Legionella Urinary Antigen Test Research Articles

難治性癲癇患者に発症し，診断と抗菌薬選択に苦慮した Acute Respiratory Distress Syndrome（ARDS） 合併重症レジオネラ肺炎の 1 例

A 32-year-old female with epilepsy presented at our hospital with high-grade fever, seizures, and unconsciousness. She was initially treated for aspiration pneumonia with ampicillin/sulbactam. Despite antibiotic therapy, her chest X-ray findings dramatically worsened, showing extension to the bilateral lung field. Her PaO2/FiO2 ratio decreased to 70.6. Rapid progression of hypoxia, unconsciousness, and hyponatremia led to the suspicion of Legionella pneumonia; however, it was difficult to make a definitive diagnosis because she had denied using a whirlpool spa and the initial urinary Legionella antigen test results were negative. Therefore, we repeated the Legionella urinary antigen test, which was positive. On the basis of these results, sputum polymerase chain reaction findings, and the four-fold elevation of paired antibodies, the patient was diagnosed as having Legionella pneumonia accompanied by acute respiratory distress syndrome. We considered administering fluoroquinolone antibiotics, that are recommended for severe Legionella pneumonia, although quinolones have a potential risk for causing convulsions. In this case, we carefully administered ciprofloxacin. The patient recovered consciousness after treatment without any relapse of epileptic seizures. We also administered a corticosteroid for severe pneumonia with the expectation of clinical improvement and to avoid intubation. We emphasize the importance of aggressive workup and empirical therapy for patients with Legionella pneumonia with rapidly worsening symptoms and clinical features such as unconsciousness, epilepsy, and hyponatremia and in whom fluoroquinolone and corticosteroid therapy are effective despite the presence of epilepsy.

Bacteremic pneumonia caused by Nocardia veterana in an HIV-infected patient

Disseminated Nocardia veterana infection has rarely been reported. We describe the first reported case of N. veterana bacteremic pneumonia in an HIV-infected patient. The isolate was confirmed by 16S rRNA sequencing analysis. The patient initially responded well to trimethoprim-sulfamethoxazole treatment (minimum inhibitory concentration 0.25 μg/ml), but died of ventilator-associated pneumonia.

<i>Legionella pneumophila</i> serogroup 3 による呼吸器感染症の4 症例

Legionella pneumonia tends to be severe and is known to be fatal. Introduction of the urinary Legionella antigen test and changes in the Infectious Disease Law have led to increased numbers of reports, and milder cases are now occasionally seen. We experienced three cases demonstrating mild respiratory infections and one case demonstrating nosocomial pneumonia associated by Legionella pneumophila serogroup 3. Case 1 showed multiple ground-glass opacities on HRCT and productive cough. Cases 2 and 3 showed abnormal findings on chest X-ray, and chest CT findings in both cases suggested chronic respiratory infection. Case 4 experienced fever and hypoxia, and pulmonary edema was noted on X-ray. All of them four cases were diagnosed with respiratory infections isolated L. pneumophila serogroup 3 by culture results, and three of them cases were treated in the outpatient clinic. Thus, milder cases of Legionella pneumonia may be encountered during routine care, and tests for Legionella should be performed in such cases.

Novel H1N1 influenza and Panton-Valentine leukocidin Staphylococcus aureus necrotizing pneumonia

The association between seasonal influenza and staphylococcal pneumonia has long been recognized (Chickering and Park, 1919; Roberts et al, 2008), and both meticillin-resistant Staphylococcus aureus and Panton-Valentine leukocidin S. aureus have been associated with seasonal influenza pandemics (Roberts et al, 2008; Kearns et al, 2009; Murray et al, 2010).

Legionnaires' disease mimicking swine influenza (H1N1) pneumonia during the “herald wave” of the pandemic

