immunisation et des infections respiratoires (DIIR)
Public Health Agency of Canada (PHAC)
Agence de sante publique du Canada (ASPC)
Building #6, AL 0602D, Tunney's Pasture
Ottawa, Ontario K1A 0L2
<Jeannette_Macey TA phac-aspc.gc.ca>

Respiratory illness update

    TORONTO, October. 4 
The respiratory illness at Seven Oaks Home for the Aged has resulted in additional deaths among ill residents, but the
outbreak remains under control, Dr. David McKeown, Toronto's Medical Officer of Health, reported today.

    Dr. McKeown provided the following update:

    -  Since yesterday there have been four additional deaths,for a total of ten in the outbreak.

    -  The outbreak has so far affected a total of 70 residents,12 employees and two visitors at Seven Oaks.

    -  40 residents from Seven Oaks have been admitted to hospital.

    -  The majority of cases are improving but some have worsened as the illness takes its course.

    -  Testing continues to determine the cause of the illness.

    -  Hospitals and their emergency rooms are operating normally.

    "Although the condition of some ill residents has worsened and unfortunately four more have died, others are improving and we are confident
this outbreak is under control," said Dr. McKeown.   

October 5, 2005
Media Advisory - Respiratory illness update

The respiratory illness at Seven Oaks Home for the Aged has resulted in six additional deaths among ill residents, Dr. David McKeown, Toronto’s Medical Officer of Health, reported today.

“The six new deaths are not new cases. All of these elderly individuals had been previously identified as cases and had underlying medical conditions,” Dr. McKeown said. “There have been no new reported cases in the last 24 hours.”

Dr. McKeown provided the following update:

5 October 2005

Ten people have died from a mystery viral outbreak at a Toronto nursing home and another 40 are in hospital, public health officials said on Tuesday as they raced to contact anyone who visited the home recently.

The outbreak, an unidentified respiratory virus, has sparked memories of the SARS outbreak two years ago that killed 44 people in Canada's largest city.

But health officials said the latest outbreak, which was first detected on September 25, is under control although they warned that more deaths could be expected.

Four new deaths were added to the toll on Tuesday, all of them elderly residents at the Seven Oaks Home for the Aged. All of the dead were aged between 50 years to 95 years.

"Although the condition of some ill residents has worsened and unfortunately four more have died, others are improving and we are confident this outbreak is under control," said David McKeown, Toronto's medical health officer.

Health officials have ruled out SARS, avian flu and influenza and are awaiting lab results, reports the Reuters.

Six more seniors dead from mystery T.O. outbreak

Six more residents of a Toronto seniors' residence home are dead from a mystery respiratory illness, raising the death toll to 16.

"It's obviously something new," infectious disease specialist Dr. Neil Rau  told CTV News. "It's either a new virus, or it's a play on an old virus that's become a little more virulent to the point of causing very significant disease in elderly people."

Toronto's medical officer of health, Dr. David McKeown, said there have been no new reported cases in the last 24 hours.

Public health officials say the cause for the outbreak at the Seven Oaks Home for the Aged in the city's east end remains unknown but that they are continuing testing. However, they maintain that the situation is under control.

"I think that if in a week we can't figure this out, it's time to get some international help," Dr. Rau said.

"What we are seeing is a pretty virulent pathogen that is causing this outbreak," said Dr. Donald Low, medical director of the public health laboratories branch in the Ministry of Health, appearing on CTV Newsnet.

Low has analyzed tissue samples from one of the victims who just died. Health officials have have ruled out influenza, avian flu, SARS (severe acute respiratory syndrome) and Legionnaires' disease.

"So our task right now is to find out...what the cause is," Low said. "And that's what we are doing... literally working day and night with clinical specimens to find out what is causing this."

A total of 38 people are in hospital; 34 of them are residents, two are staff, and two are visitors to Seven Oaks.

Since the outbreak began on Sept. 25, 70 residents, 13 employees and five visitors have become ill.

"The majority of cases are improving but some have worsened as the illness takes its course," a statement released by the city's public health officials said Wednesday.

