Metastatic Foci Of Infection Research Articles

LUNG ABSCESS–A RARE COMPLICATION IN HEMODIALYSIS PATIENTS WITH A CENTRAL VENOUS CATHETER

Nowadays, lung abscess is a rare purulent infection of the lung. In recent decades, its frequency has significantly decreased in connection with the widespread use of antibiotics. Recently, the number of patients with end-stage renal disease undergoing hemodialysis with central venous catheters has increased significantly. One of the most common complications in these patients is catheter-associated infections. Although rare, cases of metastatic infectious foci have also been described. We report two clinical cases of pulmonary abscess secondary to catheter-associated infection in hemodialysis patients with a tunneled catheter and provide a brief overview of the problem.

Septic Pulmonary Emboli Detected by 18F-FDG PET/CT in a Patient with Central Venous Catheter-Related Staphylococcus aureus Bacteremia.

We describe a case of 18F-FDG PET/CT detecting septic pulmonary emboli in a patient with Staphylococcus aureus catheter-related bloodstream infection (CRBSI). The patient, who had an implantable venous access port for chemotherapy, underwent 18F-FDG PET/CT to diagnose unsuspected infectious foci. The PET/CT examination made it possible to offer a suggestive diagnosis and yielded metastatic infectious foci.

Evidence of Clinical Impact Supports a New Petition for Medicare Coverage of 2-[18F]Fluoro-2-Deoxy-D-Glucose Positron Emission Tomography/Computed Tomography in the Evaluation of Staphylococcus aureus Bacteremia: A Focused Literature Review and Call to Action.

Staphylococcus aureus bacteremia (SAB) causes considerable morbidity and mortality and requires comprehensive assessment for metastatic infection. The roles of routine imaging beyond echocardiography in SAB, including 2-[18F]fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (18F-FDG-PET/CT), remain contentious. We performed a literature review of studies reporting impact of 18F-FDG-PET/CT on the clinical management or outcomes of SAB published through 1 March 2022. We identified 7 observational studies in which 18F-FDG-PET/CT frequently identified metastatic foci of infection, revealed foci undetected by prior investigations, led to additional source control procedures, and was associated with fewer infection relapses and lower mortality. Calculated numbers needed to treat for receipt of 18F-FDG-PET/CT were 7-9 to change antimicrobial therapy, 10-27 to lead to an additional source control procedure, and 4-8 to prevent death. These data are comparable to the evidence for clinical impact of other diagnostic modalities accepted as standard of care in SAB, and form a compelling basis for advocacy to expand access to 18F-FDG-PET/CT.

Individualizing the use of [18F]FDG-PET/CT in patients with complicated Staphylococcus aureus bacteremia: experiences from a tertiary care center

Purpose[18F]FDG-PET/CT scanning can help detect metastatic infectious foci and reduce mortality in patients with Staphylococcus aureus bacteremia (SAB), but it is unknown if patients with SAB and an indication for prolonged treatment because of possible endovascular, orthopaedic implant, or other metastatic infection still need [18F]FDG-PET/CT.MethodsIn a retrospective single-center cohort study, we included all consecutive adult patients with SAB between 2013 and 2020 if an [18F]FDG-PET/CT scan was performed and antibiotic treatment was planned for ≥ 6 weeks prior to [18F]FDG-PET/CT. We aimed to identify patients for whom treatment was adjusted due to the results of [18F]FDG-PET/CT, and assessed concordance of [18F]FDG-PET/CT and clinical diagnosis for infected prosthetic material.ResultsAmong 132 patients included, the original treatment plan was changed after [18F]FDG-PET/CT in 22 patients (16.7%), in the majority (n = 20) due to diagnosing or rejecting endovascular (graft) infection. Antibiotic treatment modifications were shortening in 2, iv-oral switch in 3, extension in 13, and addition of rifampicin in 4 patients. Ninety additional metastatic foci based on [18F]FDG-PET/CT results were found in 69/132 patients (52.3%). [18F]FDG-PET/CT suggested vascular graft infection in 7/14 patients who lacked clinical signs of infection, but showed no infection of prosthetic joints or osteosynthesis material in eight patients who lacked clinical signs of such an infection.Conclusion[18F]FDG-PET/CT can help refine treatment for SAB in patients with clinically suspected endovascular infection or vascular grafts, even if 6 weeks treatment is already indicated, but can be safely omitted in other patients who are clinically stable.