BackgroundNew York area hospitals were hit hard by the swine influenza (H1N1) pandemic in spring and summer 2009. During a pandemic, the initial cases may be difficult to recognize, but subsequent clinical diagnoses were relatively straightforward, given the high volume of cases and their typical clinical presentation. Swine influenza pneumonia presents as an influenza-like illness (ILI) with dry cough, fever >102°F and myalgias. A variety of other viral pneumonias, eg, cytomegalovirus, human parainfluenza virus 3 (HPIV 3), and adenovirus, as well as bacterial community-acquired pneumonias (CAPs) that may present with some of the clinical and laboratory features of H1N1 pneumonia. Most adults admitted to hospitals with ILIs during the pandemic had, in fact, definite or probable H1N1 pneumonia. The Infectious Disease Division at Winthrop-University Hospital developed a diagnostic weighted point score to identify probable H1N1 cases in hospitalized adults with rapid negative influenza diagnostic tests (RIDTs).MethodsWe present a case of an elderly male who presented with an ILI and negative RIDTs during the H1N1 pandemic. He was admitted with a diagnosis of possible H1N1, and placed on influenza precautions and oseltamivir. Although the patient had features consistent with H1N1 pneumonia, Legionnaires' disease was included in the differential diagnosis because of his elevated serum ferritin levels. A Legionella urinary antigen test was positive for Legionella pneumophila (serogroups 01-06).ResultsThe peak seasonal incidence of sporadic Legionnaires' disease occurs in the summer and fall. Even in the midst of a pandemic, clinicians should be on the alert for other infectious diseases that may mimic H1N1 pneumonia. In our experience, the best way to differentiate H1N1 from ILIs or other bacterial CAPs is through the Winthrop-University Hospital Infectious Disease Division's diagnostic weighted point score system for H1N1 pneumonia or its rapid simplified version, ie, the diagnostic swine influenza triad. Legionnaires' disease is the atypical CAP pathogen most likely to mimic H1N1 pneumonia.ConclusionsBased on this and other nine cases at our institution during the “herald wave” of pandemic, we conclude that Legionnaires' disease may mimic swine influenza (H1N1) pneumonia.

Quantitative real-time PCR tests for diagnostic and prognostic purposes in cases of legionellosis

AbstractThe usefulness of two quantitative real-time PCR assays (qrt-PCRmip targeting Legionella pneumophila, and qrt-PCR16S targeting all Legionella species) performed on lower respiratory tract (LRT) samples for diagnostic and prognostic purposes in 311 patients hospitalized for community-acquired pneumonia (CAP) in Rhône-Alpes (France) was evaluated. The Now Legionella urinary antigen test (UAT) from Binax (Portland, ME, USA) was used as a reference test. Samples were divided into two groups. Group A included 255 CAP patients admitted to Chambery hospital in 2005 and 2006. The Now Legionella UAT was positive in 14 patients. Sensitivities, specificities, positive predictive and negative predictive values for both qrt-PCR tests were 63.6, 98.7, 77.7 and 97.4%, respectively. Group B included 56 consecutive legionellosis patients diagnosed during a 4-year period (2003–2006) at the Grenoble University Hospital. The qrt-PCR16S and qrt-PCRmip displayed a sensitivity of 82.14 and 80.4%, respectively. Among the 70 legionellosis cases, L. pneumophila serogroup 1 was isolated in 15; qrt-PCRmip was positive in another 36, suggesting L. pneumophila infection, whereas the Legionella species involved could not be determined in the remaining 19 cases. The Legionella burden in LRT samples at the time of admission was determined in 46 patients using qrt-PCR16S tests, 44 for qrt-PCR mip groups A and B patients. It varied from 1.9 to 8.35 log10 DNA copies/mL of LRT sample for qrt-PCR16S and from 1.9 to 8.11 log10 DNA copies/mL of sample for qrt-PCRmip. High bacterial loads in LRT samples at hospital admission were significantly associated with higher Fine classes, the need for hospitalization in an intensive care unit and for prolonged hospitalization.

Severe Legionnaires disease complicated by multi-organ dysfunction in a previously healthy patient: a case report

A case of a previously healthy lady with community-acquired pneumonia who progressed to severe acute respiratory distress syndrome, acute renal failure, disseminated intravascular coagulation and sepsis is reported. Treatment with antibiotics and various modes of mechanical ventilation in the intensive care unit were successful. A urinary legionella antigen test was positive for Legionella pneumophila.

Treatment strategies for Legionella infection

Given the nonspecific clinical manifestations of Legionnaires' disease and the high mortality of untreated Legionnaires' disease, we recommend routine use of Legionella testing, especially the Legionella urinary antigen test, for all patients with community-acquired pneumonia. This includes patients with ambulatory pneumonia and hospitalized children. Legionella cultures should be more widely available, especially in hospitals where the drinking water is colonized with Legionella. Azithromycin or levofloxacin can be considered as first-line therapy. Other antibiotics including tetracyclines, tigecycline, other fluoroquinolones and other macrolides (especially clarithromycin) are also effective. The clinical response of quinolones may be somewhat more favorable compared to macrolides, but the outcome is similar. If the Legionnaires' disease is hospital-acquired, culturing of the hospital drinking water for Legionella is indicated.

