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International Journal of Hygiene and... Jun 2018Most Legionnaires' disease in the US and abroad is community-acquired and believed to be sporadic, or non-outbreak associated. Most patients are exposed to numerous... (Review)
Review
BACKGROUND
Most Legionnaires' disease in the US and abroad is community-acquired and believed to be sporadic, or non-outbreak associated. Most patients are exposed to numerous water sources, thus making it difficult to focus environmental investigations. Identifying known sources of sporadic community-acquired Legionnaires' disease will inform future sporadic Legionnaires' disease investigations as well as highlight directions for research. The objective is to summarize and rank sporadic Legionnaires' disease sources based on the level of linkage between the environmental source and cases.
METHODS
A PubMed search was conducted using the search terms legion* and (origins or source or transmission) and (sporadic or community-acquired). Studies of nosocomial and/or outbreak-associated disease were excluded from this review. Definite, probable, possible and suspect ranks were assigned to sources based on evidence of linkage to sporadic Legionnaires' disease.
RESULTS
The search yielded 196 articles and 47 articles were included in the final review after application of exclusion criteria. A total of 28 sources were identified. Of these, eight were assigned definite rank including residential potable water and car air-conditioner water leakage. Probable rank was assigned to five sources including solar-heated potable water and soil. Possible rank was assigned to nine sources including residential potable water and cooling towers. Suspect rank was assigned to 20 sources including large building water systems and cooling towers.
CONCLUSION
Residential potable water, large building water systems and car travel appear to contribute to a substantial proportion of sporadic Legionnaires' disease. Cooling towers are also a potentially significant source; however, definitive linkage to sporadic cases proves difficult. The sources of sporadic Legionnaires' disease cannot be definitively identified for most cases.
Topics: Air Conditioning; Community-Acquired Infections; Drinking Water; Environmental Pollutants; Humans; Legionella; Legionnaires' Disease; Soil Microbiology; Water Microbiology
PubMed: 29729999
DOI: 10.1016/j.ijheh.2018.04.013 -
Infectious Disease Clinics of North... Mar 2017Legionnaire's disease is a nonzoonotic atypical pneumonia caused by Legionella sp that occurs sporadically or in outbreaks. Legionnaire's disease pneumonia is... (Review)
Review
Legionnaire's disease is a nonzoonotic atypical pneumonia caused by Legionella sp that occurs sporadically or in outbreaks. Legionnaire's disease pneumonia is accompanied by several extrapulmonary clinical and laboratory findings. Rather than testing all pneumonias for Legionnaire's disease, the clinical challenge is to recognize the diagnostic significance of Legionnaire's disease's. The pretest probability of Legionnaire's disease is increased if several characteristic extrapulmonary findings are present. Similarly, if certain key findings are absent, Legionnaire's disease may be eliminated from further diagnostic consideration. If characteristic clinical findings are present, then specific tests should be ordered to confirm or rule out Legionnaire's disease.
Topics: Blood Sedimentation; C-Reactive Protein; Disease Outbreaks; Ferritins; Humans; Hyponatremia; Hypophosphatemia; Legionnaires' Disease; Pneumonia, Bacterial
PubMed: 28159178
DOI: 10.1016/j.idc.2016.10.007 -
The Lancet. Infectious Diseases Oct 2014Legionnaires' disease is an important cause of community-acquired and hospital-acquired pneumonia. Although uncommon, Legionnaires' disease continues to cause disease... (Review)
Review
Legionnaires' disease is an important cause of community-acquired and hospital-acquired pneumonia. Although uncommon, Legionnaires' disease continues to cause disease outbreaks of public health significance. The disease is caused by any species of the Gram-negative aerobic bacteria belonging to the genus Legionella; Legionella pneumophila serogroup 1 is the causative agent of most cases in Europe. In this Review we outline the global epidemiology of Legionnaires' disease, summarise its diagnosis and management, and identify research gaps and priorities. Early clinical diagnosis and prompt initiation of appropriate antibiotics for Legionella spp in all patients with community-acquired or hospital-acquired pneumonias is a crucial measure for management of the disease. Progress in typing and sequencing technologies might additionally contribute to understanding the distribution and natural history of Legionnaires' disease, and inform outbreak investigations. Control of Legionnaires' disease outbreaks relies on rapid ascertainment of descriptive epidemiological data, combined with microbiological information to identify the source and implement control measures. Further research is required to define the actual burden of disease, factors that influence susceptibility, key sources of infection, and differences in virulence between strains of Legionella species. Other requirements are improved, specific, sensitive, and rapid diagnostic tests to accurately inform management of Legionnaires' disease, and controlled clinical trials to ascertain the optimum antibiotics for treatment.
