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Heliyon Jun 2024is the causative agent of Legionnaires' disease, and its prevalence in potable water is a significant public health issue. Water stagnation within buildings increases...
Increased flushing frequency of a model plumbing system initially promoted the formation of viable but non culturable cells but ultimately reduced the concentration of culturable and total DNA.
is the causative agent of Legionnaires' disease, and its prevalence in potable water is a significant public health issue. Water stagnation within buildings increases the risk of However, there are limited studies investigating how stagnation arising through intermittent usage affects proliferation and the studies that are available do not consider viable but non culturable (VBNC) . This study used a model plumbing system to examine how intermittent water stagnation affects both VBNC and culturable . The model plumbing system contained a water tank supplying two biofilm reactors. The model was initially left stagnant for ≈5 months (147 days), after which one reactor was flushed daily, and the other weekly. Biofilm coupons, and water samples were collected for analysis at days 0, 14 and 28. These samples were analysed for culturable and VBNC , free-living amoebae, and heterotrophic bacteria. After 28 days, once-a-day flushing significantly ( < 0.001) reduced the amount of biofilm-associated culturable (1.5 log reduction) compared with weekly flushing. However, higher counts of biofilm-associated VBNC (1 log higher) were recovered from the reactor with once-a-day flushing compared with weekly flushing. Likewise, once-a-day flushing increased the population of biofilm-associated (approximately 3 log higher) compared with weekly flushing, which indicated a positive relationship between VBNC and . This is the first study to investigate the influence of stagnation on VBNC under environmental conditions. Overall, this study showed that a reduction in water stagnation decreased culturable but not VBNC .
PubMed: 38933949
DOI: 10.1016/j.heliyon.2024.e32334 -
Cureus May 2024Legionnaires' disease is an atypical pneumonia caused by species are found in freshwater sources and are transmitted through inhalation of contaminated aerosols....
Legionnaires' disease is an atypical pneumonia caused by species are found in freshwater sources and are transmitted through inhalation of contaminated aerosols. Patients commonly present with fever, chills, and cough. However, in immunosuppressed patients or severe cases, the disease can lead to multiorgan failure. In recent years, the incidence of Legionnaires' disease has drastically increased and unfortunately is commonly underdiagnosed. Gold-standard diagnosis is made through sputum cultures; however, urine antigen remains the most common test used for diagnosis. Goal-directed care includes antibiotics and supportive care. This case highlights a rare and unique presentation of Legionnaires' disease presenting with an elevated 2:1 aspartate aminotransferase to alanine transaminase pattern, typically seen with alcoholic hepatitis.
PubMed: 38910759
DOI: 10.7759/cureus.60856 -
The Lancet. Digital Health Jul 2024Cooling towers containing Legionella spp are a high-risk source of Legionnaires' disease outbreaks. Manually locating cooling towers from aerial imagery during outbreak...
BACKGROUND
Cooling towers containing Legionella spp are a high-risk source of Legionnaires' disease outbreaks. Manually locating cooling towers from aerial imagery during outbreak investigations requires expertise, is labour intensive, and can be prone to errors. We aimed to train a deep learning computer vision model to automatically detect cooling towers that are aerially visible.
METHODS
Between Jan 1 and 31, 2021, we extracted satellite view images of Philadelphia (PN, USA) and New York state (NY, USA) from Google Maps and annotated cooling towers to create training datasets. We augmented training data with synthetic data and model-assisted labelling of additional cities. Using 2051 images containing 7292 cooling towers, we trained a two-stage model using YOLOv5, a model that detects objects in images, and EfficientNet-b5, a model that classifies images. We assessed the primary outcomes of sensitivity and positive predictive value (PPV) of the model against manual labelling on test datasets of 548 images, including from two cities not seen in training (Boston [MA, USA] and Athens [GA, USA]). We compared the search speed of the model with that of manual searching by four epidemiologists.