Impact of the Legionella urinary antigen test on epidemiological trends in community outbreaks of legionellosis in Catalonia, Spain, 1990–2004

To describe the characteristics of community outbreaks of legionellosis in Catalonia, Spain from 1990 to 2004, to compare two time periods (1990-1996 and 1997-2004), and to assess the influence of outbreak characteristics on the case fatality rate (CFR). This is a descriptive analysis of the outbreaks detected by epidemiological surveillance units in Catalonia. Variables potentially related to the CFR were analyzed by logistic regression. Of the 118 outbreaks involving 690 patients (overall CFR 4.5%), the urinary antigen test (UAT) was used for first case diagnosis in 80.5%. The origin of the outbreak was identified as a cooling tower in 35.6%, as a water distribution system in a public building in 14.4%, and a water distribution system at other sites in 7.6%. Statistically significant differences were found in the CFR (12.2% vs. 3.9%; p=0.018) and detection of the first case by UAT (0.0% vs. 87.2%; p<0.001) between the two time periods investigated. Logistic regression showed an increase in the CFR according to outbreak size (adjusted odds ratio (aOR) 1.18; 95% confidence interval (CI) 1.05-1.33) that was significantly lower in the second period (aOR 0.09; 95% CI 0.04-0.20). Since the UAT was introduced, early diagnosis and treatment has helped to improve the outcomes and CFR of cases involved in outbreaks of legionellosis.

The relationship between diagnostic tests and case characteristics in Legionnaires’ disease

In this retrospective study of 332 cases of Legionnaires' disease (LD) in 4 Danish counties between 1995 and 2005 we aimed to compare the sensitivity of culture, PCR, urinary antigen testing, and serology to the mode of acquisition, serogroup, and severity of disease. Furthermore, we analyzed time to diagnosis. Laboratory confirmed cases of LD were found through the national Danish surveillance system and departments of clinical microbiology. In our study PCR was more sensitive (79.2%) than urinary antigen testing (70.4%), serology (54.8%), and culture (39.9%) (p<0.001).The sensitivity of Legionella urinary antigen test was higher among travel-associated cases (90.2%) compared to non-travel-associated cases (65.8%) and hospital acquired cases (45.7%) (p<0.001). Overall, the most common species and serogroup identified was L. pneumophila serogroup 1 (64.3% (110/171)). Community acquired cases with serogroup 1 were diagnosed earlier (mean 5 d, IQR: 4-9 d) than community acquired cases with other species or serogroups (mean 10.5 d, IQR: 5-19.5) (p<0.001). In conclusion, the urinary antigen test, PCR, and culture were conducive to the diagnosis of Legionella infection, and ordering of all 3 tests is recommended to ensure a definite and rapid diagnosis of Legionella.

Legionella pneumophila DNA in serum samples during Legionnaires’ disease in relation to C-reactive protein levels

Legionella pneumophila DNA can be detected in serum from patients with Legionnaires' disease (LD). We explored this observation studying the kinetics of L. pneumophila DNA in serum samples in relation to C-reactive protein (CRP). Eleven hospitalized patients with LD were studied. Diagnosis was made by Legionella urinary antigen test in 8 patients and seroconversion in 3 patients. A macrophage infectivity potentiator (MIP) real-time PCR was performed on 31 serum samples, including 20 follow-up serum samples. Serum samples obtained on the day of admission were MIP PCR-positive in 7 (64%) and MIP PCR-negative in 4 (36%) patients. Three (75%) of the 4 patients with a MIP PCR-negative serum sample on the day of admission became positive during follow-up. Overall, L. pneumophila DNA was detected in serum samples from 10 of the 11 patients (91%). CRP levels in the 7 patients with a positive MIP PCR serum sample on day of admission (499 +/- 144 mg/l; median +/- SD) were significantly higher than those in the 4 patients with a negative MIP PCR serum sample on the day of admission (244 +/- 97 mg/l). No difference in the severity of the disease on the day of admission was found between these patients. The presence of L. pneumophila DNA in serum is a common phenomenon in hospitalized patients with LD, although in some cases it is not yet present on the day of admission. L. pneumophila DNA in serum on the day of admission correlates with high CRP levels, but not with the severity of the disease.

