The principal mode of the transmission of Legionnaires disease is an inhalation of the cooling tower water droplets in which Legionellae exist. As a central cooling system is popularized in many public buildings and large buildings nowadays, the number of cooling towers in rapidly increasing. Therefore the possibility of an outbreak of Legionnaires disease is likely increased. To determine the presence of Legionella in cooling tower water as the first step for the prevention of Legionnaires disease, 48 samples of cooling tower water were taken from 24 buildings in Taegu city in July and September 1987. Three samples out of 24 water samples in September yielded Legionella but it was not isolated in the samples of July. Isolated 3 Legionellas were identified as Legionella peumophila. It seems that Legionella from the cooling tower will be isolated more frequently in late summer than early because central cooling system is stopped operation during winter season which in cool. As based on our survey, Legionnaires disease can occur in Taegu city and if it happens it is most likely due to L. pneumophila.
Daegu ; Inhalation ; Legionella* ; Legionnaires' Disease ; Seasons ; Water*

Aim: The aim of this study was to monitor the restricted water systems during the period of COVID-19 lockdown for the waterborne pathogen Legionella pneumophila. Selected water systems were monitored to evaluate the effect of stagnation in terms of Legionella colonization. Methodology and results: A total of 160 water samples were taken from buildings which were temporarily shut down or had restricted usage between April-December 2020. None of the sampling points had Legionella positive history in the last three years. All water samples were tested using classic microbiological culture as the gold standard and rapid Vermicon ScanVIT Legionella test kit combined with epifluorescence microscopy. Sixteen (10%) out of 160 water samples were recorded as Legionella-positive by both methods, where none of them was positive before the COVID-19 lockdown. All positives were tested as L. pneumophila serogroup 1 with latex agglutination kit. Conclusion, significance and impact of study Colonization of Legionella in stagnant water systems occurs rapidly. Before reopening, routine monitoring in buildings is extremely important especially under restricted use or closure is in case. Flushing, disinfecting and testing are crucial for minimizing the health risks for the public health.
Legionella ; Sanitary Engineering ; COVID-19 ; Waterborne Diseases ; Legionnaires' ; Disease

Adolescent ; Adult ; China ; epidemiology ; Disease Outbreaks ; Female ; Humans ; Incidence ; Legionnaires' Disease ; classification ; epidemiology ; transmission ; Male

Legionella species are abundant in the built environment and are increasingly recognized as a cause of Legionnaires' disease (LD). As the number of cases of Legionnaires' disease acquired by local communities in the Seoul metropolitan area in Korea has been increased, there was concern that changes in environmental factors could affect disease outbreaks. We described the association between climatic variables and occurrence of legionellosis in Korea and Legionella detection rate in Seoul area. A total of 418 cases of legionellosis were reported between 2014 and 2017. There was a seasonal peak in summer. LD continuously occurred from early spring to winter every year and rapidly increased in summer. In the regression analysis, the primary variables of interest- PM2.5 (µg/m³), NO₂ (ppb), and a number of the date of issue O₃ warning were not significant except for average temperature (R²=0.8075). The Legionella detection rate in Seoul, Korea showed a trend similar to precipitation (P=0.708, ANOVA). A relatively high proportion of Legionella detection rate was shown, especially cooling tower (17.7%) and public bath (19.3%). This finding is in line with current understanding of the ecological profile of this pathogen and supports the assertion that legionellosis occurs through contamination of water sources.
Baths ; Disease Outbreaks ; Epidemiology ; Korea ; Legionella ; Legionellosis ; Legionnaires' Disease ; Regression Analysis ; Seasons ; Seoul ; Water

