Prospective evaluation of a two-week course of intravenous antibiotics in intravenous drug addicts with infective endocarditis. Grupo de Estudio de Enfermedades Infecciosas de la Provincia de Cádiz

Case report: isolated pulmonary valve endocarditis in a 39-year-old patient with intravenous drug abuse

Background 

Isolated pulmonary valve endocarditis is a very rare form of right-sided infective endocarditis. Due to the anatomy, in most cases, just the tricuspid valve is involved. Diagnosis can be challenging because of non-specific symptoms (fever, dyspnoea, haemoptysis, and pleuritic chest pain) and difficulty of detection by echocardiography. Risk factors include intravenous drug abuse, congenital heart disorders, alcohol abuse, male sex and central venous catheters, or pacemaker leads.

Case summary 

A 39-year-old homeless male patient, who was a current intravenous drug user, presented with fever, dyspnoea, and haemoptysis. The chest X-ray showed bilateral infiltrates. Empiric antibiotic treatment was initiated. Blood cultures showed the presence of Streptococcus dysgalactiae. Atypical causes of pneumonia were excluded. Systemic embolism was suspected, and a computed tomography scan of brain, thorax, and abdomen was performed. Multiple septic embolic lesions were detected in both lungs. Echocardiography revealed an isolated pulmonary valve endocarditis. Penicillin G and gentamycin were administered intravenously for a duration of 6 and 2 weeks, respectively. The patient was discharged in stable condition but did not return for outpatient clinical appointments.

Discussion 

To detect rare causes of right-sided infective endocarditis, repeated echocardiograms with special focus on the pulmonary valve may be required. Usually, antibiotic treatment alone leads to recovery. In special situations (heart failure, septic shock, or large vegetation size) surgery is required. Due to the high risk of postoperative complications, surgery in intravenous drug users should be avoided if possible.

Infective Endocarditis as a Complication of Intravenous Drug Use in Pregnancy: A Retrospective Case Series and Literature Review

Objective  An increase in opioid use disorder and subsequent intravenous drug use has led to an increase in sequalae that may complicate pregnancy, such as infective endocarditis. Infective endocarditis has the potential for significant maternal and neonatal morbidity and mortality. We sought to examine the management considerations and clinical implications of intravenous drug use-related infective endocarditis in pregnancy from our center's experience. Study Design  Retrospective study of management of pregnancies complicated by infective endocarditis as a result of active intravenous drug use at an academic tertiary care hospital from January 2012 through December 2019. Results  Twelve women with active intravenous drug use histories were identified as having clinical and echocardiographic features consistent with infective endocarditis. Six women were discharged against medical advice and did not complete the full course of recommended antibiotic regimen. Eight women were started or continued on opioid agonist therapy during their hospitalization. Four neonates required neonatal intensive care unit admission for pharmacologic treatment for neonatal abstinence syndrome. Conclusion  Management of intravenous drug use-associated infective endocarditis in pregnancy involves more than treating the acute condition. In pregnant women with opioid use disorder and infective endocarditis, addiction and chronic psychosocial conditions need to be addressed to optimize care.

Optimizing outcomes in infective endocarditis: A comprehensive literature review

BACKGROUND

Despite being rare, infective endocarditis (IE) is a life-threatening disease with poor prognosis. New diagnostic and therapeutic strategies are emerging; however, predisposing factors and microbiology of the disease are also changing with time. Because of this, there has been a lack of reduction in the disease's incidence and new challenges for clinicians have arisen such as an increasingly aging population and growing antimicrobial resistance.

AIMS

In this paper, we aim to provide an overview of the changing trends in IE, current diagnosis, and management strategies, as well as the emerging role of the infective endocarditis teams in the care of patients with this disease.

MATERIALS & METHODS

A comprehensive electronic search was done utilizing PubMed, Ovid, SCOPUS, Embase and google scholar. The search terms included 'Endocarditis', 'IE', 'Infection', 'Vegetation', 'Duke criteria', 'native valve infection', 'prosthetic valve', 'valve infection', 'endocarditis outcome' and 'endocarditis bacteriology'. The references of the identified articles were then searched for any potential articles that can be included. The inclusion criteria were any article that discussed the evidence behind incidence and management of IE including the role of endocarditis team. The exclusion criteria were case reports, expert opinion, and editorials.

RESULTS

All the relevant findings are summarized in specified tables and within appropriate sections.

DISCUSSION

It is vital to determine the current trends in the epidemiology and microbiology of the condition so that the diagnostic threshold can be adapted, to identify new at-risk groups and achieve an accelerated evaluation strategy that allows for earlier diagnosis and treatment.

CONCLUSION

Management of IE can benefit from the input of different specialties, such as cardiology, cardiothoracic surgery, infectious disease, and microbiology. Therefore, adopting a multidisciplinary approach towards treatment is crucial to reduce morbidity and mortality from preventable complications of this pathology.

Clinical Practice Update on Infectious Endocarditis

Infectious endocarditis is a highly morbid disease with approximately 43,000 cases per year in the United States. The modified Duke Criteria have poor sensitivity; however, advances in diagnostic imaging provide new tools for clinicians to make what can be an elusive diagnosis. There are a number of risk stratification calculators that can help guide providers in medical and surgical management. Patients who inject drugs pose unique challenges for the health care system as their addiction, which is often untreated, can lead to recurrent infections after valve replacement. There is a need to increase access to medication-assisted treatment for opioid use disorders in this population. Recent studies suggest that oral and depo antibiotics may be viable alternatives to conventional intravenous therapy. Additionally, shorter courses of antibiotic therapy are potentially equally efficacious in patients who are surgically managed. Given the complexities involved with their care, patients with endocarditis are best managed by multidisciplinary teams.