Severe adenovirus community-acquired pneumonia mimicking Legionella

Dear Editor, I read with interest the report of Drs. Hakim and Tleyjah on severe adenovirus pneumonia in your journal [1]. Their literature review reminds us of the reemergence of adenoviral community-acquired pneumonia (CAP) and that it may mimic other causes of CAP, particularly the atypical pneumonias, e.g., Legionnaire’s disease [2, 3]. As the authors correctly state, adenovirus is the only viral cause of CAP that may resemble bacterial pneumonia with focal/ lobar infiltrates or consolidation. However, as with other viral causes of pneumonia, early the chest X-ray in adenoviral CAP may be normal, even when the patient is short of breath and hypoxemic. The two most likely radiologic presentations of adenovirus is a completely normal chest X-ray with hypoxemia and symptoms of pneumonia or with lobar infiltrate/consolidation. Unlike influenza, routinely associated with leukopenia, adenoviral CAP is associated with a normal or elevated white blood cell (WBC) count, excluding viral influenza. An important clue noted by the authors, which has been our experience as well is the presence of conjunctival suffusion when present. Another important point is that viral pneumonias are ordinarily not accompanied by loose stools/diarrhea [4]. Adenovirus is most likely to be confused in this respect with Mycoplasma pneumoniae or Legionnaire’s disease, which is a common feature of both. Adenoviral CAP in patients with lobar infiltrates mimic Legionnaire’s disease, which may be differentiated from Legionella by the absence of hyponatremia, hypophosphatemia, and highly elevated serum levels [5]. As with conjunctival suffusion, an important clue to adenoviral pneumonia is wheezing, more common in children that, if present, should suggest adenovirus [1]. Recently, we have had a case of adenoviral CAP in a normal host different to that reported by the authors. The patient was a 36-year-old immunocompetent male who presented with severe CAP with a prominent dry cough and headache. On physical examination, he had a questionable faint truncal rash and conjunctival suffusion. Auscultation of the chest revealed no rales. His WBC count was 7.3 K/ mm with monocytosis. Relative lymphopenia was not present. His platelet count was 280,000 K/mm. Because of his headache and possible rash, the question of aseptic meningitis was raised and a lumbar puncture was performed. His cerebrospinal fluid (CSF) showed 8 WBCs/hpf with a normal glucose, protein, and lactic acid level. Head magnetic resonance imaging (MRI) was negative. He was hypoxemic on room air. Both his erythrocyte sedimentation rate (ESR) and liver function tests (LFTs) were unelevated and cold agglutinin titers were negative. His creatine phosphokinase (CPK) was unelevated. Titers for Legionella, M. pneumoniae, and Chlamydia pneumoniae were negative. His Legionella urinary antigen test was negative. His adenovirus titer was elevated 1:128 (normal<1:8). As the authors suggest, adenoviral CAP is probably more common than recognized. It is an easily missed diagnosis and should be included in the differential diagnosis of severe CAP in patients. Early on, in immunocompetent CAP patients without pulmonary infiltrates, the differential diagnosis should include influenza and cytoEur J Clin Microbiol Infect Dis (2009) 28:313–315 DOI 10.1007/s10096-008-0611-6

An outbreak of Legionnaires’ disease associated with a circulating bathwater system at a public bathhouse. II: radiological findings of pneumonia

In July 2002, one of the largest outbreaks of Legionnaires' disease associated with a public bathhouse in Japan occurred in Miyazaki. The local government and the University of Miyazaki performed a retrospective investigation of those persons who were considered to have been exposed to Legionella. This investigation provided a unique opportunity to analyze the clinical presentation of patients with outbreak-associated Legionnaires' disease. The purpose of the present study was to analyze high-resolution computerized tomography (HRCT) scans for the characteristic findings of Legionnaires' disease and to evaluate the correlation between the radiological severity on the initial chest X-ray and the outcome of the patients. Radiological findings of HRCT were analyzed in 35 patients. The radiological severity on chest X-ray was evaluated in 69 patients, utilizing the pneumonia scoring system proposed by the Research Committee on Legionnaires' Disease of the Ministry of Health, Labour and Welfare of the Japanese Government. Air-space consolidation, ground-glass opacity, and pleural effusion were common features on HRCT in patients with Legionnaires' disease. Typical HRCT findings showed bilateral multilobar infiltrates in the subpleural areas without centrilobular opacities. Multivariate logistic regression analysis identified male sex, short incubation period, high serum C-reactive protein, high serum alanine aminotransferase, hyponatremia, and positive Legionella urinary antigen test results as independent risk factors for high pneumonia scores. Patients with high pneumonia scores required significantly longer hospitalization and showed poor prognoses.