Oral Minocycline As Systemic Therapy for Uncomplicated Venous Access Device-Related Bloodstream Infection with Coagulase-Negative Staphylococci in Patients after Allogeneic Hematopoietic Cell Transplantation

Venous access device-related bloodstream infections (VAD-BSIs) with coagulase-negative staphylococci (CoNS) are common complications after allogeneic hematopoietic cell transplantation (alloHCT). So far, the standard systemic antimicrobial therapy for uncomplicated VAD-BSIs with methicillin-resistant CoNS consisted of intravenous (IV) vancomycin (vanco). This approach requires hospitalization, necessitates new competent venous access, exposes patients to potential (mainly renal) toxicity and increases the risk of commensal flora dysbiosis with selection of vanco-resistant enterococci. Patients after alloHCT are particularly at risk of iatrogenic and nosocomial complications. In addition, repeated hospitalizations can impact autonomy and quality of life and are associated with significant costs.Minocycline (mino) is an oral antimicrobial agent that has strong in vitro effects on most Gram positive bacteria and potential anti-biofilm activity, and can be used in the clinic for some CoNS infections. Our infectious disease specialists proposed that systemic therapy with oral mino could be used for the management of uncomplicated VAD-BSIs, primarily when the reference treatment with IV vanco was not possible (renal failure or allergy) or when hospitalization was refused by patients. We retrospectively analyzed the results of this mino-based approach.From January 2012 to December 2020, we treated 24 uncomplicated VAD-BSIs with CoNS in 23 alloHCT patients aged 17-72y with oral mino. Uncomplicated VAD-BSIs were defined as 2 or more blood cultures positive for the same CoNS drawn consecutively peripherally and through the VAD, in patients without signs of sepsis, cellulitis or suppurative thrombophlebitis and without endovascular implant or orthopedic material. VAD were implantable ports (n=17), tunneled catheter (n=1) or PICC-lines (n=6). Pathogens were S. epidermidis (n= 21) or S. haemolyticus (n=3). CoNS were in vitro susceptible to mino according to EUCAST guidelines (with MIC <= 0.5mg/L, predominantly). Mino was administered at a dose of 100 mg BID for 7-14 days. For 8 VAD-BSIs, patients were initially treated with IV vanco for the first 1-3 days followed by oral mino, while 16 VAD-SIBs were managed with oral mino alone. VAD management consisted of catheter removal (for tunneled and PICC-lines, n=7) or antibiotic locks with vanco (n=15) or gentamicin (n=2) administered at least every other day for 14 days (for ports).Overall, clearance of bacteremia (as assessed by negativity of surveillance peripheral blood cultures with the same CoNS drawn between d+3 and +30 after initiation of systemic therapy) was achieved in all but 1 patient (with port, treated with mino alone) who had persistent bacteremia at day +9. No complication such as suppurative thrombophlebitis, endocarditis or metastatic foci of infection was observed in any patient during the 3-month period after initiation of treatment. Among the 17 patients for whom VAD salvage was attempted, VAD decontamination was successful in 10 cases while 4 patients experienced persistently positive VAD-derived blood cultures during the early (d+3 to +14) surveillance period and 3 patients experienced delayed relapse of VAD-BSIs with the same CoNS 1-3 months later (with 1 patient with cellulitis). All these events led to VAD removal. Treatment with mino was well tolerated with the exception of mild skin rash in one patient.Our results in this retrospective cohort suggest that oral mino can be a promising alternative to standard IV vanco for systemic therapy in VAD-BSIs with CoNS and that a strategy combining oral mino and antibiotic locks may salvage VAD in approximately half of the cases. This remains to be confirmed in prospective studies. DisclosuresNo relevant conflicts of interest to declare.

Vitreous and Chorioretinal Lesions in People Who Inject Drugs and Are Hospitalized with Bloodstream and Related Infections

