Levofloxacin Efficacy in the Treatment of Community-Acquired Legionellosis

Uncovering Gaps in Knowledge: A Survey of Belgian General Practitioners' Awareness of Legionnaires' Disease Diagnostic Testing

Background: The incidence of Legionnaires' disease (LD) is increasing steadily in Europe. Its early diagnosis by general practitioners (GPs) is crucial for better patient outcomes. Study objectives: This study assessed Belgian GPs' knowledge about LD and the accessibility of diagnostic tests in their practices. Methods: A specifically designed questionnaire was distributed to actively practicing GPs, including primary care trainees, between 31 January 2022 and 13 March 2022. This survey targeted approximately 4200 GPs with an estimated population catchment of 30% of the actively working Belgian GPs. Results: The response rate was estimated at 3%. Over 70% of the GPs correctly identified the LD occurrence peak, major risk factors, and clinical manifestations. While 62% of participants preferred the Legionella pneumophila urinary antigen test (UAT) as a primary diagnostic method, 75% were unsure about its availability within their laboratories and 82% had not prescribed it in the last year. Finally, 76% expressed a desire for additional information on this topic. Conclusions: Belgian GPs should evaluate the possibility of conducting UAT testing in their laboratories to enhance LD case management and improve their preparedness. Furthermore, initiatives should be implemented to improve communication between specialists and GPs and develop educational programs directed at Belgian GPs.

Antibiotic Strategies for Severe Community-Acquired Pneumonia

Despite advancements in health systems and intensive care unit (ICU) care, along with the introduction of novel antibiotics and microbiologic techniques, mortality rates in severe community-acquired pneumonia (sCAP) patients have not shown significant improvement. Delayed admission to the ICU is a major risk factor for higher mortality. Apart from choosing the appropriate site of care, prompt and appropriate antibiotic therapy significantly affects the prognosis of sCAP. Treatment regimens involving ceftaroline or ceftobiprole are currently considered the best options for managing patients with sCAP. Additionally, several other molecules, such as delafloxacin, lefamulin, and omadacycline, hold promise as therapeutic strategies for sCAP. This review aims to provide a comprehensive summary of the key challenges in managing adults with severe CAP, focusing on essential aspects related to antibiotic treatment and investigating potential strategies to enhance clinical outcomes in sCAP patients.

Levofloxacin-Induced Hepatotoxicity in Patients With Legionnaires' Disease: Implications and Management

Legionnaires' disease (LD), caused by the Legionella bacterium, primarily manifests as pneumonia and could result in a spectrum of clinical severity. As treatment necessitates the use of antibiotics, levofloxacin, a fluoroquinolone, is a commonly preferred option due to its broad-spectrum activity. However, the potential side effects of levofloxacin, including rare instances of hepatotoxicity, introduce a therapeutic challenge. This case report explores the association between levofloxacin and hepatotoxicity and its implications for treating LD.

Tenets of a holistic approach to drinking water-associated pathogen research, management, and communication

In recent years, drinking water-associated pathogens that can cause infections in immunocompromised or otherwise susceptible individuals (henceforth referred to as DWPI), sometimes referred to as opportunistic pathogens or opportunistic premise plumbing pathogens, have received considerable attention. DWPI research has largely been conducted by experts focusing on specific microorganisms or within silos of expertise. The resulting mitigation approaches optimized for a single microorganism may have unintended consequences and trade-offs for other DWPI or other interests (e.g., energy costs and conservation). For example, the ecological and epidemiological issues characteristic of Legionella pneumophila diverge from those relevant for Mycobacterium avium and other nontuberculous mycobacteria. Recent advances in understanding DWPI as part of a complex microbial ecosystem inhabiting drinking water systems continues to reveal additional challenges: namely, how can all microorganisms of concern be managed simultaneously? In order to protect public health, we must take a more holistic approach in all aspects of the field, including basic research, monitoring methods, risk-based mitigation techniques, and policy. A holistic approach will (i) target multiple microorganisms simultaneously, (ii) involve experts across several disciplines, and (iii) communicate results across disciplines and more broadly, proactively addressing source water-to-customer system management.