Colonization ofLegionellaSpecies in Hotel Water Systems in Turkey

The goal of this study was to evaluate the prevalence of Legionella species in hotel water distribution systems in Alanya, Turkey, which is an important tourism center. Water and swab samples were obtained from 52 Turkish hotels from August 2003 to September 2005. Water samples were collected in 100 mL sterile containers and were concentrated by membrane filters with a pore size of 0.45 microm. Heat treatment was used to eliminate other microorganisms from the samples, which were then spread on buffered charcoal yeast extract alpha agar plates and glycine, vancomycin, polymyxin, cycloheximide agar plates. Cysteine-dependent colonies were identified by latex agglutination. In all, 491 water and swab samples were analyzed. The results of all samples were negative for Legionella in 16 (30.8%) hotels. Legionella species (92.5% of which were Legionella pneumophila) were detected in 93 (18.9%) of the samples. The most frequently isolated species were L pneumophila serogroups 6 (63.5%) and 1 (21.5%). Legionella pneumophila serogroup 6 was the most common isolate detected in Turkish hotel water systems in our study. The result of Legionella urinary antigen tests, which are the diagnostic tests most often used to identify legionnaires' disease, may be negative in people infected with L pneumophila serogroup 6. We suggest that clinicians should apply the whole spectrum of laboratory methods for the detection of legionnaires' disease in patients with pneumonia of unknown origin and history of travel to Alanya, Turkey.

Usefulness of aetiological tests for guiding antibiotic therapy in community-acquired pneumonia

The goal with antibiotic therapy in community-acquired pneumonia (CAP) is to cure the patient, ideally without causing side effects and without contributing to the further development of antibiotic resistance. Although patients with severe CAP should be treated with broad-spectrum antibiotics, patients with non-severe CAP should preferably receive pathogen-directed therapy. Rapid aetiological tests, such as sputum Gram stain and urinary antigen tests, are useful for targeting initial pathogen-directed therapy. Non-rapid tests, such as cultures, can subsequently support a switch from initial broad-spectrum therapy to narrow-spectrum therapy and direct therapy changes in case of treatment failure. As conventional diagnostic methods often fail to identify the aetiology of CAP, PCR (polymerase chain reaction) tests for respiratory pathogens have become useful and should be further developed. Based on the test specificities, aetiological tests may provide diagnoses with varying reliability, i.e. definite aetiologies (e.g., blood culture and Legionella urinary antigen test), probable aetiologies (e.g., sputum culture and PCR for Mycoplasma pneumoniae), or possible aetiologies (e.g., culture of nasopharyngeal secretions and PCR for Streptococcus pneumoniae). A definite or probable aetiology can often be used to target antibiotic therapy.

Active Surveillance of Legionnaires Disease During a Prospective Observational Study of Community-and Hospital-Acquired Pneumonia

A prospective surveillance study of legionnaires disease and an environmental survey of Legionella species were performed simultaneously in a general hospital. During a period of 3 years, 705 patients with pneumonia were screened with a Legionella urinary antigen test, and pneumonia was confirmed by culture and serological tests. Twelve cases of legionnaires disease were identified, none of which were hospital acquired, despite the fact that 60% of hospital water samples were contaminated with Legionella pneumophila at a concentration of more than 10(3) colony-forming units/L. The probable source of infection was identified for only 2 community-acquired cases. The results show that environmental contamination alone is not able to predict the risk of legionnaires disease. If no cases are present, monitoring of hospital water systems is of little significance; clinical surveillance is much more important.

Investigation of an outbreak of Legionnaires’ disease: Hereford, UK 2003

This report describes the investigation and control of a community outbreak of Legionnaires' disease in Hereford, UK, in November 2003. Outbreak investigation consisted of epidemiological survey, identification and environmental investigation of potential sources, microbiological analysis of clinical and environmental samples and mapping the location of potential sources and the movement and residence of cases. Each identified source was allocated a 'composite score' based on different zones of exposure and wind direction. Altogether, 28 cases were identified, with an overall case fatality rate of 7%. All cases had epidemiological links to Hereford city centre. The 'composite score' identified a cluster of cooling towers as being the most likely source of the outbreak. Environmental samples from one of the cooling towers in the cluster and clinical samples from two patients were positive for Legionella pneumophilia serogroup 1 and were indistinguishable by molecular sub-typing. In this outbreak, the use of microbiological, environmental and epidemiological techniques facilitated the rapid identification of a cooling tower as the source of this outbreak. This study illustrates the continuing importance of cooling towers as a source of Legionnaires' disease and the utility of obtaining and comparing both clinical and environmental samples.