To determine the prevalence of and to characterize vitreous and chorioretinal lesions, to identify causative organisms, and to correlate symptoms with ophthalmic involvement in people who inject drugs and are hospitalized with bloodstream infection (BSI), related metastatic foci of infection (MFI), or both. An academic hospital-based cross-sectional study. Patients admitted with BSI or MFI related to injection drug use (IDU). Patients underwent a complete eye examination within 72 hours of enrollment. Characteristics including gender; age; race; injection drug of choice (DOC); presence of coinfection with hepatitis B, hepatitis C, or human immunodeficiency virus; pathogen causing systemic infection and type of infection; and history of prior infection related to IDU were recorded. Presence of vitreous or chorioretinal findings, or both. Ninety-one unique patients with 96 separate hospitalizations for systemic infection were enrolled from March 28, 2018, through March 30, 2020. Vitreous or chorioretinal involvement was identified in 16 of 96 patients (16.7%). The most common ocular findings were intraretinal or white-centered hemorrhage in 9 of 96 patients, chorioretinal infiltrate in 8 of 96 patients, endophthalmitis in 5 of 96 patients, and cotton wool spots in 3 of 96 patients. Of the patients with ocular involvement, only 7 of 16 patients (44%) were symptomatic, and 5 of these were patients with endophthalmitis; the others showed chorioretinal infiltrates or intraretinal or white-centered hemorrhage and cotton wool spots. Staphylococcus aureus was the most common causative pathogen in patients with and without ocular findings. Presence of ocular symptoms, worse visual acuity, and injection DOC of methamphetamine were correlated with the presence of ocular findings. Patients without ocular symptoms with systemic infections related to IDU may have chorioretinal findings. Further study is needed to characterize better the epidemiologic features of these infections and to identify risk factors for ocular involvement in people who inject drugs.

Distant metastatic foci of infection in adult patients with diabetic foot – not as rare as we think?: case series and review of the literature

Background Diabetic foot is one of the common complications of diabetes mellitus. We report clinical and microbiological characteristics and outcomes of cases with distant metastatic foci of infection arising from diabetic foot. Methods Retrospective review of adult patients with diabetic foot infection or diabetic foot ulcer who demonstrated distant metastatic foci of infection between August 2017 and December 2019. We performed a literature search of similar cases published until June 2020. Results Twelve patients with diabetic foot infection or diabetic foot ulcer with distant metastatic foci of infection were identified. The median age of patients was 67.5 years (range 60.5–73.5 years) and 11 males. The most common distant metastatic foci of infection included endocarditis (n = 7) followed by septic arthritis (n = 3) and spine infections (n = 2). Five patients had multiple site and organ involvement. Staphylococcus aureus was the only organism isolated from blood (n = 11), diabetic foot (n = 7), and metastatic foci (n = 8) sources. Three patients died and three had a relapse of distant metastatic foci of infection. Thirty-eight cases were identified in the literature with similar characteristics. Conclusions Prevalence of distant metastatic foci of infection in adult patients with diabetic foot and burden of illness, in terms of mortality, morbidity, and length of hospital stay, appears to be underreported in the literature. A large prospective study is needed to assess the true prevalence of complications, associated risk factors, outcomes and prognostic factors.

267. Characteristics and Trends of Serratia Blood Stream Infections

Background Serratia is an opportunistic pathogen known to cause an array of infectious presentations including UTIs, pneumonia, wound infections, skin and soft tissue infections, surgical site infections and although rare, endocarditis and bacteremia. The aim of the proposed study is to identify the characteristics of patients with community-acquired Serratia blood stream infection over a five-year period within the TriHealth inpatient population within the Cincinnati, Ohio Region. The study will also examine antibiotic resistance patterns among patients with Serratia bloodstream infections.MethodsThis is a retrospective cohort study of 107 adult patients admitted to two community hospitals from January 2014 to December 2018 with a positive blood culture for Serratia species. A complete data set of 100 patients was analyzed for complications, antibiotic resistance, in-hospital mortality, 90-day mortality, readmission within 90 days and length of Hospital Stay (LOS). Descriptive statistics was performed using frequencies for discrete variables and median (IQR) for continuous variables.ResultsPatients admitted with a positive Serratia blood culture were 38% female with a median (IQR) age of 54.5 years (40.25–71.75) and predominantly white (85%). Forty percent had hepatitis C (HCV) infection and 42% had a history of IV drug use. Most patients were living at home (77%), 18% in long term care and 91% were infected with Serratia marcescens. The most common complications were endocarditis (12%) and osteomyelitis (10%). Extended spectrum beta-lactamase (ESBL) production was confirmed in 13%. In-hospital mortality was 2%, 90-day mortality 2%, readmission 23% and median (IQR) LOS 7(3.25–14.75).PATIENT CHARACTERISTICS AND OUTCOMES (part 1) PATIENT CHARACTERISTICS AND OUTCOMES (part 2) PATIENT CHARACTERISTICS AND OUTCOMES (part 3) ConclusionThis study demonstrates that a high proportion of patients admitted with Serratia bacteremia are IV drugs users and that they have a high prevalence of coexistent HCV infection. Endocarditis and metastatic foci of infection are relatively common. Appropriate empiric antibiotic management should take into account the significant incidence of ESBL production resulting in a prolonged LOS and a high readmission rate.Disclosures All Authors: No reported disclosures

An Antimicrobial Stewardship Intervention Improves Adherence to Standard of Care for Staphylococcus aureus Bloodstream Infection.