[Management of Adult Community-Acquired Pneumonia and Prevention - Update 2021 - Guideline of the German Respiratory Society (DGP), the Paul-Ehrlich-Society for Chemotherapy (PEG), the German Society for Infectious Diseases (DGI), the German Society of Medical Intensive Care and Emergency Medicine (DGIIN), the German Viological Society (DGV), the Competence Network CAPNETZ, the German College of General Practitioneers and Family Physicians (DEGAM), the German Society for Geriatric Medicine (DGG), the German Palliative Society (DGP), the Austrian Society of Pneumology Society (ÖGP), the Austrian Society for Infectious and Tropical Diseases (ÖGIT), the Swiss Respiratory Society (SGP) and the Swiss Society for Infectious Diseases Society (SSI)]

The present guideline provides a new and updated concept of the management of adult patients with community-acquired pneumonia. It replaces the previous guideline dating from 2016.The guideline was worked out and agreed on following the standards of methodology of a S3-guideline. This includes a systematic literature search and grading, a structured discussion of recommendations supported by the literature as well as the declaration and assessment of potential conflicts of interests.The guideline has a focus on specific clinical circumstances, an update on severity assessment, and includes recommendations for an individualized selection of antimicrobial treatment.The recommendations aim at the same time at a structured assessment of risk for adverse outcome as well as an early determination of treatment goals in order to reduce mortality in patients with curative treatment goal and to provide palliation for patients with treatment restrictions.

Updates on community acquired pneumonia management in the ICU

While the world is grappling with the consequences of a global pandemic related to SARS-CoV-2 causing severe pneumonia, available evidence points to bacterial infection with Streptococcus pneumoniae as the most common cause of severe community acquired pneumonia (SCAP). Rapid diagnostics and molecular testing have improved the identification of co-existent pathogens. However, mortality in patients admitted to ICU remains staggeringly high.

The American Thoracic Society and Infectious Diseases Society of America have updated CAP guidelines to help streamline disease management. The common theme is use of timely, appropriate and adequate antibiotic coverage to decrease mortality and avoid drug resistance. Novel antibiotics have been studied for CAP and extend the choice of therapy, particularly for those who are intolerant of, or not responding to standard treatment, including those who harbor drug resistant pathogens. In this review, we focus on the risk factors, microbiology, site of care decisions and treatment of patients with SCAP.

Antibiotic Resistance of Legionella pneumophila in Clinical and Water Isolates-A Systematic Review

The current systematic review investigates the antibiotic susceptibility pattern of Legionella pneumophila isolates from the 1980s to the present day, deriving data from clinical and/or water samples from studies carried out all over the world. Eighty-nine papers meeting the inclusion criteria, i.e., “Legionella pneumophila” and “resistance to antibiotics”, were evaluated according to pre-defined validity criteria. Sixty articles referred to clinical isolates, and 18 articles reported water-related L. pneumophila isolates, while 11 articles included both clinical and water isolates. Several methods have been proposed as suitable for the determination of MICs, such as the E-test, broth and agar dilution, and disk diffusion methods, in vivo and in vitro, using various media. The E-test method proposed by the European Society of Clinical Microbiology and Infectious Diseases (EUCAST) seems to be the second most frequently used method overall, but it is the preferred method in the most recent publications (2000–2019) for the interpretation criteria. Erythromycin has been proved to be the preference for resistance testing over the years. However, in the last 19 years, the antibiotics ciprofloxacin (CIP), erythromycin (ERM), levofloxacin (LEV) and azithromycin (AZM) were the ones that saw an increase in their use. A decrease in the sensitivity to antibiotics was identified in approximately half of the reviewed articles.

Community acquired pneumonia by Legionella pneumophila: Study of 136 cases

OBJECTIVE

Most of the data on Legionella pneumonia in our country come from the Mediterranean area, and there are few studies from the Northwest area. This study tries to assess the situation of this infection in this area.

METHOD

Retrospective study of all patients with positive Legionella antigenuria treated at the University Hospital Lucus Augusti in Lugo (Spain) from 2001, the year in which this test was introduced in our centre, until 2015. We analysed epidemiological data, risk factors, clinical, radiological and biochemical findings, and clinical outcome.

RESULTS

The sampled included 136 patients. When comparing the first five years of the study with the last five, the incidence increased from 10.9 to 64.5 cases/1,000,000; the number of antigenuria requests increased 3.4 times, and compared to other pneumonia aetiologies Legionella increased from 0.9% to 15%. The mean age was 64.1years and 84.6% were males; 74.3% had comorbidities. Males were significantly younger (62.7±16.6 vs 71.9±17.3) and consumed more alcohol (26.1% vs 0%) and tobacco (67.8% vs 14.3%). Diagnosis was established within the first 72hours in 88.9% of cases and most received levofloxacin (95.6%). Hospitalisation was needed in 85% of cases, 11.7% in ICU and 4.4% died.