"What is reassuring, despite the fact that the number of deaths are going up is that the number of new cases per day is dropping," said Dr. Rau. "We have to watch a little longer, but it looks like that is a favourable trend."

Ontario Health Minister George Smitherman urged caution, saying there is no evidence to suggest the outbreak has spread beyond the seniors' home.

Smitherman noted Wednesday that respiratory illnesses afflicting vulnerable patients such as seniors are not uncommon.

"These are not circumstances that are new," he said. "We're struggling with circumstances like this always in the institutional environment."

Dr. Low agreed, saying such outbreaks have been around for decades.

"It is just now that we have the technology that we can actually identify them, and hopefully actually tell you what is causing them," he said.

Anxiety over the outbreak has been aggravated by fears of SARS in Toronto, a city still reeling from the effects of the respiratory illness.

In 2003, two SARS outbreaks in the Toronto area killed 44 and sickened hundreds. Worldwide, more than 8,000 people contracted the illness and 774 people died.

Meanwhile, the Greater Toronto Hotel Association has released a confidential memo to hotels in the city, urging them to be on alert that visitors and foreign media may pick up on the story and draw unwarranted comparisons to the SARS outbreak.

Among a list of bulleted recommendations, officials are warned that speaking out on the issue may make them appear "defensive."

"The only threat here is if people get carried away with hysteria (or if the outbreak escalates significantly, but there appears no reason to suspect it will)," the memo says.'

"We can inform anyone who asks that we are monitoring the situation closely. Of course we can't appear to be dismissing it out of hand.

"But the biggest threat to tourism is not a respiratory outbreak, it's a hysteria outbreak. That's what we need to contain. We certainly do not want to make any comments that refer to SARS or "last time."

Hotel officials are urged to limit any comment to the theme: "Toronto is one of the safest cities in the world, and that's as true today as ever."

The memo follows in the footsteps of increasingly intense media coverage on the outbreak.

The city's tourism and hospitality industry was hard hit by the SARS crisis after the World Health Organization put Toronto on a list of areas fighting SARS in 2003, thus driving away potential tourists leery of becoming infected

Mystery Illness Kills 16 People In Toronto

Health minister urges Ontarians to get flu shot after seniors' home outbreak at 15:05 on October 5, 2005, EST.

5 October 2005

TORONTO
A deadly outbreak of a respiratory illness at a Toronto seniors' home is a grim but timely reminder that Ontario residents should get their free flu shot this year, Health Minister George Smitherman said Wednesday.

The mysterious illness at the Seven Oaks Home for the Aged has killed 10 people and affected more than 80 others, but Smitherman said he's confident the outbreak is contained and under control. Even though the cause of the outbreak is unknown, Smitherman said it highlights the need for people to take necessary precautions to stay healthy.

"It really does help to remind people that as relates to the flu, it's serious, and accordingly we really need to encourage people to take advantage of those free flu vaccines," he said, noting that not all provinces offer free flu shots to residents as Ontario does.

People should also remember that a simple act like proper handwashing can also prevent the spread of illnesses, Smitherman said.

The minister said there's no evidence to suggest the outbreak has spread beyond the Seven Oaks home, but he noted that respiratory illnesses are common among vulnerable groups of people like seniors.

"These are not circumstances that are new," he said. "We're struggling with circumstances like this always in the institutional environment."

"But I do feel that lessons have been learned from SARS have been well-applied here."

The outbreak is being carefully monitored by public health officials, Smitherman said.

"Of course we're monitoring it vigorously," he said. "I'm very confident that the steps that have been taken are the appropriate ones."

Date: Fri, 7 Oct 2005 09:27:16 -0400
From: Susan Squires <susan_squires1 TA phac-aspc.gc.ca>
Source:  Jeannette Macey, Susan Squires, Ottawa, Public Health Agency of  Canada, & Erika Bontovics, Toronto, Ontario Ministry of Health and Long-term
Care [edited]


Since 2 Oct 2005, no new cases of FRI (febrile respiratory illness) have been identified in connection with a respiratory outbreak in a Toronto nursing home. A FRI case is defined as a resident, staff member or visitor with sudden onset of fever with malaise and/or anorexia, with or without runny nose and congestion or cough.