Medical complications of opioid use disorder in pregnancy

Women with opioid use disorder are at increased risk of other medical complications of pregnancy. Providing care for such complex patients requires the ability to 1) acknowledge addiction as a chronic disease, 2) incorporate the altered physiology of pregnancy, and 3) devise a treatment plan that can effectively manage acute conditions. A basic tenet of care is rooted in experience, rather than evidence, but includes stabilization of opiate use disorder (OUD) as a primary goal of management of other medical complications of pregnancy. Proceeding with treatment for other medical conditions will be suboptimal without stabilization of the underlying chronic disease process. This chapter outlines some associated medical complications of OUD both in general and some of which are unique to pregnancy: infectious diseases, soft tissue infections, endocarditis, cholestasis of pregnancy, and overdose.

Right-Sided Infective Endocarditis and Pulmonary Infiltrates: An Update

Sixty years after its initial description, right-sided infective endocarditis (RSIE) still poses a challenge to all medical practitioners. Epidemiological data reveal a rising incidence attributable to the global surge in the number of intravenous drug users and the increased use of central vascular catheters and implantable cardiac devices. RSIE differs from left-sided infective endocarditis in more than just the location of the involved cardiac valve. They have different clinical presentations, diagnostic findings, and prognoses; hence, they require different management strategies. Cardiac murmurs and systemic emboli are usually absent in RSIE, whereas pulmonary embolism and its related complications dominate the clinical picture. Diagnostic delay of RSIE is secondary to the similarity in its initial presentation to other entities. Complications may ensue as a result of this delay. Diagnosis can be initially confirmed by using transthoracic echocardiography, except in patients with implanted cardioverter defibrillator, where a transesophageal echocardiogram is necessary. Various factors may increase mortality and morbidity in RSIE such as tricuspid valve vegetation size, fungal etiology, and low CD4 cell count in HIV patients. Oxacillin and vancomycin had been the traditionally used agents for the treatment of methicillin-susceptible and methicillin-resistant Staphylococcus aureus, respectively. More recently, daptomycin has shown promising results, which has led to its Food and Drug Administration (FDA) approval for the treatment of S. aureus bacteremia and associated RSIE. The aim of this article is to provide a comprehensive update on RSIE including epidemiology, pathogenesis, microbiology, diagnosis, management, and prognosis.

Staphylococcus aureus infections: epidemiology, pathophysiology, clinical manifestations, and management

Staphylococcus aureus is a major human pathogen that causes a wide range of clinical infections. It is a leading cause of bacteremia and infective endocarditis as well as osteoarticular, skin and soft tissue, pleuropulmonary, and device-related infections. This review comprehensively covers the epidemiology, pathophysiology, clinical manifestations, and management of each of these clinical entities. The past 2 decades have witnessed two clear shifts in the epidemiology of S. aureus infections: first, a growing number of health care-associated infections, particularly seen in infective endocarditis and prosthetic device infections, and second, an epidemic of community-associated skin and soft tissue infections driven by strains with certain virulence factors and resistance to β-lactam antibiotics. In reviewing the literature to support management strategies for these clinical manifestations, we also highlight the paucity of high-quality evidence for many key clinical questions.

Bacteremia, Sepsis, and Infective Endocarditis Associated with Staphylococcus aureus

Bacteremia and infective endocarditis (IE) are important causes of morbidity and mortality associated with Staphylococcus aureus infections. Increasing exposure to healthcare, invasive procedures, and prosthetic implants has been associated with a rising incidence of S. aureus bacteremia (SAB) and IE since the late twentieth century. S. aureus is now the most common cause of bacteremia and IE in industrialized nations worldwide and is associated with excess mortality when compared to other pathogens. Central tenets of management include identification of complicated bacteremia, eradicating foci of infection, and, for many, prolonged antimicrobial therapy. Evolving multidrug resistance and limited therapeutic options highlight the many unanswered clinical questions and urgent need for further high-quality clinical research.

Native valve right sided infective endocarditis

Right-sided infective endocarditis (RSIE) accounts for 5-10% of all cases of infective endocarditis (IE), and is predominantly encountered in the injecting drug user (IDU) population, where HIV and HCV coinfections often coexist. Staphylococcus aureus is the most common pathogen. The pathogenesis of RSIE is still not well understood. RSIE usually presents as a persistent fever with respiratory symptoms whilst signs of systemic embolisation as seen in left-sided IE are notably absent. The prompt diagnosis of RSIE thus requires a high index of suspicion. Transthoracic echocardiography (TTE) can detect the majority of RSIE, whilst transoesophageal echocardiography (TOE) can increase sensitivity. Virulence of the causative organism and vegetation size are the major determinants of prognosis. Most cases of RSIE resolve with appropriate antibiotic administration.

Considerations of antibiotic therapy duration in community- and hospital-acquired bacterial infections

Despite the large number of suggestions available in the literature, the optimal duration of antibiotic treatment remains an individual decision mainly based on clinical criteria. Shorter but equally effective regimens would reduce the side effect rates, including both antibiotic resistance and drug expenses. Although several prospective, randomized trials and meta-analyses with the aim of comparing a standard duration with a shorter one for most bacterial infections have been published, to date most current recommendations carry little weight, as they are based on expert opinions or practical experience. This review will briefly touch upon the clinical evidence of short-course versus long-course antibiotic therapy for the most common community- and hospital-acquired bacterial infections.