Severe Sepsis and Acute Respiratory Distress Syndrome From Community-Acquired Legionella Pneumonia: Case Report

A case of a young man with community-acquired pneumonia, severe acute respiratory distress syndrome, and sepsis is reported. Treatment with antibiotics and various modes of mechanical ventilation in the intensive care unit were unsuccessful. A urinary legionella antigen test was positive for Legionella pneumophila.

Evaluation of Rapid U Legionella Plus Test, a new immunochromatographic assay for detection of Legionella pneumophila serogroup 1 antigen in urine

Since antigen detection in urine has proved to be a sensitive and rapid method for detecting L. pneumophila serogroup 1, this technique has become one of the most frequently used tools for diagnosing Legionnaires’ disease (LD) [1]. Currently, there are several commercially available tests for detecting L. pneumophila antigen in urine [2, 3]. Commercial kits that use enzyme immunoassay (EIA) methodologies have been available for several years and perform similarly. One immunochromatographic (ICT) assay (Binax NOW Legionella Urinary Antigen Test; Binax, Portland, Maine, USA) has similar sensitivity and specificity to EIA [2]. ICT assays have important advantages over conventional EIAs: the tests are simple to perform, they do not require special laboratory equipment, and results can be obtained within 15 min. The aim of the study presented here was to evaluate a newly developed ICT urine antigen test (the Rapid U Legionella Plus Test; Diamondial, Sees, France), for its ability to detect L. pneumophila serogroup 1 in urine. We evaluated the ability of the new antigen test to detect LD in a well-described sample of patients with and without LD using frozen urine samples. The samples had been collected between 1997 and 2005 and stored at −70°C until processing. We included 71 urine samples obtained from 71 patients with LD (cases). A case of LD was defined as a patient with pneumonia who had radiological signs of infiltration and laboratory evidence of infection with L. pneumophila. Laboratory evidence included one or more of the following criteria: isolation of L. pneumophila from a lower respiratory tract (LRT) sample; a positive PCR result on a LRT sample using a 16S rRNA-based assay [4]; seroconversion to positive IgM and/or IgG antibodies against L. pneumophila in paired acute-phase and convalescentphase sera using a commercial ELISA (Serion ELISA; Institut Virion\Serion, Wurzburg, Germany). All LD-positive samples tested negative for pneumococcal antigen in urine (PAG; Binax NOW, Portland, Maine, USA). Urine samples of 91 patients with respiratory tract infections caused by pathogens other than Legionella were tested in a similar manner to test specificity. All patients were tested for LD using an immunochromatographic assay (Binax NOW); all samples tested negative. The laboratory results for these patients tested with blood cultures (blood), PAG detection in urine (PAG) and sputum culture (sputum) were as follows: Streptococcus pneumoniae (n=52 patients: detected in sputum in 8 patients, in blood and PAG in 23, and in blood alone in 21), Haemophilus influenzae (n=10: blood, 3; sputum, 7), Moraxella catarralis (n=3: all in sputum), Staphylococcus aureus (n=4: blood and sputum, 2; sputum, 2), Escherichia coli (n=2: blood and sputum, 1; sputum alone, 1), Acinetobacter baumannii (n=1: blood and sputum), Streptococcus pyogenes (n=2: both blood and sputum), Klebsiella pneumoniae (n=1: sputum), Mycobacterium tuberculosis (n=3: all sputum), Pneumocystis jirovecii (n=1: Giemsa and silver-stain positive). Twelve patients with a fourfold or greater rise in (complement-fixating) antibodies against influenza A virus (n=3), adenovirus (n=1), Chlamydia psittaci (n=3), Mycoplasma pneumoniae (n=4) and parainfluenza virus (n=1) were included. The presence of L. pneumophila antigen in urine samples was investigated using Rapid U Legionella Plus Test, a qualitative ICT assay. We compared the sensitivity and specificity of this test with that of a widely used ICT assay, the Binax Now urinary antigen test (Binax NOW). Eur J Clin Microbiol Infect Dis (2006) 25:733–735 DOI 10.1007/s10096-006-0213-0

Clinical Relevance of Positive NOWTMLegionellaUrinary Antigen Test in a Tertiary-Care Hospital in Korea

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. 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. 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. 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.