FINDINGS
The model identified visible cooling towers with 95·1% sensitivity (95% CI 94·0-96·1) and a PPV of 90·1% (95% CI 90·0-90·2) in New York City and Philadelphia. In Boston, sensitivity was 91·6% (89·2-93·7) and PPV was 80·8% (80·5-81·2). In Athens, sensitivity was 86·9% (75·8-94·2) and PPV was 85·5% (84·2-86·7). For an area of New York City encompassing 45 blocks (0·26 square miles), the model searched more than 600 times faster (7·6 s; 351 potential cooling towers identified) than did human investigators (mean 83·75 min [SD 29·5]; mean 310·8 cooling towers [42·2]).
INTERPRETATION
The model could be used to accelerate investigation and source control during outbreaks of Legionnaires' disease through the identification of cooling towers from aerial imagery, potentially preventing additional disease spread. The model has already been used by public health teams for outbreak investigations and to initialise cooling tower registries, which are considered best practice for preventing and responding to outbreaks of Legionnaires' disease.
FUNDING
None.
Topics: Humans; Disease Outbreaks; Legionnaires' Disease; Deep Learning; Air Conditioning; Philadelphia; New York; Legionella; Satellite Imagery
PubMed: 38906615
DOI: 10.1016/S2589-7500(24)00094-3 -
Przeglad Epidemiologiczny Jun 2024Legionnaires' disease is a type of severe pneumonia caused by Legionella bacteria. The case fatality rate in this disease is 5-10%. People with various comorbidities,...
BACKGROUND
Legionnaires' disease is a type of severe pneumonia caused by Legionella bacteria. The case fatality rate in this disease is 5-10%. People with various comorbidities, smokers and the elderly are at greater risk of developing the disease.
OBJECTIVE
The aim of the work is to present the results of an epidemiological investigation into the outbreak of Legionnaires' disease that occurred in the city of Rzeszów and the surrounding area in August and September 2023 and to present the threat related to the presence of Legionella bacteria in water supply installations and networks.
MATERIAL AND METHODS
The material for this publication was data from an epidemiological investigation conducted in the outbreak of Legionnaires disease in Rzeszów in 2023.
RESULTS
Epidemiological investigation revealed 165 cases of Legionnaires' disease in the outbreak, including 152 confirmed cases and 13 probable cases. The case fatality rate in a legionellosis outbreak was 15%. Environmental tests were carried out in residential and public buildings and industrial installations during the investigation. As part of environmental tests, 187 water samples were collected, including 87 warm water samples.
CONCLUSIONS
The outbreak of Legionnaires' disease in the city of Rzeszów draws attention to the potential threat from the Legionella bacteria to the health and life of especially elderly people suffering from chronic diseases. The environmental tests carried out confirmed the highest number of Legionella bacteria at medium and high levels in water samples taken in the private apartments of sick people. Despite the lack of strict legal regulations clearly specifying the obligations regarding periodic disinfection of internal hot water supply installations, cooperation with their owners should be undertaken to enforce plans and actions in this area.
Topics: Humans; Legionnaires' Disease; Disease Outbreaks; Male; Female; Aged; Poland; Middle Aged; Water Microbiology; Adult; Water Supply; Aged, 80 and over; Legionella pneumophila; Legionella
PubMed: 38904311
DOI: 10.32394/pe/188372 -
International Journal of Rheumatic... Jun 2024
Topics: Humans; Myositis; Diagnosis, Differential; Legionnaires' Disease; Treatment Outcome; Predictive Value of Tests; Male; Middle Aged; Female
PubMed: 38881296
DOI: 10.1111/1756-185X.15213 -
BMC Pulmonary Medicine Jun 2024Legionella pneumonia is one of the most severe types of atypical pneumonia, impairing multiple organ systems, posing a threat to life. Diagnosing Legionella pneumonia is...
BACKGROUND
Legionella pneumonia is one of the most severe types of atypical pneumonia, impairing multiple organ systems, posing a threat to life. Diagnosing Legionella pneumonia is challenging due to difficulties in culturing the bacteria and limitations in immunoassay sensitivity and specificity.
