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

• Significant rise in specific antibody level to Legionella pneumophila serogroup 1 in paired serum samples

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 respiratory secretions, lung tissue or any normally sterile site

• Significant rise in specific antibody level to Legionella pneumophila other than serogroup 1 or other Legionella spp. in paired serum samples

• Single high level of specific antibody to Legionella pneumophila serogroup 1 in serum