Legionella information

Legionella Reference Laboratory

Legionellosis is a sometimes fatal respiratory disease that follows infection with Legionella, a bacterium widely distributed in soil and water sources throughout New Zealand.

Legionellosis is primarily contracted after exposure to an environmental source contaminated with the bacterium. It is a notifiable disease in New Zealand, with more than 100 cases reported and confirmed each year. Contaminated water systems have frequently been the source for outbreaks of disease caused by Legionella. 

There are more than 50 species of Legionella, of which 20 have been associated with human infection. The main Legionella species causing disease in New Zealand are Legionella pneumophila and Legionella longbeachae. Epidemiological evidence has shown that since 1979 contaminated water has been the predominant exposure source for L. pneumophila infections. Although L. longbeachae is commonly associated with compost use, infections it causes have also been traced to contaminated water systems.

Our laboratory holds IANZ accreditation for both ISO 17025 and ISO 15189 for Legionella testing and typing.

At ESR, we test for Legionella in water and biofilm samples from:

  • cooling towers

  • drinking-water supplies

  • groundwater

  • ice machines

  • industrial machinery

  • rainwater storage tanks

  • recreational water

  • spa-pool water

  • spray equipment

  • spring water

  • vehicle wash equipment

  • water fountains

  • water reticulation systems

We can advise on:

  • risk assessment and management plans

  • the mitigation and control of Legionella bacteria in reticulated piping systems

  • the validation of testing protocols

  • quantitative assessments of remediation action after contamination

How to collect environmental samples for Legionella testing

For full details about collecting environmental samples to be examined for the presence of Legionella bacteria, please read the Environmental Sampling for Legionella Bacteria guidelines or contact lab staff via KSC.Legionella@esr.cri.nz or phone 04 914 0755.