The harshness of legionellosis differs from mild Pontiac fever to potentially fatal Legionnaire's disease. The increasing development of drug resistance against legionellosis has led to explore new novel drug targets. It has been found that phosphoglucosamine mutase, phosphomannomutase, and phosphoglyceromutase enzymes can be used as the most probable therapeutic drug targets through extensive data mining. Phosphoglucosamine mutase is involved in amino sugar and nucleotide sugar metabolism. The purpose of this study was to predict the potential target of that specific drug. For this, the 3D structure of phosphoglucosamine mutase of Legionella pneumophila (strain Paris) was determined by means of homology modeling through Phyre2 and refined by ModRefiner. Then, the designed model was evaluated with a structure validation program, for instance, PROCHECK, ERRAT, Verify3D, and QMEAN, for further structural analysis. Secondary structural features were determined through self-optimized prediction method with alignment (SOPMA) and interacting networks by STRING. Consequently, we performed molecular docking studies. The analytical result of PROCHECK showed that 95.0% of the residues are in the most favored region, 4.50% are in the additional allowed region and 0.50% are in the generously allowed region of the Ramachandran plot. Verify3D graph value indicates a score of 0.71 and 89.791, 1.11 for ERRAT and QMEAN respectively. Arg419, Thr414, Ser412, and Thr9 were found to dock the substrate for the most favorable binding of S-mercaptocysteine. However, these findings from this current study will pave the way for further extensive investigation of this enzyme in wet lab experiments and in that way assist drug design against legionellosis.
Computer Simulation* ; Data Mining ; Drug Delivery Systems ; Drug Design ; Drug Resistance ; Fever ; Legionella pneumophila* ; Legionellosis* ; Legionnaires' Disease ; Metabolism ; Phosphoglycerate Mutase

BACKGROUND: The morbidity and mortality of Legionnaires' disease are not established in Korea, because patients with community-acquired pneumonia (CAP) have rarely been investigated for Legionella. An assay for Legionella antigen in urine has been approved as one of the diagnostic criteria of Legionnaires' disease. Binax Now(TM) Legionella Urinary Antigen Test (LUA) was introduced in Asan Medical Center in July 2002. The purpose of this study was to evaluate the clinical relevance of positive LUA. METHODS: During the 39-month period from July 2002 to September 2005, the medical records of LUA-positive patients were reviewed for demographic findings, laboratory findings, clinical diagnosis, antimicrobial treatment, outcome, and acquisition of infections. Diagnosis of Legionnaires' disease was based on National Nosocomial Infections Surveillance (NNIS) criteria for defining nosocomial pneumonia. RESULTS: Seven (0.3%) of the 2443 patients tested for LUA were positive. All 7 patients were consistent with the diagnostic criteria of Legionnaires' disease; six patients were diagnosed with CAP and one patient was admitted due to nosocomial pneumonia. Six patients were treated with azithromycin or ciprofloxacin but one patient was not treated for Legionella infection. With the report of LUApositive results, a Legionella-targeted treatment was started in two patients and an inappropriate empirical therapy was ceased in one patient. All patients treated with Legionella-targeted treatment improved clinically except one who died of adult respiratory distress syndrome at the first hospital day. CONCLUSIONS: Positive LUA is useful in diagnosing Legionnaire's disease at an early stage and in helping to initiate appropriate treatments in a tertiary-care hospital in Korea.
Azithromycin ; Chungcheongnam-do ; Ciprofloxacin ; Cross Infection ; Diagnosis ; Humans ; Korea* ; Legionella* ; Legionnaires' Disease ; Medical Records ; Mortality ; Pneumonia ; Respiratory Distress Syndrome, Adult

Legionella pneumonia (LP) is a rare systemic infectious disease, which is often misdiagnosed by clinicians due to the atypical symptoms. A middle-aged man who suffered from fever and dyspnea was diagnosed as community acquired pneumonia (CAP) in Changsha Central Hospital in March 2015. The treatment was unsatisfied firstly. The patients showed further symptoms of rhabdomyolysis, acute liver and renal failure, and impaired neural functions, who was diagnosed as LP with multiple organ failure based on a positive test for Legionella antibody. The patient was recovered after treated with moxifloxacin combined with azithromycin and continuous renal replacement therapy. LP should be paid attention when patient was diagnosed as CAP and failed to be treated. The satisfied outcome is achieved after application of macrolide, quinolones and comprehensive treatments.
Anti-Bacterial Agents ; Community-Acquired Infections ; Fluoroquinolones ; Humans ; Legionella ; Legionnaires' Disease ; Male ; Middle Aged ; Moxifloxacin ; Multiple Organ Failure ; Pneumonia, Bacterial