Postpartum culture negative endocarditis: a case report and review of the current guidelines

Culture-negative endocarditis (CNE) presents physicians with diagnostic and treatment challenges. Postpartum endocarditis is rare and usually culture negative. Empirical antimicrobial regimes lead to the risk of aggressive treatment with potentially toxic drugs. This paper presents a case of postpartum CNE, discussing the issues of diagnosis and treatment. European and American guidelines for CNE are then reviewed and compared.

Strategies for reduction in duration of antibiotic use in hospitalized patients

There is a global crisis of antibiotic resistance in part because of the collateral damage of antibiotic use. Reduction in antibiotic consumption is clearly important to minimize this problem. Limiting treatment duration may be the most clinically palatable means of reducing antibiotic consumption. Antimicrobial stewardship programs play an important role in this process. Their effectiveness may be increased by drawing on evidence from randomized controlled trials regarding optimal antibiotic duration. However, in most clinical scenarios, the recommended duration of therapy in published guidelines is based on expert opinion. Biological markers, such as procalcitonin, have been shown to reduce antimicrobial consumption with no adverse outcome in 11 randomized controlled trials. Although procalcitonin may not be the perfect biomarker, the concept of procalcitonin-guided antibiotic discontinuation after clinical stabilization, in conjunction with antimicrobial stewardship programs, appears to be ready for introduction into clinical practice.

Clinical management of Staphylococcus aureus bacteraemia

Staphylococcus aureus bacteraemia is one of the most common serious bacterial infections worldwide. In the UK alone, around 12,500 cases each year are reported, with an associated mortality of about 30%, yet the evidence guiding optimum management is poor. To date, fewer than 1500 patients with S aureus bacteraemia have been recruited to 16 controlled trials of antimicrobial therapy. Consequently, clinical practice is driven by the results of observational studies and anecdote. Here, we propose and review ten unanswered clinical questions commonly posed by those managing S aureus bacteraemia. Our findings define the major areas of uncertainty in the management of S aureus bacteraemia and highlight just two key principles. First, all infective foci must be identified and removed as soon as possible. Second, long-term antimicrobial therapy is required for those with persistent bacteraemia or a deep, irremovable focus. Beyond this, the best drugs, dose, mode of delivery, and duration of therapy are uncertain, a situation compounded by emerging S aureus strains that are resistant to old and new antibiotics. We discuss the consequences on clinical practice, and how these findings define the agenda for future clinical research.

Complicated Community-Acquired Staphylococcus Endocarditis and Multiple Lung Abscesses: Case Report and Review of Literature

Background. Isolated tricuspid valve endocarditis in the absence of risk factors in the community setting is very rare and can be easily missed in patients with hitherto normal valves. Case Presentation. We present a case of a 49 year old gentleman who presented with generalized body aches, fever, and jaundice and was initial diagnosed as hepatitis. He subsequently developed recurrent episodes of panic attacks and shortness of breath and later multiple skin abscesses. Further investigations excluded pulmonary embolism but revealed multiple abscesses in the body including the lungs. Blood cultures and culture from abscesses grew S. aureus. An initial transthoracic echocardiogram was normal. A transesophageal echocardiogram subsequently confirmed endocarditis on a normal natural tricuspid valve and multiple lung abscesses. He was successfully treated with appropriate antibiotics. Conclusion. We discuss the pathogenesis of this patient's presentation highlight the need for assessment and proper evaluation of patients with unexplained bacteremia.

Endocarditis caused by Staphylococcus aureus: A reappraisal of the epidemiologic, clinical, and pathologic manifestations with analysis of factors determining outcome

Staphylococcus aureus is the leading cause of infectious endocarditis and its mortality has remained high despite better diagnostic and therapeutic procedures over time. We conducted a retrospective review of 133 cases of definite S. aureus endocarditis seen at a single tertiary care hospital over 22 years to assess changes in the epidemiology and incidence of the infection, manifestations, outcome, risk factors for mortality, and impact of cardiac surgery on prognosis.Patients were classified into 2 groups: 1) right-sided endocarditis (64 patients) and 2) left-sided endocarditis (69 patients). While the number of cases of left-sided endocarditis remained steady at 1-3 cases per 10,000 admissions, the incidence of right-sided endocarditis, after a peak in the early 1990s, declined to almost disappear in 2001. Among the cases of right-sided endocarditis, we found 2 subsets of patients with different clinical features and prognosis: the first subset comprised 53 intravenous drug abusers, and the second subset comprised 11 patients with catheter-associated S. aureus bacteremia and endocarditis. Fifty-one patients were human immunodeficiency virus (HIV)-positive drug abusers, most of whom (80.3%) had right-sided endocarditis. We did not find differences in mortality between HIV-positive and HIV-negative individuals; mortality seemed to depend more on the site of the heart involved than on HIV status.Among the cases of left-sided endocarditis, the mitral valve was more commonly involved than the aortic valve (61% vs. 30%). Overall, 74% of patients with left-sided endocarditis developed 1 or more cardiac or extracardiac complication. In comparison, only 23.4% of patients with right-sided endocarditis developed complications.Prosthetic valve endocarditis (PVE) was hospital-acquired more frequently than native valve endocarditis (NVE). Patients with PVE had a shorter duration of symptoms until diagnosis and presented with or developed cardiac murmurs less frequently than patients with NVE. Cardiac failure (49%), renal failure (43%) and central nervous system (CNS) events (35%) were frequently observed in patients with both PVE and NVE. Valve replacement was more frequently needed and more rapidly performed in patients with PVE than in their counterparts with NVE.The overall mortality of patients with right-sided endocarditis was 17%. While the mortality of right-sided endocarditis in injection drug users was 3.7%, the mortality of patients with right-sided endocarditis associated with infected intravenous catheters was 82% (odds ratio [OR], 0.01; 95% confidence interval [CI], 0.001-0.07). For left-sided endocarditis mortality was 38% and was not significantly different in patients with NVE or PVE (OR, 0.65; 95% CI, 0.23-1.87). CNS complications were associated with mortality in both NVE (OR, 6.55; 95% CI, 1.78-24.04) and PVE (OR, 32; 95% CI, 2.63-465.40). Development of 2 or 3 complications was associated with an increased risk of mortality (OR, 5.59; 95% CI, 1.08-28.80 and OR, 9.25; 95% CI, 1.36-62.72 for 2 vs. 1 complication and for 3 vs. 2 complications, respectively).Surgical treatment did not significantly influence mortality in cases of NVE, (OR, 3.19; 95% CI, 0.76-13.38) but significantly improved the prognosis of patients with PVE (OR, 69; 95% CI, 2.89-1647.18).S. aureus endocarditis is an aggressive, often fatal, infection. The results of the current study suggest that valve replacement will improve the outcome of infection, particularly in patients with PVE.