In total, 93 cases, including 16 deaths, have been identified to-date.  The case breakdown is as follows:  70 residents, 16 staff and 7 visitors.  All deaths have occurred in residents of the nursing home.  Cases are rapidly improving upon initiation of antibiotic therapy.

Autopsy specimens were received from 7 patients through the coroner's office and tested by the Central Public Health Laboratory in Toronto.  All were tested for _Legionella pneumophila_ by DFA and culture. To-date specimens from 3 deceased patients are positive for _L. pneumophila_.  Culture results on the other 4 deceased patients are pending.
 

A masked health care worker greets an unidentified women who came to the front doors of Seven Oaks Home for the Aged.

As a result of this ongoing surveillance, outbreaks are regularly detected, especially during the influenza/respiratory season, which we are now entering in Canada.  The 1st outbreak of laboratory-confirmed influenza for the 2005-2006 season was reported in a long-term care facility (LTCF) elsewhere in the country last week, and other common respiratory viruses are circulating as well. 
(see Canada's weekly FluWatch surveillance report at: <http://www.phac-aspc.gc.ca/fluwatch/index.html> )

In terms of the larger picture with respect to the respiratory [illness] season in Canada, we are likely to see many reports of respiratory outbreaks in nursing

homes and other institutions.  As is often the case, a proportion of these outbreaks may not have any identifiable etiologic agent.  Using increasingly sophisticated molecular testing techniques, laboratory scientists
are able to detect and identify previously unrecognizable pathogens, e.g. new coronaviruses and parvoviruses etc.  As a result, appropriate risk assessment is an important accompaniment to these reports, especially given the current wide media coverage of respiratory illnesses/outbreaks.

Toronto Public Health News Release:

http://wx.toronto.ca/inter/it/newsrel.nsf/bbe889573b1b4bc585256a9d00589271/63b4e996664a64d18525709200753944?OpenDocument

Susan Squires
Senior Epidemiologist
Immunization and Respiratory Infections Division (IRID)
Division d'immunisation et des infections respiratoires (DIIR)
Public Health Agency of Canada (PHAC)
Agence de santa publique du Canada (ASPC)
Building #6, AL 0602D, Tunney's Pasture
Ottawa, Ontario  Canada K1A 0L2
susan_squires1 TA phac-aspc.gc.ca

[ProMED-mail would like to thank Dr. Squires and the Public Health Agency of Canada for sending this update on the outbreak in Toronto.  The last paragraph is a very accurate and astute assessment of the situation most departments of health in the northern hemisphere are facing at this time of year and moving forward.

With the current concerns regarding when and where the next influenza pandemic will arise (and in the shadow of the SARS epidemic in 2002/2003), and on public health preparedness to both identify the onset of the pandemic early as well as to develop and implement control measures rapidly, there is a heightened focus of the media on coverage of outbreaks of febrile respiratory illness.  This current outbreak came to the attention of the media because it was "different" from the majority of febrile respiratory illness outbreaks in long-term care facilities, and in fact, the etiologic agent turned out to be _Legionella pneumophila_.

October 6, 2005
Statement by Dr. David McKeown, Medical Officer of Health
Announcement re: Respiratory Outbreak at Seven Oaks Nursing Home

Laboratory testing on autopsy specimens from three residents of Seven Oaks Home for the Aged were reported this afternoon as positive for Legionella pneumophila, the bacterium that causes Legionnaires Disease. This indicates that the cause of the current outbreak is likely Legionnaires Disease.

Legionnaires Disease is a form of pneumonia caused by bacteria formed naturally in the environment, usually in water. The bacteria grow best in warm water such as hot water tanks, large plumbing systems and air conditioning systems. People get Legionnaires Disease when they breath in air contaminated by droplets of water containing the bacteria. Legionnaires Disease is not transmitted from person to person. Most cases can be successfully treated with antibiotics, although older people with underlying health conditions are more likely to become seriously ill and die.

The Legionnaires Disease at Seven Oaks is confined to the nursing home. Because Legionnaires Disease is not transmitted from person to person, there is no risk to the general community.