CONCLUSIONS

After the introduction of antigenuria there was an increase in the incidence of Legionella pneumonia recorded in our health area. Its rate in recent years has been one of the highest in our country. Despite the fact that the patients had advanced age and comorbidities, mortality was low.

In vitro activity of various antibiotics against clinical strains of Legionella species isolated in Japan

The activities of various antibiotics against 58 clinical isolates of Legionella species were evaluated using two methods, extracellular activity (minimum inhibitory concentration [MIC]) and intracellular activity. Susceptibility testing was performed using BSYEα agar. The minimum extracellular concentration inhibiting intracellular multiplication (MIEC) was determined using a human monocyte-derived cell line, THP-1. The most potent drugs in terms of MICs against clinical isolates were levofloxacin, garenoxacin, and rifampicin with MIC₉₀ values of 0.015 μg/ml. The activities of ciprofloxacin, pazufloxacin, moxifloxacin, clarithromycin, and azithromycin were slightly higher than those of levofloxacin, garenoxacin, and rifampicin with an MIC₉₀ of 0.03-0.06 μg/ml. Minocycline showed the highest activity, with an MIC₉₀ of 1 μg/ml. No resistance against the antibiotics tested was detected. No difference was detected in the MIC distributions of the antibiotics tested between L. pneumophila serogroup 1 and L. pneumophila non-serogroup 1. The MIECs of ciprofloxacin, pazufloxacin, levofloxacin, moxifloxacin, garenoxacin, clarithromycin, and azithromycin were almost the same as their MICs, with MIEC₉₀ values of 0.015-0.06 μg/ml, although the MIEC of minocycline was relatively lower and that of rifampicin was higher than their respective MICs. No difference was detected in the MIEC distributions of the antibiotics tested between L. pneumophila serogroup 1 and L. pneumophila non-serogroup 1. The ratios of MIEC:MIC for rifampicin (8) and pazufloxacin (2) were higher than those for levofloxacin (1), ciprofloxacin (1), moxifloxacin (1), garenoxacin (1), clarithromycin (1), and azithromycin (1). Our study showed that quinolones and macrolides had potent antimicrobial activity against both extracellular and intracellular Legionella species. The present data suggested the possible efficacy of these drugs in treatment of Legionella infections.

Legionella pneumonia in the Niagara Region, Ontario, Canada: a case series

BACKGROUND

Legionella pneumophila, a major cause of Legionnaires' disease, accounts for 2-15 % of all community-acquired pneumonia requiring hospitalization and up to 30 % of community-acquired pneumonia requiring intensive care unit admission. Early initiation of appropriate antimicrobial therapy is a crucial step in the prevention of morbidity and mortality. However, recognition of Legionnaires' disease continues to be challenging because of its nonspecific clinical features. We sought to describe hospitalized community-acquired Legionnaires' disease to increase awareness of this important and potentially lethal disease.

METHODS

A retrospective multicenter observational study was conducted with all patients with confirmed Legionnaires' disease in the Niagara Region of the Province of Ontario, Canada, from June to December 2013.

RESULTS

From June to December 2013, there were 14 hospitalized cases of Legionnaires' disease in the Niagara Region. Of these, 86 % (12 patients) had at least one comorbidity and 71 % (10 patients) were cigarette smokers. In our cohort, Legionnaires' disease was diagnosed with a combination of a urinary Legionella antigen test and a Legionella real-time polymerase chain reaction assay. Delay in effective antimicrobial therapy in the treatment of Legionella infection led to clinical deterioration. The majority of patients had met systemic inflammatory response syndrome criteria with fever >38 °C (71 %), heart rate >90 beats per minute (71 %), and respiratory rate >20 breaths per minute (86 %). Eleven patients (79 %) required admission to the intensive care unit or step-down unit, and nine patients (64 %) required intubation. Clinical improvement after initiation of antimicrobials was protracted.

CONCLUSIONS

Legionnaires' disease should be considered during the late spring and summer months in patients with a history of tobacco use and various comorbidities. Clinically, patients presented with severe, nonspecific, multisystem disease characterized by shortness of breath, abnormal vital signs, and laboratory derangements including hyponatremia, elevated creatine kinase, and evidence of organ dysfunction. In addition, antimicrobial therapy with newer macrolides or respiratory fluoroquinolones should be initiated for severe community-acquired pneumonia requiring intensive care unit admission, prior to laboratory confirmation of diagnosis, especially when a clinical suspicion of Legionella infection exists.