[Summary of the GEIPC-SEIMC and GTEI-SEMICYUC recommendations for the treatment of infections caused by gram positive cocci in critical patients]

OBJECTIVE

In recent years there has been an increase in infections caused by gram-positive cocci in critical patients, together with a rapid development of resistance to the antibiotics which are normally used to treat them. The objective is to prepare an antibiotic treatment guide for the most common infections caused by gram positive cocci in critical patients. This guide will help in the decision-making process regarding the care of such patients.

METHOD

Experts from two scientific societies worked together to prepare a consensus document. They were members of the Study Group on Infections in Critical Patients (GEIPC), which is part of the Spanish Society of Infectious Diseases and Clinical Microbiology (SEIMC), and the Infectious Diseases Working Group (GTEI), belonging to the Spanish Society of Intensive Care Medicine and Coronary Units (SEMICYUC). There was a systematic review of the literature published up to September 2006 regarding this type of infections and the antibiotic treatments marketed to that date. An evidence grading system was applied according to the strength of the recommendation (categories A, B or C) and the level of evidence (categories I, II or III). Recommendations were given if there was consensus among the experts from both societies.

RESULTS

The antibiotic regimens recommended for treating infections caused by gram-positive cocci were presented in the form of tables, showing the recommendation grade. Alternatives were given for allergic patients. The scientific basis supporting the aforementioned recommendations is explained within the text and the references upon which they are based are cited.

CONCLUSIONS

A summary of an evidence-based practical guide for the treatment of infections caused by gram-positive cocci in critical patients is presented.

[Staphylococcus aureus bacteremia and endocarditis]

The prevalence of Stapylococcus bacteriaemia is increasing worldwide, because of the increasing use of invasive procedures leading to nosocomial infections, but also of a changing way of life (increasing fashion for tattoos or piercing, use of intravenous drugs). Infective endocarditis develops in 10-30% of the cases of staphylococcus bacteriaemia. Staphylococcus aureus endocarditis must be suspected when it develops in the year following heart surgery or implantation of permanent devices. In drug users, it usually involves the tricuspid valve. According to the resistance of the germ to meticillin, antibiotic therapy uses a combination of intravenous penicillin or glycopeptide and an aminoside. Other antibiotics such as fosfomycin, rifampicin, fusidic acid, or clindamycin can be used when aminosides are contra-indicated. The role of newer antibiotic agents, such as daptomycin or linezolide, remains to be established.

Swedish guidelines for diagnosis and treatment of infective endocarditis

Swedish guidelines for diagnosis and treatment of infective endocarditis (IE) by consensus of experts are based on clinical experience and reports from the literature. Recommendations are evidence based. For diagnosis 3 blood cultures should be drawn; chest X-ray, electrocardiogram, and echocardiography preferably transoesophageal should be carried out. Blood cultures should be kept for 5 d and precede intravenous antibiotic therapy. In patients with native valves and suspicion of staphylococcal aetiology, cloxacillin and gentamicin should be given as empirical treatment. If non-staphylococcal etiology is most probable, penicillin G and gentamicin treatment should be started. In patients with prosthetic valves treatment with vancomycin, gentamicin and rifampicin is recommended. Patients with blood culture negative IE are recommended penicillin G (changed to cefuroxime in treatment failure) and gentamicin for native valve IE and vancomycin, gentamicin and rifampicin for prosthetic valve IE, respectively. Isolates of viridans group streptococci and enterococci should be subtyped and MIC should be determined for penicillin G and aminoglycosides. Antibiotic treatment should be chosen according to sensitivity pattern given 2-6 weeks intravenously. Cardiac valve surgery should be considered early, especially in patients with left-sided IE and/or prosthetic heart valves. Absolute indications for surgery are severe heart failure, paravalvular abscess, lack of response to antibiotic therapy, unstable prosthesis and multiple embolies. Follow-up echocardiography should be performed on clinical indications.

[GEIPC-SEIMC (Study Group for Infections in the Critically Ill Patient of the Spanish Society for Infectious Diseases and Clinical Microbiology) and GTEI-SEMICYUC ( Working Group on Infectious Diseases of the Spanish Society of Intensive Medicine, Critical Care, and Coronary Units) recommendations for antibiotic treatment of gram-positive cocci infections in the critical patient]

In recent years, an increment of infections caused by gram-positive cocci has been documented in nosocomial and hospital-acquired-infections. In diverse countries, a rapid development of resistance to common antibiotics against gram-positive cocci has been observed. This situation is exceptional in Spain but our country might be affected in the near future. New antimicrobials active against these multi-drug resistant pathogens are nowadays available. It is essential to improve our current knowledge about pharmacokinetic properties of traditional and new antimicrobials to maximize its effectiveness and to minimize toxicity. These issues are even more important in critically ill patients because inadequate empirical therapy is associated with therapeutic failure and a poor outcome. Experts representing two scientific societies (Grupo de estudio de Infecciones en el Paciente Crítico de la SEIMC and Grupo de trabajo de Enfermedades Infecciosas de la SEMICYUC) have elaborated a consensus document based on the current scientific evidence to summarize recommendations for the treatment of serious infections caused by gram-positive cocci in critically ill patients.