Staphylococcus aureus bloodstream infections (SABSI) are a major cause of morbidity and mortality in the United States, and proper management is important to effect cure and prevent metastatic foci of infection. We aimed to utilize our antimicrobial stewardship program (ASP) to improve practices at a large academic hospital system. Our ASP implemented a SABSI educational campaign directed at the hospital medicine, cardiology, and infectious diseases divisions. A stewardship intervention was then begun for all patients with SABSI recommending infectious diseases consultation, transesophageal echocardiography (TEE), source control, and preliminary antibiotic changes. A retrospective review was performed for all SABSI cases 2 years before and after implementation of the SABSI intervention. Two hundred forty-three cases before intervention and 259 after intervention were included. An increase in obtaining follow-up negative blood cultures (79.8% vs. 89.6%), infectious diseases consultation (52.7% vs. 86.5%), TEE (25.5% vs. 54.8%), beta-lactam switch for methicillin-susceptible S. aureus (55.2% vs. 74.4%), and source control (41.2% vs. 57.9%) was demonstrated. We demonstrated similar durations of bacteremia, length of stay, relapse, mortality, and rates of infective endocarditis. Adherence to standard of care for patients with SABSI can be dramatically improved through provider education, leveraging antimicrobial stewardship resources, and infectious diseases consultation.

114. Chorioretinal Lesions in Persons Who Inject Drugs and Are Hospitalized with Bloodstream and Related Infections

BackgroundEye infection is one of the many potential sites of infection in persons who inject drugs (PWID). The purpose of this study was to determine the prevalence of chorioretinal (CR) lesions, identify causative organisms, and correlate symptoms with ophthalmic involvement in PWID hospitalized with bloodstream infection (BSI) and/or related metastatic foci of infection (MFI).MethodsActively using PWID 18 years or older admitted to Wake Forest Baptist Med Ctr with documented BSI or MFI related to injection drug use (IDU) were prospectively enrolled after providing informed consent. All patients, whether or not they had eye symptoms, received a dilated retinal examination as soon as feasible after admission. Ocular symptoms, visual acuity, and ocular examination findings were recorded and fundus photos were obtained as indicated. Patients could be re-enrolled if re-admitted with a different infection.ResultsFifty-three PWID with 55 episodes of disseminated infection related to IDU underwent ophthalmic exams at a median of 7 days post-admission. Mean age was 33.4 years and 51% were female. Twenty (38%) patients had HCV viremia but none had active HIV infection. Heroin was the injection drug of choice in 55% of patients. Of the 55 episodes of systemic infection, 33 were classified as infective endocarditis (IE), 6 were BSI only, 10 were BSI with MFI, and 5 were MFI without active BSI. Nine (17%) patients had CR involvement on examination but only 33% (3/9) were symptomatic. Of those with ocular involvement, 1 had fungal endophthalmitis due to Candida albicans. Single or multifocal subretinal infiltrates were found in 5/9 patients (MSSA 2, MRSA 2, H. parainfluenzae 1), 2/9 had cotton wool spots (S. mitis 1, MRSA 1), and 7/9 had intraretinal or white-centered hemorrhages (MSSA 3, MRSA 2, S. mitis 1, H. parainfluenzae 1). Of the 9 patients with CR lesions, 7 had IE. Interestingly, 3.8% (3/53) had old multifocal CR scars, possibly related to prior disseminated infection.ConclusionPWID admitted with BSI or MFI may have ophthalmic involvement even in the absence of ocular symptoms, especially in the setting of IE. Further study is needed to characterize the epidemiology of these infections, to identify risk factors for ocular involvement, and to optimize diagnosis and management.Disclosures All authors: No reported disclosures.