Precision medicine for the treatment of severe pneumonia in intensive care

Despite advances in its management, community-acquired pneumonia (CAP) remains the most important cause of sepsis-related mortality and the reason for many ICU admissions. Severity assessment is the cornerstone of CAP patient management and the attempts to ensure the best site of care and therapy. Survival depends on a combination of host factors (genetic, age, comorbidities, defenses), pathogens (virulence, serotypes) and drugs. To reduce CAP mortality, early adequate antibiotic therapy is fundamental. The use of combination therapy with a macrolide seems to improve the clinical outcome in the subset of patients with high inflammation due to immunomodulation. Guidelines on antibiotic therapy have been associated with beneficial effects, and studies of newer adjunctive drugs have produced promising results. This paper discusses the current state of knowledge regarding of precision medicine and the treatment of severe CAP patients.

Legionnaires' disease

Since first identified in early 1977, bacteria of the genus Legionella are recognised as a common cause of community-acquired pneumonia and a rare cause of hospital-acquired pneumonia. Legionella bacteria multisystem manifestations mainly affect susceptible patients as a result of age, underlying debilitating conditions, or immunosuppression. Water is the major natural reservoir for Legionella, and the pathogen is found in many different natural and artificial aquatic environments such as cooling towers or water systems in buildings, including hospitals. The term given to the severe pneumonia and systemic infection caused by Legionella bacteria is Legionnaires' disease. Over time, the prevalence of legionellosis or Legionnaires' disease has risen, which might indicate a greater awareness and reporting of the disease. Advances in microbiology have led to a better understanding of the ecological niches and pathogenesis of the condition. Legionnaires' disease is not always suspected because of its non-specific symptoms, and the diagnostic tests routinely available do not offer the desired sensitivity. However, effective antibiotics are available. Disease notification systems provide the basis for initiating investigations and limiting the scale and recurrence of outbreaks. This report reviews our current understanding of this disease.

Multiplex real-time PCR assay for Legionella species

Legionella pneumophila serogroup 1 (sg1) accounts for the majority of infections in humans, but other Legionella species are also associated with human disease. In this study, a new SYBR Green I-based multiplex real-time PCR assay in a single reaction was developed to allow the rapid detection and differentiation of Legionella species by targeting specific gene sequences. Candidate target genes were selected, and primer sets were designed by referring to comparative genomic hybridization data of Legionella species. The Legionella species-specific groES primer set successfully detected all 30 Legionella strains tested. The xcpX and rfbA primers specifically detected L. pneumophila sg1-15 and L. pneumophila sg1, respectively. In addition, this assay was validated by testing clinical samples and isolates. In conclusion, this novel multiplex real-time PCR assay might be a useful diagnostic tool for the rapid detection and differentiation of Legionella species in both clinical and epidemiological studies.

The bacterial pneumonias: a new treatment paradigm

Pneumonia is a common disease that carries a high mortality. Traditionally, pneumonia has been classified and treated according to the setting where the pneumonia develops, namely community-acquired pneumonia, health-care-associated pneumonia, and hospital-acquired pneumonia. This classification was based on the risk of a patient being infected with a hospital-acquired drug-resistant pathogen. A new treatment paradigm has been proposed based on the risk of the patient being infected with a community-acquired drug-resistant pathogen. The risk factors for infection with a community-acquired drug-resistant pathogen include (1) hospitalization for > 2 days during the previous 90 days, (2) antibiotic use during the previous 90 days, (3) nonambulatory status, (4) tube feeds, (5) immunocompromised status, (6) use of acid-suppressive therapy, (7) chronic hemodialysis during the preceding 30 days, (8) positive methicillin-resistant Staphylococcus aureus history within the previous 90 days, and (9) present hospitalization > 2 days. This article reviews this new treatment paradigm and other issues relevant to the diagnosis and management of pneumonia based on information from MEDLINE, EMBASE, and the Cochrane Register of Controlled Trials.