Recomendaciones GEIPC-SEIMC y GTEI-SEMICYUC para el tratamiento antibiótico de infecciones por cocos grampositivos en el paciente crítico

In recent years, an increment of infections caused by gram-positive cocci has been documented in nosocomial and hospital-acquired infections. In diverse countries, a rapid development of resistance to common antibiotics against gram-positive cocci has been observed. This situation is exceptional in Spain but our country might be affected in the near future. New antimicrobials active against these multi-drug resistant pathogens are nowadays available. It is essential to improve our current knowledge about pharmacokinetic properties of traditional and new antimicrobials to maximize its effectiveness and to minimize toxicity. These issues are even more important in critically ill patients because inadequate empirical therapy is associated with therapeutic failure and a poor outcome. Experts representing two scientific societies (Grupo de estudio de Infecciones en el Paciente Critico de la SEIMC and Grupo de trabajo de Enfermedades Infecciosas de la SEMICYUC) have elaborated a consensus document based on the current scientific evidence to summarize recommendations for the treatment of serious infections caused by gram-positive cocci in critically ill patients.

Clinical manifestations and outcome in Staphylococcus aureus endocarditis among injection drug users and nonaddicts: a prospective study of 74 patients

BACKGROUND

Endocarditis is a common complication in Staphylococcus aureus bacteremia (SAB). We compared risk factors, clinical manifestations, and outcome in a large, prospective cohort of patients with S. aureus endocarditis in injection drug users (IDUs) and in nonaddicts.

METHODS

Four hundred and thirty consecutive adult patients with SAB were prospectively followed up for 3 months. Definite or possible endocarditis by modified Duke criteria was found in 74 patients: 20 patients were IDUs and 54 nonaddicts.

RESULTS

Endocarditis was more common in SAB among drug abusers (46%) than in nonaddicts (14%) (odds ratio [OR], 5.12; 95% confidence interval [CI], 2.65-9.91; P < 0.001). IDUs were significantly younger (27 +/- 15 vs 65 +/- 15 years, P < 0.001), had less ultimately or rapidly fatal underlying diseases (0% vs 37%, P < 0.001) or predisposing heart diseases (20% vs 50%, P = 0.03), and their SAB was more often community-acquired (95% vs 39%, P < 0.001). Right-sided endocarditis was observed in 60% of IDUs whereas 93% of nonaddicts had left-sided involvement (P < 0.001). An extracardiac deep infection was found in 85% of IDUs and in 89% of nonaddicts (P = 0.70). Arterial thromboembolic events and severe sepsis were also equally common in both groups. There was no difference in mortality between the groups at 7 days, but at 3 months it was lower among IDUs (10%) compared with nonaddicts (39%) (OR, 5.73; 95% CI, 1.20-27.25; P = 0.02).

CONCLUSION

S. aureus endocarditis in IDUs was associated with as high complication rates including extracardiac deep infections, thromboembolic events, or severe sepsis as in nonaddicts. Injection drug abuse in accordance with younger age and lack of underlying diseases were associated with lower mortality, but after adjusting by age and underlying diseases injection drug abuse was not significantly associated with mortality.

The role of aminoglycosides in combination with a beta-lactam for the treatment of bacterial endocarditis: a meta-analysis of comparative trials

BACKGROUND

The addition of an aminoglycoside to a beta-lactam for the treatment of patients with infective endocarditis has been supported by data from laboratory and animal studies.

PURPOSE

We sought to review the evidence from the available comparative clinical trials regarding the role of aminoglycosides in combination with a beta-lactam for the treatment of bacterial endocarditis caused by Gram-positive cocci.

DATA SOURCES

The studies for our meta-analysis were retrieved from searches of the PubMed and Cochrane Central Register of Controlled Trials databases, as well as from the references cited in relevant articles. No limits were set regarding the language and date of publication of the studies.

STUDY SELECTION

Included studies were prospective studies that provided comparative data regarding the effectiveness of the treatment and/or mortality in patients receiving monotherapy with a beta-lactam or beta-lactam/aminoglycoside combination therapy.

DATA EXTRACTION

Two independent reviewers performed the literature search, study selection and extraction of data from relevant studies.

DATA SYNTHESIS

No clinical trial comparing beta-lactam monotherapy with beta-lactam/aminoglycoside combination therapy for the treatment of enterococcal endocarditis was found. We performed a meta-analysis of five available comparative trials [four randomized controlled trials (RCTs) and one comparative prospective trial], which included 261 patients with bacterial endocarditis in native valves due to Staphylococcus aureus (four studies) or streptococci of the viridans group (one study). There was no statistically significant difference between beta-lactam monotherapy and beta-lactam/aminoglycoside combination therapy regarding mortality [odds ratio (OR) = 0.59, 95% confidence interval (95% CI) = 0.21-1.66], treatment success (OR = 1.25, 95% CI = 0.49-3.05), treatment success without surgery (OR = 1.66, 95% CI = 0.64-4.30) or relapse of endocarditis (OR = 0.79, 95% CI = 0.15-4.29). Nephrotoxicity was less common in the beta-lactam monotherapy arm than in the beta-lactam/aminoglycoside combination therapy arm (OR = 0.38, 95% CI = 0.16-0.88, P = 0.024). No difference between the two treatment arms was found in subanalyses of the four studies that included only patients with staphylococcal infections in terms of mortality (OR = 0.69, 95% CI = 0.26-1.86, fixed effects model), treatment success (OR = 1.27, 95% CI = 0.47-3.43, fixed effects model) or relapse (OR = 0.76, 95% CI = 0.12-4.92, fixed effects model).