Unusual Cause of Severe Jaundice in an HIV Infected Patient

Lobar pneumonia as a cause of jaundice with non-obstructive conjugated hyperbilirubinemia is an uncommon complication of pneumococcus. More commonly seen in immunocompromised and elderly patients, it is believed that the offending microbe produces a toxin that directly causes hepatocellular injury and impairment of bilirubin excretion. Biopsies of patients with pneumococcal pneumonia-associated jaundice commonly depict patchy areas of hepatic necrosis and dilated biliary canaliculi without metastatic foci of infection. In the pre-antibiotic era, the prevalence of jaundice in patients with lobar pneumonia was reported to be about 14% and carried significant mortality rates. Seen less commonly today, mortality rates of invasive pneumococcal disease remain as high as 5% to 35%. We present a case of a 29 year-old-male with no medical history presented with subjective fevers, productive cough, dark urine and myalgias for three days. He was profoundly jaundiced without stigmata of chronic liver disease. Computerized tomography (CT) of the chest revealed a right lower lobe pneumonia. The patient had leukocytosis, significant elevation of transaminases, hyperbilirubinemia and was found to be influenza positive. Antibody for human immunodeficiency virus (HIV) was also positive and later confirmed with polymerase chain reaction (PCR). An extensive workup for his jaundice and hyperbilirubinemia was unrevealing and it was deemed that his clinical signs were a result of invasive pneumococcal infection from his pneumonia. The patient was treated with antimicrobials and highly active antiretroviral therapy (HAART). He ultimately had complete resolution of his jaundice and laboratory abnormalities. Although seen infrequently today, unusual manifestations of pneumococcal infection still occur and may be unrecognized in practice.

Salmonella enteritidis Concurrent Spinal Epidural Abscess, Urinary Tract Infection and Endocarditis in an Immunocompetent Host: Case Report and a Review of the Literature

We present a discussion of a rare case of Salmonella non-typhi epidural abscess in an immunocompetent patient without any risk factors with the finding of concurrent mitral valve endocarditis and urinary tract infection. Nontyphoidal salmonella is a reportable food-borne illness which typically presents as a gastrointestinal infection. In immunocompetent individuals, Salmonella infections are often subclinical and almost always self-limited. 5% of nontyphoidal infections progress to a systemic infection from a nonspecific febrile illness often associated with a disseminated bacteremia and metastatic foci of infection with the development of a Salmonella arthritis, urinary tract infection, infection of the central nervous system, bone infection, soft tissue infection. Our case illustrates that Salmonella enteritidis can cause a significant disseminated infection even in the absence of any predisposing factor (if the host is overwhelmed with a high bacterial load).

18F-FDG PET/CT Optimizes Treatment in Staphylococcus Aureus Bacteremia and Is Associated with Reduced Mortality.

Metastatic infection is an important complication of Staphylococcus aureus bacteremia (SAB). Early diagnosis of metastatic infection is crucial, because specific treatment is required. However, metastatic infection can be asymptomatic and difficult to detect. In this study, we investigated the role of 18F-FDG PET/CT in patients with SAB for detection of metastatic infection and its consequences for treatment and outcome. Methods: All patients with SAB at Radboud University Medical Center were included between January 2013 and April 2016. Clinical data and results of 18F-FDG PET/CT and other imaging techniques, including echocardiography, were collected. Primary outcomes were newly diagnosed metastatic infection by 18F-FDG PET/CT, subsequent treatment modifications, and patient outcome. Results: A total of 184 patients were included, and 18F-FDG PET/CT was performed in 105 patients, of whom 99 had a high-risk bacteremia. 18F-FDG PET/CT detected metastatic infectious foci in 73.7% of these high-risk patients. In 71.2% of patients with metastatic infection, no signs and symptoms suggesting metastatic complications were present before 18F-FDG PET/CT was performed. 18F-FDG PET/CT led to a total of 104 treatment modifications in 74 patients. Three-month mortality was higher in high-risk bacteremia patients without 18F-FDG PET/CT performed than in those in whom 18F-FDG PET/CT was performed (32.7% vs. 12.4%, P = 0.003). In multivariate analysis, 18F-FDG PET/CT was the only factor independently associated with reduced mortality (P = 0.005; odds ratio, 0.204; 95% confidence interval, 0.066-0.624). A higher comorbidity score was independently associated with increased mortality (P = 0.003; odds ratio, 1.254; 95% confidence interval, 1.078-1.457). Conclusion:18F-FDG PET/CT is a valuable technique for early detection of metastatic infectious foci, often leading to treatment modification. Performing 18F-FDG PET/CT is associated with significantly reduced 3-mo mortality.