[A case of Legionnaires' infection with meningeal irritation and abnormal cerebrospinal fluid]

A 60-year-old man was admitted to our hospital because of fever and mental status change. Neurological examination showed meningeal irritation and frontal sign. Cerebrospinal fluid (CSF) examination showed mild pleocytosis and elevated protein. Laboratory findings showed hyponatremia, elevated liver enzymes and creatine phosphokinase, and positive Legionella pneumophila antigen in urine. The chest computed tomographic scans showed consolidation in the left lower lobe lung. We diagnosed Legionnaires' pneumonia and started treatment with levofloxacin. Legionella pneumophila was isolated from culture of the bronchoalveolar lavage fluid, but Legionella culture and polymerase chain reaction in CSF were negative. We hypothesize that Legionella pneumophila could produce nerological symptoms by immune-mediated mechanism associated with elevated IgG index. The neurologist should recognize the presence of the meningo-encephalitis associated with Legionnaires' pneumonia lacking remarkable pulmonary symptoms.

Current clinical management of Legionnaires’ disease

Legionella pneumophila is increasingly recognized as a cause of both sporadic and epidemic community-acquired pneumonia. Clinical manifestations of Legionnaires' disease are not specific and current diagnostic scores are of limited use. Urinary antigen detection is an effective test for rapid diagnosis of infection caused by L. pneumophila serogroup 1. Improved outcomes regarding the time to defervescence, development of complications and length of stay, have been recently observed for patients treated with levofloxacin monotherapy. Current case-fatality rates for hospitalized patients with community-acquired Legionella pneumonia are lower than those traditionally reported for this infection. Effective preventive strategies are needed.

Correlation of MIC value and disk inhibition zone diameters in clinical Legionella pneumophila serogroup 1 isolates

OBJECTIVES

Routine use of disk diffusion tests for detecting antibiotic resistance in Legionella pneumophila has not been described. The goal of this study was to determine the correlation of MIC values and inhibition zone diameter (MDcorr) in clinical L. pneumophila isolates.

METHODS

Inhibition zone diameter of 183 L. pneumophila clinical isolates were determined for ten antimicrobials. Disk diffusion results were correlated with MICs as determined earlier with E-tests.

RESULTS

Overall the correlation of MIC values and inhibition zone diameters (MDcorr) of the tested antimicrobials is good, and all antimicrobials showed a WT distribution. Of the tested fluoroquinolones levofloxacin showed the best MDcorr. All macrolides showed a wide MIC distribution and good MDcorr. The MDcorr for cefotaxim, doxycycline and tigecycline was good, while for rifampicin and moxifloxacin, they were not.

CONCLUSION

Overall good correlation between MIC value and disk inhibition zone were found for the fluoroquinolones, macrolides and cefotaxim.

Clinical use of anti-TNF therapy and increased risk of infections

Biologics such as antitumor necrosis factor (anti-TNF) drugs have emerged as important agents in the treatment of many chronic inflammatory diseases, especially in cases refractory to conventional treatment modalities. However, opportunistic infections have become a major safety concern in patients on anti-TNF therapy, and physicians who utilize these agents must understand the increased risks of infection. A literature review of the published data on the risk of bacterial, viral, fungal, and parasitic infections associated with anti-TNF therapy was performed and the clinical presentation, diagnostic tests, management, and prevention of opportunistic infections in patients receiving anti-TNF therapy were reviewed. Awareness of the therapeutic potential and associated adverse events is necessary for maximizing therapeutic benefits while minimizing adverse effects from anti-TNF treatments. Patients should be adequately vaccinated when possible and closely monitored for early signs of infection. When serious infections occur, withdrawal of anti-TNF therapy may be necessary until the infection has been identified and properly treated.

The effect of levofloxacin and moxifloxacin on cardiovascular functions of rats with streptozotocin-induced diabetes

Fluoroquinolone antibiotics cause rare, but clinically important, adverse events including hyperglycaemia and hypoglycaemia. The present study focuses on the possible effect of levofloxacin and moxifloxacin on the cardiovascular functions of rats with type I diabetes. Both antibiotics caused bradycardia. Levofloxacin but not moxifloxacin caused hypoglycaemia in diabetic rats and an increase in amplitude of the ST segment revealed by electrocardiogram (ECG) analysis of isolated hearts. In pressurized mesenteric arteries, levofloxacin did not affect the endothelium-derived hyperpolarising factor (EDHF) pathway or its main components, the small-conductance Ca(2+) activated potassium (SK(Ca)) and intermediate-conductance Ca(2+) activated potassium (IK(Ca)) channels. In moxifloxacin-treated rats, an increase in the EDHF response was observed, which was largely attributed to SK(Ca)-activation. In conclusion, levofloxacin and moxifloxacin use appeared to vary but with no evidence of impairment of the cardiovascular function. However, it is still possible that these antibiotics may produce different effects if there are co-morbidities and therefore their use must be with care.