CASE PRESENTATION
This paper reports a rare case of sepsis caused by combined infection with Legionella pneumophila and Fusobacterium necrophorum, leading to respiratory failure, acute kidney injury, acute liver injury, myocardial damage, and electrolyte disorders. In addition, we systematically reviewed literature on patients with combined Legionella infections, analyzing their clinical features, laboratory results and diagnosis.
CONCLUSIONS
For pathogens that require prolonged incubation periods and are less sensitive to conventional culturing methods, metagenomic next-generation sequencing (mNGS) can be a powerful supplement to pathogen screening and plays a significant role in the auxiliary diagnosis of complex infectious diseases.
Topics: Humans; High-Throughput Nucleotide Sequencing; Legionella pneumophila; Legionnaires' Disease; Fusobacterium Infections; Fusobacterium necrophorum; Coinfection; Metagenomics; Male; Middle Aged; Pneumonia, Bacterial
PubMed: 38867173
DOI: 10.1186/s12890-024-03097-4 -
Cureus May 2024Legionnaires' disease is a potentially severe type of pneumonia most often caused by the organism . Exposure to this bacterial pathogen typically happens in the...
Legionnaires' disease is a potentially severe type of pneumonia most often caused by the organism . Exposure to this bacterial pathogen typically happens in the community but may also occur in the hospital setting. This report describes the case of a patient who presented due to 10 days of fever, shortness of breath, and diarrhea, with initial imaging demonstrating multifocal pneumonia. The patient was appropriately started on empiric antibiotics for community-acquired pneumonia and admitted to the medicine floor. The patient showed no meaningful improvement in his initial hospital course on empiric antibiotics with continued oxygen requirements. Meanwhile, urine Legionella antigen testing returned positive on hospital day four, and after tailoring antibiotics accordingly, the patient's clinical status improved significantly. This case report highlights the efficacy of broad testing in the initial admission and the need for constant re-evaluation in the context of a patient not improving with appropriate therapy.
PubMed: 38854237
DOI: 10.7759/cureus.59979 -
Nature Communications Jun 2024Bacterial adhesion is a fundamental process which enables colonisation of niche environments and is key for infection. However, in Legionella pneumophila, the causative...
Bacterial adhesion is a fundamental process which enables colonisation of niche environments and is key for infection. However, in Legionella pneumophila, the causative agent of Legionnaires' disease, these processes are not well understood. The Legionella collagen-like protein (Lcl) is an extracellular peripheral membrane protein that recognises sulphated glycosaminoglycans on the surface of eukaryotic cells, but also stimulates bacterial aggregation in response to divalent cations. Here we report the crystal structure of the Lcl C-terminal domain (Lcl-CTD) and present a model for intact Lcl. Our data reveal that Lcl-CTD forms an unusual trimer arrangement with a positively charged external surface and negatively charged solvent exposed internal cavity. Through molecular dynamics simulations, we show how the glycosaminoglycan chondroitin-4-sulphate associates with the Lcl-CTD surface via distinct binding modes. Our findings show that Lcl homologs are present across both the Pseudomonadota and Fibrobacterota-Chlorobiota-Bacteroidota phyla and suggest that Lcl may represent a versatile carbohydrate-binding mechanism.
Topics: Glycosaminoglycans; Bacterial Proteins; Molecular Dynamics Simulation; Legionella pneumophila; Protein Binding; Collagen; Crystallography, X-Ray; Chondroitin Sulfates; Bacterial Adhesion; Protein Domains; Legionnaires' Disease; Humans; Amino Acid Sequence
PubMed: 38851738
DOI: 10.1038/s41467-024-49255-4 -
Frontiers in Cellular and Infection... 2024, one of the main pathogens that causes community-acquired pneumonia, can lead to , a condition characterized predominantly by severe pneumonia. This disease, caused by...
