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Environmental Legionella Isolation Techniques Evaluation Program

New! ELITE Move Offers Opportunities for Expansion, Improvement

Part of CDC’s Environmental Legionella Isolation Techniques Evaluation (ELITE) Program is moving to Wisconsin. In November 2016, the Wisconsin State Laboratory of Hygiene began managing the production and distribution of testing samples, as well as analysis of lab results. CDC’s continued role will be to oversee the ELITE Program as a whole, provide customer support to members, and host the public, online members list.

Learn more…


Although Legionella lives in a wide variety of freshwater habitats, it can be difficult to isolate. CDC’s Environmental Legionella Isolation Techniques Evaluation (ELITE) Program was created as a way for laboratories to test their Legionella isolation techniques against standardized samples.

ELITE Application Website

Elite program screenshot

Visit the ELITE application website to view a list of laboratories that have met proficiency standards to be an ELITE member and to enroll as a new member in the program. Current members can also enter test results and receive their certificates through the website. A few areas of the ELITE application website are password protected for members only.

Frequently Asked Questions

For the General Public and Public Health Agencies

Elite program logo.

Q: Why does CDC offer the ELITE Program?

A: The ELITE Program certifies labs in the isolation of Legionella from water samples. Labs that are proficient in Legionella isolation are listed on the ELITE Members List as a service for the general public. Labs that perform adequately receive a Certificate of Proficiency that indicates that the lab’s procedures are consistent with federal recommendations and that they meet or exceed typical industry standards for recovery of Legionella.

Q: Who is being certified?

A: Any lab that cultures environmental samples for Legionella can participate in the ELITE Program. For labs located in the United States or U.S. territories, the program is voluntary and free of charge. For labs located outside the United States, shipping fees are required. Member labs may be commercial or affiliated with a university or state health department.

Q: How are labs certified?

A: Participating labs receive two panels of unknown samples each year. Labs that correctly identify which samples contain Legionella in both panels immediately earn a Certificate of Proficiency and are listed as ELITE Members on the website and map. ELITE members must recertify annually to remain on the list.

Q: What types of lab testing are certified?

A: The ELITE Program certifies labs that are able to find Legionella in a water sample by culture. Appropriate culture protocols include water sample treatment, isolate identification, and characterization. Molecular (e.g., polymerase chain reaction or PCR), serological (e.g., direct fluorescent antibody or DFA), or rapid analytical tests (e.g., dipstick) are not evaluated. The ELITE Program does not certify performance of these other technologies because methods other than culture are suitable for supplemental testing, but are not discriminating enough to be applied as a primary test for environmental samples. The Certificate of Proficiency does not guarantee that a lab will be able to isolate legionellae from every sample they are presented because the limit of detection may be affected by sample quality. The ELITE Program does not certify sampling methodology.

Q: Are all participants on the ELITE Members List?

A: No. Only participants who have demonstrated proficiency in recovering Legionella from a water sample are listed as ELITE members.

Q: What does it mean if the lab I am using is not on the ELITE Members List?

A: Participation in the ELITE Program is voluntary so not all qualified labs will be listed as ELITE members. Additionally, it takes a minimum of 3 months for a new lab to become certified. Thus, CDC cannot comment on the proficiency of individual labs that are not listed on the ELITE Members List.

Q: Can ELITE members provide Legionella remediation services?

A: Possibly, but this is beyond the scope of ELITE certification. The ELITE Program certifies labs in their ability to isolate Legionella from water samples (i.e., to determine if Legionella is present); it does not certify their ability to eliminate Legionella from water systems.

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