Community-acquired Legionella Pneumonia in the intensive care unit: Impact on survival of combined antibiotic therapy

OBJECTIVES

To compare intensive care unit (ICU) mortality in patients with severe community-acquired pneumonia (SCAP) caused by Legionella pneumophila receiving combined therapy or monotherapy.

METHODS

A prospective multicenter study was made, including all patients with sporadic, community-acquired Legionnaires' disease (LD) admitted to the ICU. Admission data and information on the course of the disease were recorded. Antibiotic prescriptions were left to the discretion of the attending physician and were not standardized.

RESULTS

Twenty-five cases of SCAP due to L. pneumophila were included, and 7 patients (28%) out of 25 died after a median of 7 days of mechanical ventilation. Fifteen patients (60%) presented shock. Levofloxacin and clarithromycin were the antibiotics most commonly used in monotherapy, while the most frequent combination was rifampicin plus clarithromycin. Patients subjected to combination therapy presented a lower mortality rate versus patients subjected to monotherapy (odds ratio for death [OR] 0.15; 95%CI 0.02-1.04; p=0.08). In patients with shock, this association was stronger and proved statistically significant (OR for death 0.06; 95%CI 0.004-0.86; p=0.04).

CONCLUSIONS

Combined antibiotic therapy decreases mortality in patients with SCAP and shock caused by L. pneumophila.

Severe sepsis in community-acquired pneumonia--early recognition and treatment

Despite remarkable advances in its management, community-acquired pneumonia (CAP) remains an important cause of morbidity and mortality leading to significant consumption of health, social and economic resources. The assessment of CAP severity is a cornerstone in its management, facilitating selection of the most appropriate site of care and empirical antibiotic therapy. Several clinical scoring systems based on 30-day mortality have been developed to identify those patients with the highest risk of death. Although well validated in appropriate patient groups, each system has its own limitations and each exhibits different sensitivity and specificity values. These problems have increased interest in the use of biomarkers to predict CAP severity. Although so far no ideal solution has been identified, recent advances in bacterial genomic load quantification have made this tool very attractive. Early antibiotic therapy is essential to the reduction of CAP mortality and the selection of antibiotic treatment according to clinical guidelines is also associated with an improved outcome. In addition, the addition of a macrolide to standard empirical therapy seems to improve outcome in severe CAP although the mechanism of this is unclear. Finally, the role of adjuvant therapy has not yet been satisfactorily established. In this review we will present our opinion on current best practice in the assessment of severity and treatment of severe CAP.

Guidelines for the management of adult lower respiratory tract infections--summary

This document is an update of Guidelines published in 2005 and now includes scientific publications through to May 2010. It provides evidence-based recommendations for the most common management questions occurring in routine clinical practice in the management of adult patients with LRTI. Topics include management outside hospital, management inside hospital (including community-acquired pneumonia (CAP), acute exacerbations of COPD (AECOPD), acute exacerbations of bronchiectasis) and prevention. The target audience for the Guideline is thus all those whose routine practice includes the management of adult LRTI.

Guidelines for the management of adult lower respiratory tract infections--full version

This document is an update of Guidelines published in 2005 and now includes scientific publications through to May 2010. It provides evidence-based recommendations for the most common management questions occurring in routine clinical practice in the management of adult patients with LRTI. Topics include management outside hospital, management inside hospital (including community-acquired pneumonia (CAP), acute exacerbations of COPD (AECOPD), acute exacerbations of bronchiectasis) and prevention. Background sections and graded evidence tables are also included. The target audience for the Guideline is thus all those whose routine practice includes the management of adult LRTI.

Community-acquired pneumonia due to Legionella pneumophila, the utility of PCR, and a review of the antibiotics used

Introduction

There are at least 40 types of Legionella bacteria, half of which are capable of producing disease in humans. The Legionella pneumophila bacterium, the root cause of Legionnaires’ disease, causes 90% of legionellosis cases.

Case presentation

We describe the case of a 60-year-old woman with a history of diabetes mellitus and arterial hypertension who was admitted to our hospital with fever and symptoms of respiratory infection, diarrhea, and acute renal failure. We used real-time polymerase chain reaction (PCR) to detect L. pneumophila DNA in peripheral blood and serum samples and urine antigen from a patient with pneumonia. Legionella DNA was detected in all two sample species when first collected.