There have been no new cases of infection for the past two days and it appears that transmission of the illness has subsided. There have been no further deaths.

Further testing will be carried out to confirm these findings. In the meantime Toronto Public Health is taking immediate action to protect the health of residents and staff.
 

Les autorités médicales de Toronto ont annoncé jeudi en fin de journée que la mystérieuse infection respiratoire ayant coûté la vie à 16 personnes âgées d'un foyer de Toronto était en fait la maladie du légionnaire ou légionellose.

"Les analyses de laboratoire effectuées à partir des autopsies de trois résidents de la maison "Seven Oaks Home for the Aged" sont positives en ce qui concerne la "legionella pneumophila", la bactérie qui cause la maladie du légionnaire", a déclaré le chef du service de santé de Toronto, le Dr David McKeown.

"Parce que la maladie du légionnaire ne se transmet pas de personne en personne, la population ne court aucun risque", a-t-il rassuré en précisant "qu'aucun nouveau cas d'infection au cours des trois derniers jours" n'a été répertorié et "qu'il n'y a eu aucun nouveau décès" depuis mercredi.

Trente-huit personnes étaient toujours hospitalisées jeudi, selon les responsables des services de la santé publique de Toronto.

Au total, 70 résidents, 13 employés et cinq visiteurs du "Seven Oaks Home for the Aged" ont été contaminés depuis la découverte du virus le 25 septembre.

"Ces résultats sont préliminaires. Nous allons continuons d'effectuer des recherches dans d'autres directions, mais nous pensons bien avoir affaire avec la maladie du légionnaire", a indiqué Donald Low, membre du laboratoire de santé publique de l'Ontario.

La "maladie du légionnaire" est une infection respiratoire provoquée par une bactérie hydrophile, qui se développe dans les systèmes de climatisation ou les douches mal désinfectées et touche particulièrement les personnes âgées. Ses symptômes ressemblent à ceux de la grippe: nausées, fièvre et perte d'appétit.

Le foyer "Seven Oaks", qui héberge habituellement 249 personnes, ne sera pas fermé, le système de climatisation a été débranché, de l'eau en bouteille de même que des antibiotiques préventifs ont été distribués aux résidents et au personnel de l'établissement, a précisé M. Low en ajoutant que la source de la bactérie n'est pas encore connue.

"Il n'y a pas et il n'y a jamais eu de menace pour le grand public à Toronto", a affirmé le maire de la ville, David Miller.

"Nous avons bénéficié des leçons tirées du passé", a-t-il poursuivi dans une référence à la crise du SRAS (syndrome respiratoire aigu sévère), qui avait fait 44 morts en 2003 dans le centre financier du Canada.

Vendredi, les autorités avaient fait part des quatre premiers décès dus au mystérieux virus respiratoire. Le nombre est ensuite passé à six dimanche, dix mardi et 16 mercredi.

Cette épidémie rappelait de pénibles souvenirs aux cinq millions d'habitants de la métropole économique du Canada, où la pneumonie atypique avait tué 44 personnes en 2003 et provoqué un grave ralentissement économique.

"Il ne s'agit pas du SRAS", avait cependant déclaré mercredi à la presse un haut responsable de la santé, le Dr David McKeown.

"L'épidémie étant confinée aux résidents, aux employés et aux personnes associées de près à cette institution, il n'y a donc pas de risque pour la santé publique", a-t-il insisté.

Les six personnes dont la mort a été annoncée mercredi luttaient déjà depuis quelques jours contre la bactérie et avaient également d'autres problèmes de santé, a précisé le Dr McKeown dans un communiqué. Ces personnes, trois hommes et trois femmes, étaient âgées entre 75 et 96 ans.

Les autorités avaient noté mercredi qu'aucun nouveau cas d'infection n'avait été signalé dans les 24 dernières heures.

Jeudi, trente-quatre personnes âgées, deux employés et deux visiteurs étaient toujours traités en isolement dans des hôpitaux de Toronto.

L'état de santé de la majorité de ces personnes s'améliore, mais se dégrade pour certains, avaient indiqué mercredi le Dr McKeown sans précision.

