Clinical and epidemiological characteristics of Legionnaires' disease in Southern Sweden, a population-based study
(2025) In Infectious Diseases p.1-12- Abstract
BACKGROUND: The study aimed to describe all diagnosed cases of Legionnaire's disease (LD) in south Sweden, regarding incidence, patient characteristics, diagnostics, outcomes, and infection control investigations.
METHODS: This population-based retrospective study was conducted in Skåne, on patients with LD between 2011-2021. Inclusion criteria were positive polymerase chain reaction (PCR) for
L. pneumophila/
Legionella spp. or a positive urinary antigen test (UAT), combined with a clinical presentation consistent with
Legionella infection and radiological evidence of pulmonary infiltrates.
RESULTS: A total of 280 patients met the inclusion criteria, with a mean incidence of 2.00 per 100,000 person-years... (More)
BACKGROUND: The study aimed to describe all diagnosed cases of Legionnaire's disease (LD) in south Sweden, regarding incidence, patient characteristics, diagnostics, outcomes, and infection control investigations.
METHODS: This population-based retrospective study was conducted in Skåne, on patients with LD between 2011-2021. Inclusion criteria were positive polymerase chain reaction (PCR) for
L. pneumophila/
Legionella spp. or a positive urinary antigen test (UAT), combined with a clinical presentation consistent with
Legionella infection and radiological evidence of pulmonary infiltrates.
RESULTS: A total of 280 patients met the inclusion criteria, with a mean incidence of 2.00 per 100,000 person-years (95% CI: 1.23-2.78). Empiric treatment covering
Legionella was administered in 15% of cases. Mortality rates were 13%, 15% and 23% at 30-, 90- and 365 days, respectively. UAT was performed in 88% of patients, with a 66% positivity rate. Lower respiratory tract PCR was performed in 76% of patients with a 90% positivity rate. Bacterial culture was positive in 43% of cases. Out of these,
L. pneumophila serogroup 1 was most common (58%), though a significant proportion were serogroups 2-14 (30%), which are not generally detected by UAT. Genetic matches between environmental and patient strains were established in 5% of cases.
CONCLUSION: Legionnaires' disease in Skåne is an uncommon but clinically significant condition. Few patients received appropriate empiric antibiotic treatment. Reliance on UAT alone is insufficient for establishing diagnosis, and species-specific PCR, particularly from lower respiratory samples, enhances detection. Environmental investigations frequently identified
(Less)
Legionella in suspected settings; however, a definitive source of infection was rarely established.
- author
- Wikén, Christian ; Eliasson, Jenny ; Alanko Blomé, Marianne LU ; Fält, Rosmarie ; Resman, Fredrik LU ; Ljungquist, Oskar LU and Wasserstrom, Lisa LU
- organization
- publishing date
- 2025-04-07
- type
- Contribution to journal
- publication status
- epub
- subject
- in
- Infectious Diseases
- pages
- 1 - 12
- publisher
- Taylor & Francis
- external identifiers
-
- scopus:105002616471
- pmid:40192664
- ISSN
- 2374-4235
- DOI
- 10.1080/23744235.2025.2476532
- language
- English
- LU publication?
- yes
- id
- a09dd2be-1f78-4e9e-ac84-dce5ead95ce2
- date added to LUP
- 2025-04-18 14:09:50
- date last changed
- 2025-04-22 07:51:40
@article{a09dd2be-1f78-4e9e-ac84-dce5ead95ce2,
abstract = {{<p>BACKGROUND: The study aimed to describe all diagnosed cases of Legionnaire's disease (LD) in south Sweden, regarding incidence, patient characteristics, diagnostics, outcomes, and infection control investigations.</p><p>METHODS: This population-based retrospective study was conducted in Skåne, on patients with LD between 2011-2021. Inclusion criteria were positive polymerase chain reaction (PCR) for<br>
L. pneumophila/<br>
Legionella spp. or a positive urinary antigen test (UAT), combined with a clinical presentation consistent with<br>
Legionella infection and radiological evidence of pulmonary infiltrates.<br>
</p><p>RESULTS: A total of 280 patients met the inclusion criteria, with a mean incidence of 2.00 per 100,000 person-years (95% CI: 1.23-2.78). Empiric treatment covering <br>
Legionella was administered in 15% of cases. Mortality rates were 13%, 15% and 23% at 30-, 90- and 365 days, respectively. UAT was performed in 88% of patients, with a 66% positivity rate. Lower respiratory tract PCR was performed in 76% of patients with a 90% positivity rate. Bacterial culture was positive in 43% of cases. Out of these,<br>
L. pneumophila serogroup 1 was most common (58%), though a significant proportion were serogroups 2-14 (30%), which are not generally detected by UAT. Genetic matches between environmental and patient strains were established in 5% of cases.<br>
</p><p>CONCLUSION: Legionnaires' disease in Skåne is an uncommon but clinically significant condition. Few patients received appropriate empiric antibiotic treatment. Reliance on UAT alone is insufficient for establishing diagnosis, and species-specific PCR, particularly from lower respiratory samples, enhances detection. Environmental investigations frequently identified<br>
Legionella in suspected settings; however, a definitive source of infection was rarely established.<br>
</p>}},
author = {{Wikén, Christian and Eliasson, Jenny and Alanko Blomé, Marianne and Fält, Rosmarie and Resman, Fredrik and Ljungquist, Oskar and Wasserstrom, Lisa}},
issn = {{2374-4235}},
language = {{eng}},
month = {{04}},
pages = {{1--12}},
publisher = {{Taylor & Francis}},
series = {{Infectious Diseases}},
title = {{Clinical and epidemiological characteristics of Legionnaires' disease in Southern Sweden, a population-based study}},
url = {{http://dx.doi.org/10.1080/23744235.2025.2476532}},
doi = {{10.1080/23744235.2025.2476532}},
year = {{2025}},
}