Conclusion

Since Legionella is a cause of 2% to 15% of all community-acquired pneumonias that require hospitalization, legionellosis should be taken into account in an atypical pulmonary infection and not be forgotten. Moreover, real-time PCR should be considered a useful diagnostic method.

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.

A Review of Levofloxacin for the Treatment of Bacterial Infections

Completing its initial phases of drug development in the mid 1990s as the one of the first fluoroquinolones that could be used with confidence to treat respiratory tract infections, levofloxacin went on to become one of the most widely prescribed antibiotics in the world. Available in both oral (po) and intravenous (IV) formulations and with characteristics of over 90% bioavailability, distribution into both extracellular and intracellular pulmonary compartments, highly predictable pharmacokinetics with over 90% of the drug being excreted unchanged in urine, and reliable activity against a broad spectrum of clinically important pathogens, levofloxacin has been used successfully to treat patients with a variety of serious infectious diseases as well as common infections most often treated outside of the hospital setting. Results of clinical trials involving patients with respiratory tract, urinary tract, and skin infections have consistently shown rates of clinical success and bacteriological eradication that were comparable to other widely used broad-spectrum agents. Regimens of levofloxacin, initially involving total daily doses of 250 mg to 500 mg, but more recently regimens involving 750 mg doses, have been shown to be safe and effective. Nearly a decade and a half of clinical experience has defined a safety and tolerability profile that permits data-driven assessment of the risks and benefits of using levofloxacin. As resistance to currently available fluoroquinolones has emerged, the clinical value of levofloxacin deserves continued evaluation. However, consistently high rates of susceptibility of clinically important bacteria, especially among those bacteria that commonly cause respiratory tract infections, such as Streptococcus pneumoniae and Haemophilus influenzae, suggest that this agent will continue to be a widely used well past the 20-year anniversary of its introduction into the antibacterial armamentarium.

Legionella pneumonia in cancer patients

Legionella is an important cause of nosocomial and community-acquired pneumonia in both immunocompetent and immunosuppressed patients worldwide; however, the clinical course and optimal antibiotic therapy of Legionella pneumonia (LP) in patients with cancer is uncertain. We studied retrospectively the risk factors, clinical manifestations, and outcome of 49 cancer patients with a positive Legionella culture or direct fluorescent antibody (DFA) over a 13-year period (1991-2003). The majority of patients (82%) had an underlying hematologic malignancy, and 37% were bone marrow transplant recipients; 80% of the patients had active malignancy. Lymphopenia (47%), use of systemic corticosteroids (41%), and chemotherapy (63%) were the most common underlying conditions. The laboratory diagnosis was established by positive Legionella culture (n = 8, 16%), DFA (n = 29, 59%), or both (n = 12, 25%). In 4 patients (8%), a positive DFA was deemed to represent false-positive results. There was no temporal or geographic clustering of cases. The majority of the cases had multilobar (61%) or bilateral (55%) pulmonary involvement. The mean time to response to therapy was 8 days; 18 patients (37%) developed complications requiring prolonged duration of treatment (mean, 25 d). The case-fatality rate was 31%. Two patients had relapse of LP despite appropriate therapy. Improved outcome, especially in those with severe pneumonia, seemed to correlate with the use of a combination of antibiotics. LP is an uncommon infection in our patient population but is associated with significant morbidity and mortality. Treatment of LP in cancer patients may require a prolonged course with a regimen that includes a newer macrolide or quinolone.

Legionella spp. and Legionnaires' disease

Infection with Legionella spp. is an important cause of community- and hospital-acquired pneumonia, occurring both sporadically and in outbreaks. Infection with Legionella spp. ranks among the three most common causes of severe pneumonia in the community setting, and is isolated in 1-40% of cases of hospital-acquired pneumonia. There are no clinical features unique to Legionnaires' disease. Macrolides and fluoroquinolones are the most widely used drugs in treatment. The availability of a good diagnostic repertoire, suitable for accurately diagnosing LD, constitutes the basis for the early recognition and treatment of the individual patient as well as for effective measures for prevention and control. This review summarizes the available information regarding the microbiology, clinical presentation, diagnosis and treatment of LD, with an emphasis on the laboratory diagnosis of infection with Legionella spp.