Staphylococcus aureus Bacteremia in Children: The Effect of Methicillin Resistance

Background Staphylococcus aureus bacteremia can occur in children in association with skin/soft tissue, musculoskeletal, respiratory, and endovascular infections. The effect of methicillin resistance on clinical outcomes in children with S. aureus bacteremia has not been clearly described.MethodsSingle center retrospective cohort study over a 5-year period of children ≤18 years hospitalized with monomicrobial S. aureus bacteremia at a tertiary care children’s hospital. We compared baseline characteristics and clinical outcomes between those with methicillin-sensitive S. aureus (MSSA) and methicillin-resistant S. aureus (MRSA) bacteremia using chi-squared test for dichotomous and t-test for continuous variables. We built a multivariable linear regression model to determine the effect of methicillin resistance on duration of bacteremia.ResultsWe identified 334 episodes of S. aureus bacteremia, 233 (70%) with MSSA and 101 (30%) with MRSA. Mean age was 5.4 years; 42.6% were hospital onset infections (49.8% MSSA vs. 25.7% MRSA; P < 0.001); 68.4% (73.3% vs. 55.7%; P = 0.003) occurred in children with chronic medical conditions; and 31.5% occurred in black children (25.9% vs. 44.6%; P = 0.001). Primary site of infection was catheter-related in 31.7% (37.9% vs. 18.7%), musculoskeletal in 28.1% (25.3% vs. 34.1%); skin/soft tissue in 14.2% (13.2% vs. 16.5%); pneumonia in 6.4% (3.2% vs. 13.2%); and no source identified in 11.4% (13.7% vs. 6.6%). Eleven children (3.5%) died within 30 days of bacteremia onset (3.7% vs. 3.0%; P = 0.73), 8 (2.7%) had recurrence within 30 days (2.4% vs. 3.3%; P = 0.65), and 23.4% (18.1% vs. 35.6%; P = 0.001) developed complications including septic emboli or metastatic foci of infection. Duration of bacteremia was 2.2 days (1.8 vs. 3.0; P < 0.001). Adjusting for primary site of infection and performance of a surgical drainage procedure, methicillin resistance was associated with longer duration of bacteremia (+1.2 days; 95% CI: 0.71 to 1.66).ConclusionIn this cohort of children with S. aureus bacteremia, methicillin resistance was associated with community-onset infections, black race, increased risk for complications, and longer duration of bacteremia.Disclosures All authors: No reported disclosures.

New therapeutic approach for the treatment for staphylococcal bacteremia and sepsis

Introduction. Staphylococcal bacteremia is an early and dangerous manifestation of infection, it indicates to the presence of the source of infection in the bloodstream or the dissemination ofgerms from otherfoci, is the cause of high mortality rate. In that the approaches to the treatment for bacteremia/sepsis caused by S.aureus, have surprisingly low conclusiveness and require the optimization of antibiotic therapy, duration of treatment, criteria for cure. The aim of this study was to perform the systematic analysis of the current literature devoted to the problem of antibiotic treatment for staphylococcal infection, primarily followed by bacteremia and sepsis. Objectives of the study: the detection of the problem factors having the negative impact on the effectiveness of the antibiotic treatment of severe staphylococcal infections followed by bacteremia, and prospects for the use of new antibiotics. For the solution of the designated objectives in the scientific medical databases Medscape and Pubmed there was performed the search for the publications on subject headings, covering these problems Conclusion. Bacteremia and sepsis caused by S.aureus is not uncommon and severe infection which occurs everywhere, but remains to be poorly understood. The single isolation of S.aureus from the blood always is to be considered as clinically significant due to the high pathogenicity, high probability of infection and complications, rarity of contamination of blood samples with S.aureus. In cases of the isolation of staphylococci from the blood there is required an immediate and thorough search for any focus of invasion and deep metastatic foci of infection. There are strong evidences that the removal of the origin or the drainage of the locus of infection improves the results of the treatment. There is substantially less certainty about the patients with uncomplicated infections that can receive short courses of ABT. There is discussed the optimal choice of antibiotics, the duration and method of administration for the treatment of S. aureus bacteremia (SAB). Available data indicate to the more higher efficiency of f-lactams compared with glycopeptides for the treatment for infections caused by methicillin-sensitive SAB, the emergence of glycopeptide-intermediate Staphylococcus aureus (GISA) or hetero-GISA reduces the role of glycopeptides in the treatment of bacteremia caused by MRSA. Daptomycin showed the high efficacy in the treatment for severe staphylococcal infections accompanied by bacteremia and sepsis, especially when using in a dose of 6 mg/kg/ day and above. There is insufficient data for the assertion that cephalosporins are also effective as penicillins for treating SAB, but they are probably more effective than vancomycin for the treatment of methicillinsensitive SAB. The optimal duration of treatment is considered to be 10-14 days of intravenous administration for most cases of uncomplicated SAB associated with vascular catheterization, upon condition of the removal of the catheter and low risk of endocarditis.

