Division Laboratory criteria

Laboratory criteria for case confirmation

At least one of the following three:

• Isolation of Legionella spp. from respiratory secretions or any normally sterile site

• Detection of Legionella pneumophila antigen in urine

• Legionella pneumophila serogroup 1 specific antibody response

Laboratory criteria for a probable case

At least one of the following four:

• Detection of Legionella pneumophila antigen in respiratory secretions or lung tissue e.g. by DFA staining using monoclonal-antibody derived reagents

• Detection of Legionella spp. nucleic acid in a clinical specimen

• Legionella pneumophila non-serogroup 1 or other Legionella spp. specific antibody response

• L. pneumophila serogroup 1, other serogroups or other Legionella species: single high titre in specific serum antibody