Intrapulmonary pharmacodynamics of high-dose levofloxacin in subjects with chronic bronchitis or chronic obstructive pulmonary disease

The objective of this study was to determine the plasma and intrapulmonary pharmacokinetic parameters of intravenously administered levofloxacin in subjects with stable chronic lung disease. Three doses of 1000 mg levofloxacin were administered once daily to 16 adult subjects divided into four groups of 4 subjects each. Standardised bronchoscopy and timed bronchoalveolar lavage (BAL) were performed at 4 h, 8 h, 12 h and 24 h following administration of the last dose. Blood was obtained for drug assay prior to drug administration, at the end of the last infusion (maximum concentration (Cmax)) and at the time of BAL. Levofloxacin was measured using a high-performance liquid chromatographic tandem mass spectrometric (HPLC/MS/MS) technique. Plasma, epithelial lining fluid (ELF) and alveolar cell (AC) pharmacokinetics were derived using non-compartmental methods. Cmax/MIC(90) and area under the concentration-time curve for 0-24 h after the last dose (AUC(0-24 h)/MIC(90) ratios were calculated for respiratory pathogens with minimum inhibitory concentrations for 90% of the organisms (MIC(90)) of 0.03-2 microg/mL. The Cmax (mean+/-standard deviation), AUC(0-24h) and half-life were, respectively, 9.2+/-2.7 microg/mL, 130 microg h/mL and 8.7 h for plasma, 22.8+/-12.9 microg/mL, 260 microg h/mL and 7.0 h for ELF and 76.3+/-28.7 microg/mL, 1492 microg h/mL and 49.5 h for ACs. Levofloxacin concentrations were quantitatively greater in ACs than in ELF or plasma at all time points, however only the differences between AC concentration and ELF or plasma concentrations in the 4-h and 8-h time groups were statistically significant. Cmax/MIC(90) and AUC/MIC(90) ratios in ELF were, respectively, 11.4 and 130 for Mycoplasma pneumoniae, 22.8 and 260 for Streptococcus pneumoniae, 91.2 and 1040 for Chlamydia pneumoniae and 760 and 8667 for Haemophilus influenzae. In ACs the ratios were 38.2 and 746 for M. pneumoniae, 76.3 and 1492 for S. pneumoniae, 305 and 5968 for C. pneumoniae and 2543 and 49 733 for H. influenzae. In conclusion, Cmax/MIC(90) and AUC/MIC(90) ratios provide a pharmacokinetic rationale for once-daily administration of a 1000 mg dose of levofloxacin and are favourable for the treatment of respiratory infection in patients with chronic lung disease.

Outbreak of Legionnaires' disease in immunosuppressed patients at a cancer centre: usefulness of universal urine antigen testing and early levofloxacin therapy

This report describes an outbreak of Legionnaires' disease in severely immunosuppressed patients hospitalised at a cancer centre. Universal urine antigen testing and early levofloxacin therapy appeared to lower case fatality rates in comparison with previous reports concerning this high-risk population. This diagnostic and therapeutic strategy should be considered when facing a nosocomial outbreak of Legionnaires' disease in immunosuppressed hosts.

Activity of telithromycin and comparators against isolates of Legionella pneumophila collected from patients with community-acquired respiratory tract infections: PROTEKT Years 1-5

The in-vitro activity of telithromycin and comparator antibacterial agents was determined against clinical isolates of Legionella pneumophila collected in the PROTEKT surveillance study. In total, 133 isolates were collected between 1999 and 2004 from 13 countries (Australia, Belgium, Czech Republic, France, Germany, Hungary, Ireland, Italy, Japan, Portugal, Spain, Sweden and the USA). MICs were determined by broth microdilution. Telithromycin maintained activity between Year 1 (MIC(90) 0.015 mg/L) and Year 5 (MIC(90) 0.03 mg/L), as did the comparator antibacterial agents. Telithromycin appears to be a candidate for coverage of legionellosis in the empirical treatment of community-acquired respiratory tract infection.

Légionellose

Legionnaires disease, more formally known as legionellosis, is a relatively common form of severe pneumonia caused by Legionella, a genus of waterborne bacteria. Legionellosis is acquired by inhalation of legionellae from contaminated environmental sources. Legionella pneumophila serogroup 1 is responsible for more than 80% of cases in most countries. More than 1500 cases were reported in France in 2005. Initial diagnosis is based on tests for urinary antigens. The mortality rate for legionellosis depends on the promptness of appropriate antibiotic therapy. Macrolides (erythromycin or intravenous azithromycin, which is preferred to erythromycin for its better pharmacodynamic properties) and fluoroquinolones (levofloxacin) are the antibiotics of choice for severe legionellosis.