KEY POINTS:
Positive results for potentially deadly legionella bacteria have been found in routine monthly testing of cooling towers in Auckland's central business district.
But the Auckland Regional Public Health Service (ARPHS) said today there was a low risk to people's health.
ARPHS medical officer of health Kathy Pikholz said
appropriate corrective action had been taken at the affected cooling towers with them being thoroughly cleaned, disinfected with chlorine, and re-tested.
Three people died from legionella in Christchurch during the winter of 2005.
The three deaths were part of an outbreak of 19 cases clustered in the southwest of the city.
Dr Pikholz said ARPHS was working closely with the Auckland City Council and Department of Labour to determine the extent of the problem, and whether other cooling towers in the CBD were affected.
"The risk that this could cause illness is small, and people should go about their usual business in the CBD," she said.
ARPHS commended those building owners who had reported their results and taken prompt corrective action.
But Dr Pikholz warned that people should seek medical attention if they developed symptoms suggestive of legionellosis.
Symptoms include muscle aches, headache, tiredness, loss of appetite and coughing, followed by high fever, chills and occasionally diarrhoea.
In people with the milder form of legionellosis, called pontiac fever, there would be the flu-like symptoms but no pneumonia.
In the more severe form of legionellosis, called legionnaire's disease, pneumonia would be present on clinical examination and on chest x-rays.
Legionellosis is not caught by drinking contaminated water, nor is it passed from one person to another. Generally it is caught by inhaling mists or spray from water that contains legionella bacteria.
Legionella bacteria are commonly found in the environment; however, only a small percentage of people exposed to the bacteria get sick.
Dr Pikholz said children or those in good health rarely got the illness, and up to 20 per cent of healthy adults had antibodies showing previous exposure to legionella bacteria.
But some adults with medical conditions may be vulnerable as well as older people, heavy smokers, people with chronic lung disease or conditions that lower immunity (such as diabetes, cancer or kidney failure) or were on immune suppressing drugs (such as high doses of steroids).
Auckland City Council acting chief executive John Duthie said the building owner where the legionella had first been discovered had moved quickly to have the cooling towers cleaned up.
"In the last 24 hours we have been advised that another building has tested with high levels of the bacteria," Mr Duthie said.
"In both cases, we are advised, the buildings' owners have informed their tenants."
Mr Duthie said that the city council was advising all CBD building owners to take the precautionary step of testing for legionella.
"There are no reports of anyone having fallen ill with the diseases caused by legionella bacteria, but we ask that this testing be done before the next due date.
"Single isolated cases are ordinarily resolved with the assistance of the affected building owner," he said.
"The reason for this public announcement is due to the second instance of this bacteria. The two buildings with high levels may be a coincidence, but the council and the ARPHS need the data to make a judgment as to whether or not there is cause for greater concern."
- NZPA