, one of the main pathogens that causes community-acquired pneumonia, can lead to , a condition characterized predominantly by severe pneumonia. This disease, caused by the bacterium , can quickly progress to critical pneumonia and is often associated with damage to multiple organs. As a result, it requires close attention in terms of clinical diagnosis and treatment. Omadacycline, a new type of tetracycline derivative belonging to the aminomethylcycline class of antibiotics, is a semi-synthetic compound derived from minocycline. Its key structural feature, the aminomethyl modification, allows omadacycline to overcome bacterial resistance and broadens its range of effectiveness against bacteria. Clinical studies have demonstrated that omadacycline is not metabolized in the body, and patients with hepatic and renal dysfunction do not need to adjust their dosage. This paper reports a case of successful treatment of with omadacycline in a patient who initially did not respond to empirical treatment with moxifloxacin. The patient also experienced electrolyte disturbance, as well as dysfunction in the liver and kidneys, delirium, and other related psychiatric symptoms.
Topics: Humans; Tetracyclines; Anti-Bacterial Agents; Legionnaires' Disease; Legionella pneumophila; Treatment Outcome; Male; Community-Acquired Infections; Moxifloxacin; Middle Aged
PubMed: 38836055
DOI: 10.3389/fcimb.2024.1380312 -
Water Research Aug 2024Legionella is an opportunistic waterborne pathogen that causes Legionnaires' disease. It poses a significant public health risk, especially to vulnerable populations in...
Legionella is an opportunistic waterborne pathogen that causes Legionnaires' disease. It poses a significant public health risk, especially to vulnerable populations in health care facilities. It is ubiquitous in manufactured water systems and is transmitted via inhalation or aspiration of aerosols/water droplets generated from water fixtures (e.g., showers and hand basins). As such, the effective management of premise plumbing systems (building water systems) in health care facilities is essential for reducing the risk of Legionnaires' disease. Chemical disinfection is a commonly used control method and chlorine-based disinfectants, including chlorine, chloramine, and chlorine dioxide, have been used for over a century. However, the effectiveness of these disinfectants in premise plumbing systems is affected by various interconnected factors that can make it challenging to maintain effective disinfection. This systematic literature review identifies all studies that have examined the factors impacting the efficacy and decay of chlorine-based disinfectant within premise plumbing systems. A total of 117 field and laboratory-based studies were identified and included in this review. A total of 20 studies directly compared the effectiveness of the different chlorine-based disinfectants. The findings from these studies ranked the typical effectiveness as follows: chloramine > chlorine dioxide > chlorine. A total of 26 factors were identified across 117 studies as influencing the efficacy and decay of disinfectants in premise plumbing systems. These factors were sorted into categories of operational factors that are changed by the operation of water devices and fixtures (such as stagnation, temperature, water velocity), evolving factors which are changed in-directly (such as disinfectant concentration, Legionella disinfectant resistance, Legionella growth, season, biofilm and microbe, protozoa, nitrification, total organic carbon(TOC), pH, dissolved oxygen(DO), hardness, ammonia, and sediment and pipe deposit) and stable factors that are not often changed(such as disinfectant type, pipe material, pipe size, pipe age, water recirculating, softener, corrosion inhibitor, automatic sensor tap, building floor, and construction activity). A factor-effect map of each of these factors and whether they have a positive or negative association with disinfection efficacy against Legionella in premise plumbing systems is presented. It was also found that evaluating the effectiveness of chlorine disinfection as a water risk management strategy is further complicated by varying disinfection resistance of Legionella species and the form of Legionella (culturable/viable but non culturable, free living/biofilm associated, intracellular replication within amoeba hosts). Future research is needed that utilises sensors and other approaches to measure these key factors (such as pH, temperature, stagnation, water age and disinfection residual) in real time throughout premise plumbing systems. This information will support the development of improved models to predict disinfection within premise plumbing systems. The findings from this study will inform the use of chlorine-based disinfection within premise plumbing systems to reduce the risk of Legionnaires disease.
Topics: Disinfectants; Chlorine; Legionella; Disinfection; Chlorine Compounds; Water Microbiology; Chloramines; Water Supply; Oxides; Water Purification
PubMed: 38824796
DOI: 10.1016/j.watres.2024.121794