LIMITATIONS

The relatively small number of available comparative trials was the major limitation of this meta-analysis.

CONCLUSIONS

The limited evidence from the available prospective comparative studies does not offer support for the addition of an aminoglycoside to beta-lactam treatment of patients with endocarditis caused by Gram-positive cocci. A large multicentre RCT is necessary to reach a definitive conclusion on this issue.

Infective endocarditis: diagnosis, antimicrobial therapy, and management of complications: a statement for healthcare professionals from the Committee on Rheumatic Fever, Endocarditis, and Kawasaki Disease, Council on Cardiovascular Disease in the Young, and the Councils on Clinical Cardiology, Stroke, and Cardiovascular Surgery and Anesthesia, American Heart Association: endorsed by the Infectious Diseases Society of America

BACKGROUND

Despite advances in medical, surgical, and critical care interventions, infective endocarditis remains a disease that is associated with considerable morbidity and mortality. The continuing evolution of antimicrobial resistance among common pathogens that cause infective endocarditis creates additional therapeutic issues for physicians to manage in this potentially life-threatening illness.

METHODS AND RESULTS

This work represents the third iteration of an infective endocarditis "treatment" document developed by the American Heart Association under the auspices of the Committee on Rheumatic Fever, Endocarditis, and Kawasaki Disease, Council on Cardiovascular Disease of the Young. It updates recommendations for diagnosis, treatment, and management of complications of infective endocarditis. A multidisciplinary committee of experts drafted this document to assist physicians in the evolving care of patients with infective endocarditis in the new millennium. This extensive document is accompanied by an executive summary that covers the key points of the diagnosis, antimicrobial therapy, and management of infective endocarditis. For the first time, an evidence-based scoring system that is used by the American College of Cardiology and the American Heart Association was applied to treatment recommendations. Tables also have been included that provide input on the use of echocardiography during diagnosis and treatment of infective endocarditis, evaluation and treatment of culture-negative endocarditis, and short-term and long-term management of patients during and after completion of antimicrobial treatment. To assist physicians who care for children, pediatric dosing was added to each treatment regimen.

CONCLUSIONS

The recommendations outlined in this update should assist physicians in all aspects of patient care in the diagnosis, medical and surgical treatment, and follow-up of infective endocarditis, as well as management of associated complications. Clinical variability and complexity in infective endocarditis, however, dictate that these guidelines be used to support and not supplant physician-directed decisions in individual patient management.

Guidelines for the antibiotic treatment of endocarditis in adults: report of the Working Party of the British Society for Antimicrobial Chemotherapy

The BSAC Guidelines on Endocarditis were last published in 1998. The Guidelines presented here have been updated and extended to reflect changes in both the antibiotic resistance characteristics of causative organisms and the availability of new antibiotics. Randomized, controlled trials suitable for the development of evidenced-based guidelines in this area are still lacking, and therefore a consensus approach has again been adopted. The Guidelines cover diagnosis and laboratory testing, suitable antibiotic regimens and causative organisms. Special emphasis is placed on common causes of endocarditis, such as streptococci and staphylococci, however, other bacterial causes (such as enterococci, HACEK organisms, Coxiella and Bartonella) and fungi are considered. The special circumstances of prosthetic endocarditis are discussed.

Infective Endocarditis in Intravenous Drug Abusers

Infective endocarditis (IE) is one of the most severe complications in intravenous drug abusers (IVDA). IE usually involves the tricuspid valve, Staphylococcus aureus is the most common etiologic agent, and it has a relatively good prognosis. Currently, between 40% and 90% of IVDA with IE are HIV infected, and the HIV epidemic has caused a decrease in the incidence of this disease, probably due to changes in drug administration habits undertaken by addicts in order to avoid HIV transmission. This review focuses on progress made over the past few years in some aspects of IE in IVDA. The pathogenesis of tricuspid endocarditis is still unknown more than 60 years after the first series. The most important advance in antibiotic therapy is that noncomplicated S. aureus right-sided endocarditis can be successfully treated with an intravenous 2-week course of nafcillin or cloxacillin plus an aminoglycoside, although probably the aminoglycoside administration could be stopped after the first 3 to 5 days. Surgery in HIV-infected IVDA with IE does not worsen the prognosis. Considering the possibility of reinfection in IVDA, prosthetic material is usually avoided. Tricuspid valvulectomy or valve repair should be considered the technique of choice in IVDA with right-sided IE. Replacement of the tricuspid valve by a cryopreserved mitral homograft is the latest introduction into clinical practice. It provides atrioventricular competence, thereby avoiding late right heart failure. Reinfections can be treated medically with a negligible reoperation rate. Overall mortality for HIV-infected or non-HIV-infected IVDA with IE is similar. However, among HIV-infected IVDA, mortality is significantly higher in those who are most severely immunosuppressed, with CD4(+) cell counts below 200/L or with AIDS criteria.

