Development of a TLDA card for Legionella diagnostics and typing
Research type
Research Study
Full title
Development of a TLDA card for the simultaneous diagnosis and subtyping of Legionella
IRAS ID
214744
Contact name
Vicki Chalker
Contact email
Sponsor organisation
UKHSA
Duration of Study in the UK
1 years, 4 months, 31 days
Research summary
Research Summary
Legionnaires’ disease is a severe pneumonia and a significant public health concern. Detection of infection and
source identification requires analysis of patient and environmental samples. Clinical samples and environmental
isolates are referred to the Public Health England Respiratory and Vaccine Preventable Bacteria Reference Unit
(RVPBRU) where several diagnostic tests are used to confirm infection and link patients to environmental sources.
Techniques are time consuming, largely limited to Legionella pneumophila and expensive. Reliance on some current
assays for primary testing may not detect infection with unusual Legionella types and these infections may go undiagnosed.
The majority of detected human infections and point source outbreaks are caused by a limited number of
specific types of Legionella pneumophila serogroup 1 called sequence types. The researchers in this study will use
unique data on Legionella genetic content to design novel diagnostic tests that can differentiate all clinically relevant
Legionella and the most common Legionella pneumophila serogroup 1 sequence types. These tests will be
combined into a single format called a Taqman Array Card. These can produce results in approximately 90 minutes
compared to several days by traditional methods. The new Taqman array card will be evaluated on both primary
clinical samples (obtained from NHS laboratories for diagnostic purposes), stored Legionella grown from historical
patient samples and environmental water samples. Sensitivity and specificity of the new assay will be determined and
compared to existing traditional techniques. A beta trial involving European Reference lab partners will follow.
Following successful validation, implementation of such an assay will bring several benefits, significantly reducing
time to results, improving PHE response to incidents providing a diagnostic service for all Legionella infections (not
just Legionella pneumophila) and substantially reducing overall testing costs.Summary of Results
• This study was initiated to develop a multiplex PCR for the detection and typing of legionella.
• The test was developed to detect legionella and other water pathogens, subtypes of legionella. Validation was partially completed.
• Insufficient staffing and funding prevented completion of the validation of the study.
• The main investigator left the organisation in June 2022
• No pharmaceutical formulation was used in the study.REC name
Wales REC 4
REC reference
16/WA/0329
Date of REC Opinion
28 Nov 2016
REC opinion
Further Information Favourable Opinion