Killer bug spreads in Christchurch

Health authorities are urging Christchurch companies to check their air-conditioning units as the country's worst outbreak of legionnaires' disease claims more victims.

Homeowners are also being encouraged to check their home hot-water systems to ensure they are heating water to a sufficient temperature to kill any bugs.

Two more cases of legionnaires' disease were notified yesterday, bringing the total number of people infected in Canterbury so far this year to 16, including 13 since June.

Two of the 16 – both middle-aged men – have died from the lung disease. The latest cases to be notified are of a man aged in his 20s, and a woman in her 60s. The woman has been hospitalised.

Canterbury Medical Officer of Health Dr Mel Brieseman told The Press yesterday that the woman's condition was satisfactory, "as far as I'm aware".

As he did not know her name, the hospital could not release any information about her condition.

Health authorities have been unable to pinpoint the source of the disease, and are now asking building owners for help.

Legionnaires' disease is caused by the bacterium Legionella, which is found in soil and water.

It grows in air-conditioning systems, spa pools, fountains, or in potting mix or compost. It is not passed from person to person.

Past outbreaks have been linked to poorly maintained air-conditioning cooling towers.