"Nous sommes maintenant confiants de pouvoir contrôler l'épidémie", avait-il déclaré, en soulignant que le nombre de nouveaux cas signalés n'avait cessé de diminuer depuis le 29 septembre, signe, selon lui, que la maladie régresse.

Dr. David McKeown, Toronto's Medical Officer of Health, reported late yesterday that testing by the Ontario Public Health Laboratory has identified two additional cases of Legionnaires' Disease in the vicinity of Seven Oaks Home for the Aged.

The two cases occurred during the height of the outbreak two weeks ago and both appear to have been exposed to the disease outside the Home. The individuals live or work in the immediate vicinity of Seven Oaks.

The investigation for a possible source of the illness continues. There is no evidence of any continuing risk of exposure to Legionnaires' Disease.

There have been no new cases with onset of illness since October 5 and no deaths since October 7.

    Dr. David Walker To Lead Review Of Outbreak

TORONTO, 17 October 2005 

An independent review of the legionnaires' disease outbreak in Toronto will be conducted by Dr. David Walker, Minister of
Health and Long-Term Care George Smitherman announced today.

"The legionnaires' disease outbreak was a tragedy that affected some of our most vulnerable citizens," Smitherman said. "I believe that Toronto Public
Health has done a good job in managing this outbreak. We now need to look closely at what worked and what improvements need to be made, and apply any
new lessons quickly."

    Dr. David Walker is currently the Dean, Faculty of Health Sciences at Queen's University. Dr. Walker chaired the expert panel on SARS and Infectious
Disease Control. This experience makes him a suitable candidate to evaluate actions taken during this outbreak, assess whether or not relevant lessons
learned from SARS were applied, and identify what can be learned from this experience in order to manage and respond to future outbreaks.
    
"I am pleased that someone of Dr. Walker's stature has agreed to take on this very important task," said Dr. Sheela Basrur, Ontario's Chief Medical
Officer of Health. "His experience with SARS will be invaluable."
   
 Dr. Walker's review will examine response times, processes, communication and co-ordination between the various organizations that were involved in the
management of the outbreak. These organizations include the Ministry of Health and Long-Term Care, the Ministry of Community Safety and Correctional
Services, Toronto Public Health, Toronto Emergency Medical Services, Seven Oaks Home for the Aged, and area hospitals.
    
Dr. Walker will begin his review immediately, with the final report presented to the public and the minister before the end of the year.

Cooling tower source of Legionnaires' outbreak

21 October 2005

Dr. David McKeown, Toronto's Medical Officer of Health, announced today that the source of the Legionnaires' Disease outbreak at Seven Oaks Home for the Aged has been identified as the 

air conditioning cooling tower on the roof of the Home.

Dr. David McKeown, Toronto's Medical Officer of Health, announced today that the source of the Legionnaires' Disease outbreak at Seven Oaks Home for the Aged has been identified as the 

air conditioning cooling tower on the roof of the Home.

"The source was confirmed earlier today by the Ontario Public Health Laboratory based on environmental samples collected by Toronto Public Health investigators," Dr. McKeown said. "

The cooling tower has been turned off since October 6, 2005, the day we learned that Legionnaires' was the cause of the outbreak. There is no risk to the public from this source since that time." 

Lab tests showed that the cooling tower contained the same legionella bacterium found in samples taken from residents. An air intake is located near the cooling tower. Droplets containing the

 bacterium were spread through the Home by the air handling system. The disease then affected a vulnerable population of elderly residents as well as staff and visitors.

A total of 20 residents have died and 127 people have become ill from Legionnaires' Disease

Source of legionnaires' disease outbreak found; 3 more deaths 

October 21 2005

Toronto: la climatisation à l'origine de la légionellose

21 October 2005

Une tour de conditionnement de l'air sur le toit du centre pour personnes âgées Seven Oaks, à Scarborough, est à l'origine de la flambée de la maladie du légionnaire, 

une infection respiratoire, à la fin septembre.

C'est ce qu'a affirmé le bureau de santé publique de Toronto, qui a fait part des résultats de son enquête, vendredi, après plus d'une semaine d'analyses