Clinical characteristics and outcome of brain abscess

To define clinical characteristics, causative organisms, and outcome, and evaluate trends in epidemiology and outcome of brain abscesses over the past 60 years. We performed a systematic review and meta-analysis of studies on brain abscesses published between 1970 and March 2013. Studies were included if they reported at least 10 patients with brain abscesses, included less than 50% extra-axial CNS infections (empyema) without brain abscess, and did not solely report on brain abscesses caused by a single pathogen. We identified 123 studies including 9,699 patients reported between 1935 and 2012. There was a male predominance of 2.4 to 1, and the mean age of patients with brain abscesses was 34 years. The most common causative microorganisms were Streptococcus and Staphylococcus species, comprising 2,000 (34%) and 1,076 (18%) of 5,894 cultured bacteria. Geographical distribution of causative microorganisms over continents was similar and did not substantially change over the past 60 years. Predisposing conditions were present in 8,134 of 9,484 patients (86%) and mostly consisted of contiguous or metastatic foci of infection. The classic triad of fever, headache, and focal neurologic deficits was present in 131 of 668 (20%) of patients. Case fatality rate decreased from 40% to 10% over the past 5 decades, while the rate of patients with full recovery increased from 33% to 70%. The prognosis of patients with brain abscesses has gradually improved over the past 60 years. Important changes over time were the modality of cranial imaging, neurosurgical technique, and antimicrobial regimen.

Subphrenic abscess as a complication of hemodialysis catheter-related infection.

We describe an unusual case of subphrenic abscess complicating a central venous catheter infection caused by Pseudomonas aeruginosa in a 59-year-old woman undergoing hemodialysis. The diagnosis was made through computed tomography, and Pseudomonas aeruginosa was isolated from the purulent drainage of the subphrenic abscess, the catheter tip and exit site, and the blood culture samples. A transesophageal echocardiography showed a large tubular thrombus in superior vena cava, extending to the right atrium, but no evidence of endocarditis or other metastatic infectious foci. Catheter removal, percutaneous abscess drainage, anticoagulation, and antibiotics resulted in a favourable outcome.

Editorial Commentary: A Quality-of-Care Bundle for Treatment of Staphylococcus aureus Bacteremia: Ready for Prime Time?

Staphylococcus aureus is the most frequent cause of healthcare-associated bloodstream infections in the United States [1] and among the most common etiologies of bloodstream infections worldwide [2]. By sheer volume alone, S. aureus bacteremia (SAB) imposes a significant burden on the healthcare system. This burden is further amplified by the high likelihood of serious complications associated with this disease including metastatic infections and infective endocarditis. In an analysis of a large database of 59 US hospitals, SAB, and, in particular bacteremia due to methicillin-resistant S. aureus, was associated with a higher mortality, longer length of stay, and greater total hospital charges compared to bacteremia from any other pathogen [1]. The cost per episode of SAB is substantial, especially among high-risk patients; the mean cost among patients undergoing hemodialysis is $24 034 [3] and ranges from $40 000 to $70 000 [4] among those with prosthetic devices. Given the enormous impact of SAB on healthcare resource utilization, there is a major incentive to prevent and optimize management of SAB. Evidence-based bundles of care have received increased attention in recent years as structured ways to improve processes of care and patient outcomes. The fundamental premise is that the entire “bundle” of interventions, when collectively and consistently implemented, results in better outcomes than when the interventions are implemented individually. For example, the central line bundle has been highlighted as one of the most successful and widely adopted bundles of care, resulting in significant and sustained declines in the rates of central line–associated bloodstream infections (CLABSIs) [5, 6]. Between 2001 and 2009, there was a 58% reduction in the overall US CLABSI rate with a 73% reduction in CLABSI due to S. aureus [7]. With respect to management of SAB, multiple studies have demonstrated improved outcomes [8–10] as well as mortality benefit [11–15] among patients with SAB who are managed formally by infectious disease (ID) consultants. In these studies, ID consultation has been shown to increase adherence to several standards (with some variability by study in the standards assessed) that are deemed to be important in the management of patients with SAB including follow-up blood cultures after initial positive, identification of metastatic foci of infection and source control, echocardiography, treatment of methicillinsusceptible infection with β-lactam therapy, and appropriate duration of therapy. The study by Lopez-Cortes et al, published in this issue of Clinical Infectious Diseases, is the first that has evaluated the impact of a standardized bundle of interventions for management of SAB in multiple centers. Lopez-Cortes et al implemented amulticenter intervention including 12 tertiary care hospitals in Spain and applied 6 quality-of-care indicators for management of SAB selected based on review of the literature: (1) follow-up blood cultures 48– 96 hours after initiation of antimicrobial therapy; (2) early source control within 72 hours (ie, catheter removal, abscess drainage); (3) echocardiography in patients with complicated bacteremia or predisposing condition for endocarditis; (4) use of a βlactam antibiotic as definitive therapy for treatment of methicillin-susceptible S. aureus; (5) measurement of vancomycin trough levels with dose adjustment to target levels of 15–20 mg/L; and (6) appropriate treatment duration based on complexity of infection. The intervention Received 22 July 2013; accepted 23 July 2013; electronically published 8 August 2013. Correspondence: Catherine Liu, MD, Division of Infectious Diseases, University of California, San Francisco, 513 Parnassus Ave, S-380, San Francisco, CA 94143 (catherine.liu@ucsf. edu). Clinical Infectious Diseases 2013;57(9):1234–6 © The Author 2013. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals. permissions@oup.com. DOI: 10.1093/cid/cit502