Current best practices and guidelines. Assessment and management of complications in infective endocarditis

The most important complications of endocarditis are congestive heart failure, paravalvular abscess formation, and embolism, especially stroke. In addition, endocarditis may be complicated by septic arthritis, vertebral osteomyelitis, pericarditis, metastatic abscesses and an array of renal problems ranging from immune-complex glomerulonephritis to renal abscesses. Adverse reactions associated with medical treatment of endocarditis can also result in significant complications such as ototoxicity and nephrotoxicity, skin rashes, and serum sickness. This review focuses on the cardiac, embolic, neurologic and renal complications of endocarditis and discusses how these complications influence the clinical management of individual cases in daily practice.

Infective endocarditis in the injection drug user

Although infective endocarditis is certainly not the most common infection seen in injecting drug users, it is the infection that clinicians most commonly think of when they consider infectious complications of injected drug use. The microbiology of infective endocarditis in injection drug users has remained relatively stable over the last several decades. Tricuspid valve endocarditis has been associated most frequently with injection drug use, but recent reports have suggested that involvement of left-sided valves is seen more often now than in the past. The use of transesophageal echocardiography has greatly advanced the ability to diagnose infective endocarditis and the cardiac complications of valvular infection.

Current best practices and guidelines. Assessment and management of complications in infective endocarditis

The most important complications of endocarditis are congestive heart failure, paravalvular abscess formation, and embolism, especially stroke. In addition, endocarditis may be complicated by septic arthritis, vertebral osteomyelitis, pericarditis, metastatic abscesses and an array of renal problems ranging from immune-complex glomerulonephritis to renal abscesses. Adverse reactions associated with medical treatment of endocarditis can also result in significant complications such as ototoxicity and nephrotoxicity, skin rashes, and serum sickness. This review focuses on the cardiac, embolic, neurologic and renal complications of endocarditis and discusses how these complications influence the clinical management of individual cases in daily practice.

Special issues in the management of infective endocarditis caused by gram-positive cocci

Gram-positive cocci, mainly streptococci and staphylococci, continue to cause the majority of cases of infective endocarditis. Among the streptococci causing IE, the long-standing predominance of oral or viridans-group streptococci has progressively faded, while the number of cases caused by "enteric streptococci" (Streptococcus bovis and enterococci) has increased. While most oral streptococci and S. bovis strains remain fully sensitive to penicillin, nutritionally variant streptococci--now renamed Abiotrophia--and enterococci can exhibit resistance to penicillin and/or glycopeptides that makes endocarditis more difficult to treat. Among the staphylococci causing endocarditis, the increasing proportion of coagulase-negative and methicillin-resistant strains observed in recent years has changed the approach to choice of antibiotic therapy. The purpose of this paper is to focus on some new aspects of the management of antibiotic therapy of IE due to streptococci and staphylococci, including recent developments such as once-daily aminoglycoside administration in IE, outpatient antibiotic therapy, and the evaluation of new antibiotics.

Guidelines for the management of intravascular catheter-related infections

These guidelines from the Infectious Diseases Society of America (IDSA), the American College of Critical Care Medicine (for the Society of Critical Care Medicine), and the Society for Healthcare Epidemiology of America contain recommendations for the management of adults and children with, and diagnosis of infections related to, peripheral and nontunneled central venous catheters (CVCs), pulmonary artery catheters, tunneled central catheters, and implantable devices. The guidelines, written for clinicians, contain IDSA evidence-based recommendations for assessment of the quality and strength of the data. Recommendations are presented according to the type of catheter, the infecting organism, and the associated complications.

Intravascular catheter-related infections are a major cause of morbidity and mortality in the United States. Coagulase-negative staphylococci,Staphylococcus aureus, aerobic gram-negative bacilli, andCandida albicansmost commonly cause catheter-related bloodstream infection. Management of catheter-related infection varies according to the type of catheter involved. After appropriate cultures of blood and catheter samples are done, empirical iv antimicrobial therapy should be initiated on the basis of clinical clues, the severity of the patient's acute illness, underlying disease, and the potential pathogen (s) involved. In most cases of nontunneled CVC-related bacteremia and fungemia, the CVC should be removed.

Infective Endocarditis

Despite improvements in antibiotic regimens, patients with infective endocarditis (IE) have a high risk of valve replacement and death. Effective initial treatment depends on two steps: 1) diagnosis of the infecting organism, enabling specific antibiotic therapy, and 2) complete characterization of the anatomic extent of infection. Identification of the infecting organism requires culturing of blood prior to the initiation of antibiotics. Whenever possible, at least three sets of blood cultures should be obtained over 6 to 24 hours and held for 4 weeks if necessary to detect unusual or fastidious organisms. Transesophageal echocardiography (TEE) is usually necessary either to confirm the diagnosis or, most importantly, to identify the local complications of infection, many of which mandate surgery. Despite widespread availability, TEE remains under-used, both for the prevention of unnecessary antibiotic therapy in patients at very low risk for the disease and for the recognition of patients likely to benefit from early surgery. The selection of optimal antibiotic therapy depends on microbiologic data to establish the sensitivities of the specific causative organism. Short courses of antibiotic therapy and outpatient administration of intravenous antibiotics are useful in selected cases.

