Public health officials in Westminster launched a nationwide alert after it was learnt that the three victims worked in, or had visited, the Piccadilly- Leicester Square area of London in the 10 days before the onset of illness. Five people died in 1989 after an outbreak linked to water cooling towers on office buildings in Piccadilly.
The latest outbreak poses a major problem for Westminster Council, being linked with one of the most popular tourist sites as the holiday season begins. More than 4 million people visit Trafalgar Square each year. Doctors and environmental health officers are trying to identify the source of the infection.
A spokesman for the Department of National Heritage said the fountains had been emptied as a 'precautionary measure' at the request of the council. The London Tourist Board said that it was 'more important to be responsible and turn the fountains off than to risk people's health'.
All cooling towers in the area have been shut down for cleansing and disinfection, but no traces of Legionella bacteria have been found in any tower so far.
Legionella, the bacterium which causes the pneumonia- like illness, breeds in dirty, warm pools of stagnant water, and people are exposed to it through breathing in contaminated water vapour.
The symptoms inlude a flu- like malaise, aches and headaches, followed by chest pains, a dry cough, high fever and confusion. The incubation period is between two and ten days.
It is known that the victims had visited the area between 4 and 13 April. A man from north London was admitted to St Thomas's Hospital on 15 April and died three days later. Two other people treated in different hospitals have now recovered.
Doctors were unable to isolate bacteria from all three patients - if the strains were related it would have provided a clue to the origin, and evidence that the outbreak was linked.
The situation was further complicated as one of those infected had just returned from the Canary Islands. Most cases of the disease in Britain are contracted abroad.
Specialists in communicable diseases have been alerted and are checking cases of pneumonia to see if Legionella is responsible, and if the patients had been in the central London area.
Most outbreaks in this country are linked with hot water systems, but cooling towers in air conditioning systems are also a source. In 1988 three people died in an outbreak at Broadcasting House in London.
After the 1989 outbreak, environmental health officers condemned the 'appalling' state of cooling towers in the West End. Research in Glasgow has shown that people living within a third of a mile of a cooling tower were three times more likely to catch the disease than people living double the distance away.Reuse content