OBJECTIVES: Legionnaires' disease (LD) is a severe type of pneumonia caused by inhalation of aerosols contaminated with Legionella. On September 22, 2016, a single case of LD was reported from a newly built apartment building in Gyeonggi province. This article describes an epidemiologic investigation of LD and identification of the possible source of infection. METHODS: To identify the source of LD, we interviewed the patient's husband using a questionnaire based on the Legionella management guidelines from the Korea Centers for Disease Control and Prevention. Water samples from the site were collected and analyzed. An epidemiological investigation of the residents and visitors in the apartment building was conducted for 14 days before the index patient's symptoms first appeared to 14 days after the implementation of environmental control measures. RESULTS: Legionella pneumophila serogroup 1 was isolated from the heated-water samples from the patient's residence and the basement of the apartment complex. Thirty-two suspected cases were reported from the apartment building during the surveillance period, yet all were confirmed negative based on urinary antigen tests. CONCLUSIONS: The likely source of infection was the building's potable water, particularly heated water. Further study of effective monitoring systems in heated potable water should be considered.
Aerosols ; Centers for Disease Control and Prevention (U.S.) ; Disease Outbreaks ; Drinking Water ; Gyeonggi-do ; Hot Temperature ; Humans ; Inhalation ; Korea ; Legionella ; Legionella pneumophila ; Legionnaires' Disease ; Pneumonia ; Serogroup ; Spouses ; Water

BACKGROUND: Legionella pneumophila has been recognized as an important cause of community-acquired pneumonia(CAP) requiring hospitalization. However, epidemiological data on the occurrence of legionella-related pneumonia is unavailable in Korea. The purpose of this study was to evaluated the etiological imprtance of legionella pneumophila serogroup 1 in patients hospitalized with CAP. METHOD: The CAP patient over 16 year-old were recruited from July 1999 to June 2000 at the Chunchon Sacred Heart Hospital. Fifty four patients (male 29, female 25, average age 63.8±15.3) were included in this study. A diagnosis of a legionella pneumophila infection was based on a urinary antigen test using the Binax Company enzyme immunoassay. The severity of pneumonia was assessed using the Fine's PORT scoring system. RESULT: The average Fine's PORT score was 99.7(±44.9). According to the risk classification proposed by the Infectious Disease Society of America, the number of patients in each class(from class I to class V) were 6(11.1%), 13(24.1%), 9(16.7%), 14(25.8%), and 12(22.2%), respectively. Thirty two patients(59.3%) were initially admitted to the intensive care unit. The mortality rate was 16.7%(9 in 54). In all patients, urinary antigens to Legionella pneumophila serogroup 1 were not detected. CONCLUSION: Legionella pneumophila may play little role in causing adult CAP in Korea. Therefore, the routine use of macrolide in the empirical treatment of the CAP patients based upon the ATS guidelines(1993) in Korea should be reevaluated.
Adult ; Americas ; Classification ; Communicable Diseases ; Diagnosis ; Female ; Gangwon-do ; Heart ; Hospitalization ; Humans ; Immunoenzyme Techniques ; Intensive Care Units ; Korea* ; Legionella pneumophila* ; Legionella* ; Legionnaires' Disease ; Mortality ; Pneumonia*

Antigens, Bacterial ; immunology ; urine ; Child ; Child, Preschool ; Female ; Humans ; Legionella pneumophila ; immunology ; Legionnaires' Disease ; diagnosis ; immunology ; Male ; Respiratory Tract Infections ; immunology