Product Information

Legionella Isolation Scheme

General information about the scheme

The distributions are prepared by Health Protection Agency staff with many years' experience of the detection and isolation of Legionella species and are designed to provide information on the reliability of both the isolation media and the concentration and selection procedure.

Samples

The individual samples may contain one or more species of Legionella that have never been grown on artificial media along with a supporting natural aquatic flora, aquatic bacteria but no legionellae, a species of Legionella by itself or be sterile. The number of legionellae in the samples will be varied to simulate the full range of concentrations encountered in nature. The 'concentrates' are dispatched in LENTICULE disc format in plastic containers .

Schedule

Typically, there are four distributions per year, each containing three samples of simulated concentrates from water. After examination of the samples on the prescribed date, the results are returned by fax, post or electronic mail. For most distributions three weeks are allowed between the prescribed date of analysis and the return of the reports. After the closing date for receipt of results a preliminary report is distributed to all participants indicating the intended result.

Requirements

On a specified month and using a set protocol, participants are required to transfer the LENTICULE disc to 1 Litre of diluent (use either Page's so ;ution or 1:40 Ringers solution) by inverting the container over the diluent . The diluted concentrate is the simulated water sample which each participant must process according to their usual methods.

Although the numbers of organisms in the samples are sufficiently stable to enable them to be distributed by post they must be examined on the prescribed date to ensure that reliable comparable results are obtained.

Performance Assessment

Following analysis of the results, a comprehensive report is issued, including anonymised charts which illustrate the compiled results of all laboratories. The individual participating laboratory's results are marked, and these are supported by explanatory comments. An annual performance assessment will be provided, and the organisers are always available to assist with advice or comments on any problems which participants may experience during their routine procedures.

Safety

Legionella species are microbiological pathogens of hazard Group 2 as defined by the Advisory Committee on Dangerous Pathogens. Although Hazard Group 2 organisms can, in general, be handled on the open bench, patients become infected with Legionella species by inhaling an aerosol generated from water containing the organism. Participants must assure themselves that their laboratory facilities and expertise are adequate to ensure the safe handling of these organisms.

Research and Development

Research into technical aspects of the Scheme and development of the analysis and presentation of results is a continuing process.

External Quality Assessment

Quality Assessment is an essential element of good laboratory practice; a scheme that is organised externally enables laboratories to assess their performance against that of other participants. Health Protection Agency EQA Schemes provide stable samples of appropriate organisms within agreed schedules and with comprehensive, confidential follow-up. Participants are invited to regular user group meetings. Each Scheme has been developed with Health Protection Agency microbiological expertise. As well as The Legionella Isolation Scheme, the Health Protection Agency runs four other Water EQA Schemes, and five Food EQA Schemes.

Registration

To register for The Legionella Isolation Scheme, please complete the registration form  , first reading the terms and conditions.

Last reviewed: 20 May 2009