Recognition, management and prophylaxis of endocarditis

Infective endocarditis (IE) remains a disease with high morbidity and mortality. In recent years, a higher frequency of IE has been observed in the elderly, in intravenous drug users and in patients with prosthetic valves. The diverse manifestations of this disease demand a high degree of suspicion from the practitioner, in order to make an early diagnosis. Advances in and increasing use of echocardiography (especially transoesophageal) allow us to identify valvular changes earlier and more precisely. The use of the new Duke's diagnostic criteria, based on clinical manifestations and microbiological and echocardiographic findings, facilitates the diagnosis and categorisation of IE. An increase in staphylococci and other problem pathogens, such as penicillin-resistant streptococci, enterococci resistant to beta-lactams, aminoglycosides and methicillin-resistant staphylococci has been observed. Important changes have also taken place in the management of IE. There is a clear trend towards the use of shorter treatment courses, oral and once-daily regimens and outpatient programmes, all of which aim to reduce costs and provide patients with improved quality of life. Antibiotic prophylaxis for the prevention of IE is still controversial. In the past few years more rational regimens have been used, and indications are now more precise. In spite of all this, however, few cases are prevented and patient compliance to the prophylaxis regimens remains low.

Pleural effusion in patients infected with the human immunodeficiency virus

In order to analyze the etiology, cytological and biochemical characteristics, and outcome of pleural disease in patients infected with HIV, the medical records of 86 HIV-positive patients with pleural effusion were reviewed. Controls were 106 HIV-negative patients with parapneumonic or tuberculous effusion. Most HIV-positive patients were intravenous drug abusers (95.3%). Pleural effusions in HIV-positive patients were caused by infections in 76 (89.4%) cases. Parapneumonic effusion was diagnosed in 59 patients and tuberculous pleuritis in 15 patients. Staphylococcus aureus was the most frequently isolated bacteria. Parameters for differentiating complicated cases of parapneumonic exudate from uncomplicated cases, such as pleural fluid pH < 7.20 (sensitivity 80% vs. 84.3%), pleural fluid glucose < 35 mg/dl (sensitivity 45% vs. 56.25%) pleural fluid LDH > 1600 UI/l (sensitivity 85% vs. 62.50%), showed similar sensitivity in HIV-positive and HIV-negative patients. Monocytes in pleural fluid were significantly decreased in tuberculous pleuritis in HIV-positive patients (506 +/- 425 vs. 1014 +/- 1196 monocytes/ml, p < 0.05). No significant differences were detected in the outcome of HIV-positive and HIV-negative patients with pleural disease. It can be concluded that the pleural effusion was of predominantly infectious etiology in HIV-positive patients from populations with a high prevalence of intravenous drug abuse. Neither the biochemical parameters in pleural fluid nor the outcome differed significantly between HIV-positive and HIV-negative patients.

Retrospective study of outcome in patients treated for Staphylococcus aureus bacteremia

OBJECTIVE: To investigate whether a change in current treatment practice for Staphylococcus aureus bacteremia from flucloxacillin and aminoglycoside to flucloxacillin and fusidic acid was associated with any changes in outcome. METHODS: A retrospective analysis was carried out of 316 episodes of S. aureus bacteremia diagnosed and treated in a tertiary hospital complex between 1983 and 1993. Outcomes considered were (1) death related to the infection and (2) relapse following cessation of antibiotic therapy. RESULTS: Mortality related to infection, which occurred in 24% of patients, was unrelated to treatment with the combination of flucloxacillin and fusidic acid; however, increasing age was a significant risk factor (OR per decade=1.35, 95% CI=1.18-1.55), and increasing duration of treatment (OR per week of treatment=0.63, 95% CI=0.52-0.77), use of flucloxacillin (OR=0.30, 95% CI=0.14-0.64), presence of an intravascular device (OR=0.39, 95% CI=0.20-0.78) and presence of a skin lesion (OR=0.51, 95% CI=0.26-0.99) were significant protective factors. The only factor significantly related to relapse, which occurred in 11% of patients, was treatment with the combination of flucloxacillin and fusidic acid (OR=0.32, 95% CI=0.12-0.85). There was approximately a 70% reduction in the risk of relapse if this combination was used. CONCLUSIONS: This retrospective analysis suggests a clinically important protective effect of fusidic acid against relapse in patients with S. aureus bacteremia. Although the results were adjusted for potential confounding factors, the possibility of bias remains. There is a need for a prospective randomized trial to evaluate the effectiveness of flucloxacillin and fusidic acid for treating S. aureus bacteremia.

Acute infective endocarditis. Diagnostic and therapeutic approach

Acute bacterial endocarditis (ABE) is clinically distinct from subacute bacterial endocarditis in terms of pathologic virulence, acuteness and severity of illness, complications, and prognosis. The term infectious endocarditis may be useful as a general term but conveys no meaningful clinical information. ABE presents as an acute, fulminant intracardiac infection with fevers (temperature > 102 degrees F) that are caused by highly virulent known pathogens. Septic embolic phenomena, valve dysfunction, and congestive heart failure are characteristic. Parenteral and oral antibiotic treatment regimens are discussed.

Staphylococcus aureus endocarditis in Danish intravenous drug users: high proportion of left-sided endocarditis

In a retrospective study covering the years 1982-1989 episodes of Staphylococcus aureus endocarditis in 51 intravenous drug users were studied. Tricuspid involvement dominated (34/51), but the frequency of left-sided involvement (33.3%) was greater than in earlier reports. Involvement of both sides of the heart was not detected, but 27.8% of the left-sided endocarditis cases had multiple pulmonary infiltrates, indicating that some of them might have had a concomitant right-sided endocarditis. The 2 groups were compared: patients with left-sided endocarditis were significantly older and with a longer time of intravenous drug use. The complication rate was the same (44.1%) as was the duration of antibiotic treatment (median 42 days). In total, five patients underwent surgery, two (5.8%) due to right-sided failure and three (29.4%) because of left-sided endocarditis. The mortality of tricuspid endocarditis was low (2.9%), whereas 5 patients (29.4%) with left-sided involvement died. The patients who died were significantly older and had a shorter duration of symptoms before hospitalization.