Legionella Reference Laboratory

The Legionella Reference Laboratory at Statens Serum Institut receives clinical samples and Legionella isolates from the whole country for identification, serogroup examination and DNA typing

For source investigation and evaluation, water samples or environmental isolates are received for culture and identification and typing.

The laboratory participates in cooperation with the diagnostic laboratories at Statens Serum Institut (SSI) and local Clinical Microbiology Laboratories, together with the Department of Infectious Disease Epidemiology, SSI and the Danish Patient Safety Authority in the nationwide surveillance of Legionnaires’ disease.

Advice is provided concerning treatment, diagnosis, prevention, testing of water samples, risk assessment and source investigation.

  • The reference function works closely together with the diagnostic laboratories at SSI concerning the diagnosis of legionella infections by culture, PCR (Polymerase Chain Reaction), urinary antigen tests and serology and detection of Legionella in environmental samples (mainly water) by culture and PCR
  • The reference function, together with the Department of Infectious Disease Epidemiology is the national ECDC nominated contact point for Legionnaires’ disease and participates actively in the European Legionnaires' Disease Surveillance Network (ELDSNet) which mainly monitors travel associated cases 
  • The Laboratory managers are members of the ESCMID Study Group for Legionella Infections (ESGLI)


  • Travel associated cases are reported regularly to the ECDC (ELDSNet)
  • All cases with epidemiological and microbiological data are annually reported to ELDSNet
  • Annual reports on SSI.dk and in EPI-NEWS 
  • Results of source investigations are reported to the Danish Patient Safety Authority

Reference – laboratory functions 

  • Isolation by culture and identification of Legionella from patient samples
  • Species identification of Legionella isolates
  • Serogroup identification of Legionella pneumophila isolates 
  • Subgroup identification of Legionella pneumophila serogroup 1 isolates
  • DNA typing by whole genome sequencing and by sequence based typing (SBT) of Legionella pneumophila isolates

Related – laboratory functions

  • Quantification and identification of Legionella in environmental samples by culture and qPCR