Topics: Bacterial Typing Techniques; Disease Outbreaks; Global Health; Humans; Legionella pneumophila; Legionnaires' Disease; Virulence
PubMed: 24970283
DOI: 10.1016/S1473-3099(14)70713-3 -
International Journal of Medical... Jan 2018Legionella pneumophila is a facultative intracellular bacterium which can cause a severe pneumonia called Legionnaires' disease after inhalation of contaminated water... (Review)
Review
Legionella pneumophila is a facultative intracellular bacterium which can cause a severe pneumonia called Legionnaires' disease after inhalation of contaminated water droplets and replication in alveolar macrophages. The innate immune system is generally able to sense and -in most cases- control L. pneumophila infection. Comorbidities and genetic risk factors, however, can compromise the immune system and high infection doses might overwhelm its capacity, thereby enabling L. pneumophila to grow and disseminate inside the lung. The innate immune system mediates sensing of L. pneumophila by employing e.g. NOD-like receptors (NLRs), Toll-like receptors (TLRs), as well as the cGAS/STING pathway to stimulate death of infected macrophages as well as production of proinflammatory cytokines and interferons (IFNs). Control of pulmonary L. pneumophila infection is largely mediated by inflammasome-, TNFα- and IFN-dependent macrophage-intrinsic resistance mechanisms. This article summarizes the current knowledge of innate immune responses to L. pneumophila infection in general, and of macrophage-intrinsic defense mechanisms in particular.
Topics: Cytokines; Host-Pathogen Interactions; Humans; Immunity, Innate; Inflammasomes; Legionella pneumophila; Legionnaires' Disease; Macrophages, Alveolar; Signal Transduction
PubMed: 29097162
DOI: 10.1016/j.ijmm.2017.10.004 -
Environmental Science & Technology Apr 2015Legionella bacteria are ubiquitous in natural matrices and man-made systems. However, it is not always clear if these reservoirs can act as source of infection resulting... (Review)
Review
Legionella bacteria are ubiquitous in natural matrices and man-made systems. However, it is not always clear if these reservoirs can act as source of infection resulting in cases of Legionnaires' disease. This review provides an overview of reservoirs of Legionella reported in the literature, other than drinking water distribution systems. Levels of evidence were developed to discriminate between potential and confirmed sources of Legionella. A total of 17 systems and matrices could be classified as confirmed sources of Legionella. Many other man-made systems or natural matrices were not classified as a confirmed source, since either no patients were linked to these reservoirs or the supporting evidence was weak. However, these systems or matrices could play an important role in the transmission of infectious Legionella bacteria; they might not yet be considered in source investigations, resulting in an underestimation of their importance. To optimize source investigations it is important to have knowledge about all the (potential) sources of Legionella. Further research is needed to unravel what the contribution is of each confirmed source, and possibly also potential sources, to the LD disease burden.
Topics: Disease Reservoirs; Humans; Legionella; Legionellosis; Legionnaires' Disease; Water Microbiology
PubMed: 25774976
DOI: 10.1021/acs.est.5b00142 -
Emerging Infectious Diseases Oct 2020Healthcare-associated Legionnaires' disease (HCA LD) can cause nosocomial outbreaks with high death rates. We compared community-acquired LD cases with HCA LD cases in...
Healthcare-associated Legionnaires' disease (HCA LD) can cause nosocomial outbreaks with high death rates. We compared community-acquired LD cases with HCA LD cases in Europe during 2008-2017 using data from The European Surveillance System. A total of 29 countries reported 40,411 community-acquired and 4,315 HCA LD cases. Of the HCA LD cases, 2,937 (68.1%) were hospital-acquired and 1,378 (31.9%) were linked to other healthcare facilities. The odds of having HCA LD were higher for women, children and persons <20 years of age, and persons >60 years of age. Out of the cases caused by Legionella pneumophila with a known serotype, community-acquired LD was more likely to be caused by L. pneumophila serogroup 1 (92.3%) than was HCA LD (85.1%). HCA LD patients were more likely to die. HCA LD is associated with specific patient demographics, causative strains, and outcomes. Healthcare facilities should consider these characteristics when designing HCA LD prevention strategies.
Topics: Child; Delivery of Health Care; Disease Outbreaks; Europe; Female; Humans; Legionella pneumophila; Legionnaires' Disease
PubMed: 32946366
DOI: 10.3201/eid2610.181889 -
American Journal of Infection Control Nov 2023Legionella pneumophila is a common cause of community-acquired pneumonia. We aimed to determine the pooled rates of L pneumophila contamination in the water environment... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Legionella pneumophila is a common cause of community-acquired pneumonia. We aimed to determine the pooled rates of L pneumophila contamination in the water environment of the hospital.
METHODS
We searched PubMed, Embase, Web of Science, Chinese National Knowledge Infrastructure, WangFang and Science Direct, The Cochrane Library, and Science Finder, for relevant studies published until December 2022. Stata 16.0 software was used to determine pooled contamination rates, publication bias, and subgroup analysis.
