A major outbreak of legionnaires' disease in Auckland has claimed one life and the number of reported cases has risen to 11.

The Auckland Regional Public Health Service yesterday said a woman died this week. She had other pre-diagnosed health issues.

The service would not say where the woman was from in Auckland to avoid sparking fears about the source of the disease, but is working closely with her family to determine the source of exposure over the past two weeks.

The Auckland region has been hit by a sudden increase in reported cases of the potentially fatal lung infection, prompting the health service to ask for urgent chemical treatment in all buildings with air-conditioning that relies on water cooling towers.


On Tuesday the service said it had been notified of nine cases of legionnaires' disease in the past six weeks. By yesterday, the figure rose to 11.

The Auckland Council and other agencies are working together to contact building owners that have cooling towers or use an industrial process that recirculates water and generates aerosols, so that they are aware of the need to shock-dose their cooling systems.

The council's building control manager, Ian McCormick, said the owners of about 350 buildings with mechanical ventilation systems that had cooling towers had been contacted to arrange immediate shock-dosing of these systems.

The council was also tracking down buildings with cooling towers that were not registered.

"The problem with cooling towers is because they are open to the atmosphere, there is an ability to contaminate other cooling towers in the vicinity," Mr McCormick said.

Legionnaires' disease, a form of pneumonia, can be caught from the contaminated water cooling towers of large air-conditioning systems, domestic shower heads, spa pools, water blasting and soil, compost and potting mix. The risk from large air-conditioning systems is to the building's occupants and to people on the streets exposed to contaminated, wind-borne water droplets.

* A form of pneumonia caused by inhaling water or soil contaminated with legionella bacteria.

* Symptoms: Muscle aches, headache, tiredness, loss of appetite and coughing. Followed by high fever, chills and occasionally diarrhoea.


* Treatment: Antibiotics.