The value of 18F-FDG PET/CT in diagnosing infectious endocarditis

Early detection of infectious endocarditis is challenging. For diagnosing infectious endocarditis, the revised Duke criteria are the gold standard. Evidence of endocardial involvement on echocardiography is a major criterion, but sensitivity and specificity of echocardiography are not optimal. Here we investigated the utility of (18)F-fluorodeoxyglucose (FDG) positron emission tomography and computed tomography (PET/CT) to diagnose infectious endocarditis in patients with gram-positive bacteraemia. Seventy-two patients with gram-positive bacteraemia were prospectively included. Patients with a positive blood culture growing Staphylococcus aureus, Streptococcus species or Enterococcus species were eligible when a risk factor for developing metastatic infectious foci was present. Infectious endocarditis was defined according to the revised Duke criteria. All patients underwent (18)F-FDG PET/CT and echocardiography. (18)F-FDG uptake in or around the heart valves was evaluated independently by two nuclear medicine physicians. Sensitivity for diagnosing infectious endocarditis with (18)F-FDG PET/CT was 39% and specificity was 93%. The positive predictive value was 64% and negative predictive value was 82%. The mortality rate in patients without infectious endocarditis and without increased (18)F-FDG uptake in or around the heart valves was 18%, and in patients without infectious endocarditis but with high (18)F-FDG uptake in or around the heart valves the mortality rate was 50% (p = 0.181). (18)F-FDG PET/CT is currently not sufficiently adequate for the diagnosis of infectious endocarditis because of its low sensitivity. Improvements such as patient preparation with low carbohydrate-fat allowed diet and technical advances in the newest PET/CT scanners may increase sensitivity in future studies.

Improving the management of Staphylococcus aureus bacteraemia, including MRSA.

Staphylococcus aureus bacteraemia is a serious infection associated with significant complications, including recurrence of bacteraemia, endocarditis and metastatic foci of infection. The management of these patients is often complex, involving appropriate source control, a thorough review and investigations to exclude metastatic foci and infective endocarditis. Additionally, a prolonged course of intravenous antibiotics is often required.As part of our quality improvement project, the following five aspects were evaluated in 56 patients with S. aureus bacteraemia at two District General Hospitals: 1) adequate and timely removal of the source of bacteraemia, 2) echocardiography to exclude endocarditis, 3) repeat blood culture to prove clearance of bacteraemia, 4) adequate duration and choice of antibiotics and 5) documentation of bacteraemia in the discharge summary.After an initial review revealed several areas for improvement, we instituted five Plan-Do-Study-Act learning cycles which involved: teaching microbiology trainees and junior doctors, improving clinical liaison and communication between the microbiology team and clinicians, as well as a clinical review of patients by the microbiology team where appropriate.The post-intervention review evaluated 24 patients with S. aureus bacteraemia between November 2012 and May 2013. The proportion of patients undergoing an echocardiogram improved from 49% to 88%. Another marked improvement was seen in the timely obtaining of clearance blood cultures, with 88% of patients having clearance blood cultures within the 2-4 day window, compared to 56% pre-intervention. 70% of patients with uncomplicated S. aureus bacteraemia received an appropriate antibiotic course post-intervention, compared with 59% pre-intervention. Documentation of the S. aureus bacteraemia in the discharge summary improved from 65% to 75%. The support of the entire microbiology team was pivotal in the successful outcome of the quality improvement project.