RESULTS
Forty-eight eligible articles with a total of 23,640 samples of water were evaluated, and the prevalence of L pneumophila was 41.6%. The results of the subgroup analysis showed that the pollution rate of L pneumophila in hot water (47.6%) was higher than that in other water bodies. The rates of L pneumophila contamination were higher in developed countries (45.2%), culture methods (42.3%), published between 1985 and 2015 (42.9%), and studies with a sample size of less than 100 (53.0%).
CONCLUSIONS
L pneumophila contamination in medical institutions is still very serious and should be paid attention to, especially in developed countries and hot water tanks.
Topics: Legionella pneumophila; Hospitals; Water Microbiology; Humans; Legionnaires' Disease; Prevalence
PubMed: 37054892
DOI: 10.1016/j.ajic.2023.04.002 -
Acta Bio-medica : Atenei Parmensis Aug 2023Legionnaires' disease is a severe form of pneumonia caused by the inhalation or aspiration of water droplets contaminated with Legionella pneumophila and other...
BACKGROUND AND AIM
Legionnaires' disease is a severe form of pneumonia caused by the inhalation or aspiration of water droplets contaminated with Legionella pneumophila and other Legionella species. These bacteria are commonly found in natural habitats and man-made water systems. Legionnaires' disease is a significant public health problem, especially in healthcare settings where patients may be exposed to contaminated environmental sources. Nosocomial outbreaks have been reported worldwide, leading to high morbidity and mortality rates, and increased healthcare costs. This study aimed to compare, the clonal relationship of clinical L. pneumophila strains from two different hospitals with L. pneumophila strains isolated from the water supply.
METHODS
In the period from 2019 to 2021, clinical and environmental strains involved in three cases of legionellosis were compared by means of pulsed field gel electrophoresis and sequence based typing techniques.
RESULTS
Our findings highlight the persistence of clonally distinct strains within each hospital examined. Furthermore, the L. pneumophila strains detected from hospital environmental sources were related to the clinical strains isolated, demonstrating the nosocomial origin of these cases.
CONCLUSIONS
Therefore, it is important to implement more accurate surveillance systems both for epidemiological studies and to check the effectiveness of remediation procedures. (www.actabiomedica.it).
Topics: Humans; Legionnaires' Disease; Cross Infection; Legionella pneumophila; Water Supply; Water
PubMed: 37773490
DOI: 10.23750/abm.v94iS3.15048 -
Indian Journal of Medical Microbiology 2018Legionella pneumophila was first recognised as a fatal cause of pneumonia more than four decades ago, during the 1976-American Legion convention in Philadelphia, USA.... (Review)
Review
Legionella pneumophila was first recognised as a fatal cause of pneumonia more than four decades ago, during the 1976-American Legion convention in Philadelphia, USA. Legionella spp. continue to cause disease outbreaks of public health significance, and at present, Legionnaires' disease (LD) has emerged as an important cause of community and hospital-acquired pneumonia. Parallel to this, the understanding of LD has also increased exponentially. However, the disease is likely to be underreported in many countries because of the dearth of common definitions, diagnostic tests and active surveillance systems. In this review, we outline the basic concepts of Legionella including clinical presentations, epidemiology, laboratory diagnosis and the status of LD in India. This article also summarises the progress of research related to Legionella in this country, identifying the research gaps and discussing priorities to explore this unexplored pathogen in India.
Topics: Biomedical Research; Clinical Laboratory Techniques; Community-Acquired Infections; Cross Infection; Humans; India; Legionella pneumophila; Legionnaires' Disease
PubMed: 30429383
DOI: 10.4103/ijmm.IJMM_18_298 -
Emerging Infectious Diseases Mar 2022Reported Legionnaires' disease (LD) cases began increasing in the United States in 2003 after relatively stable numbers for >10 years; reasons for the rise are unclear.... (Review)
Review
Reported Legionnaires' disease (LD) cases began increasing in the United States in 2003 after relatively stable numbers for >10 years; reasons for the rise are unclear. We compared epidemiologic patterns associated with cases reported to the Centers for Disease Control and Prevention before and during the rise. The age-standardized average incidence was 0.48 cases/100,000 population during 1992-2002 compared with 2.71 cases/100,000 in 2018. Reported LD incidence increased in nearly every demographic, but increases tended to be larger in demographic groups with higher incidence. During both periods, the largest number of cases occurred among White persons, but the highest incidence was in Black or African American persons. Incidence and increases in incidence were generally largest in the East North Central, Middle Atlantic, and New England divisions. Seasonality was more pronounced during 2003-2018, especially in the Northeast and Midwest. Rising incidence was most notably associated with increasing racial disparities, geographic focus, and seasonality.
Topics: Centers for Disease Control and Prevention, U.S.; Humans; Incidence; Legionnaires' Disease; New England; United States
PubMed: 35195513
DOI: 10.3201/eid2803.211435