The Utility of Risk Factors to Define Complicated Staphylococcus aureus Bacteremia in a Setting With Low Methicillin-Resistant S. aureus Prevalence.

INTRODUCTION: Recommended duration of antibiotic treatment of Staphylococcus aureus bacteremia (SAB) is frequently based on distinguishing uncomplicated and complicated SAB, and several risk factors at the onset of infection have been proposed to define complicated SAB. Predictive values of risk factors for complicated SAB have not been validated, and consequences of their use on antibiotic prescriptions are unknown. METHODS: In a prospective cohort, patients with SAB were categorized as complicated or uncomplicated through adjudication (reference definition). Associations and predictive values of 9 risk factors were determined, compared with the reference definition, as was accuracy of Infectious Diseases Society of America (IDSA) criteria that include 4 risk factors, and the projected consequences of applying IDSA criteria on antibiotic use. RESULTS: Among 490 patients, 296 (60%) had complicated SAB. In multivariable analysis, persistent bacteremia (odds ratio [OR], 6.8; 95% confidence interval [CI], 3.9-12.0), community acquisition of SAB (OR, 2.9; 95% CI, 1.9-4.7) and presence of prosthetic material (OR, 2.3; 95% CI, 1.5-3.6) were associated with complicated SAB. Presence of any of the 4 risk factors in the IDSA definition of complicated SAB had a positive predictive value of 70.9% (95% CI, 65.5-75.9) and a negative predictive value of 57.5% (95% CI, 49.1-64.8). Compared with the reference, IDSA criteria yielded 24 (5%) false-negative and 90 (18%) false-positive classifications of complicated SAB. Median duration of antibiotic treatment of these 90 patients was 16 days (interquartile range, 14-19), all with favorable clinical outcome. CONCLUSIONS: Risk factors have low to moderate predictive value to identify complicated SAB and their use may lead to unnecessary prolonged antibiotic use.

External Validation of the 2023 Duke-International Society for Cardiovascular Infectious Diseases Diagnostic Criteria for Infective Endocarditis.

BACKGROUND: The 2023 Duke-International Society of Cardiovascular Infectious Diseases (ISCVID) criteria for infective endocarditis (IE) were introduced to improve classification of IE for research and clinical purposes. External validation studies are required. METHODS: We studied consecutive patients with suspected IE referred to the IE team of Amsterdam University Medical Center (from October 2016 to March 2021). An international expert panel independently reviewed case summaries and assigned a final diagnosis of "IE" or "not IE," which served as the reference standard, to which the "definite" Duke-ISCVID classifications were compared. We also evaluated accuracy when excluding cardiac surgical and pathologic data ("clinical" criteria). Finally, we compared the 2023 Duke-ISCVID with the 2000 modified Duke criteria and the 2015 and 2023 European Society of Cardiology (ESC) criteria. RESULTS: A total of 595 consecutive patients with suspected IE were included: 399 (67%) were adjudicated as having IE; 111 (19%) had prosthetic valve IE, and 48 (8%) had a cardiac implantable electronic device IE. The 2023 Duke-ISCVID criteria were more sensitive than either the modified Duke or 2015 ESC criteria (84.2% vs 74.9% and 80%, respectively; P < .001) without significant loss of specificity. The 2023 Duke-ISCVID criteria were similarly sensitive but more specific than the 2023 ESC criteria (94% vs 82%; P < .001). The same pattern was seen for the clinical criteria (excluding surgical/pathologic results). New modifications in the 2023 Duke-ISCVID criteria related to "major microbiological" and "imaging" criteria had the most impact. CONCLUSIONS: The 2023 Duke-ISCVID criteria represent a significant advance in the diagnostic classification of patients with suspected IE.

Positive Impact of [18F]FDG-PET/CT on Mortality in Patients With Staphylococcus aureus Bacteremia Explained by Immortal Time Bias.

BACKGROUND: Several studies have suggested that in patients with Staphylococcus aureus bacteremia (SAB) [18F] fluorodeoxyglucose positron emission tomography/computed tomography ([18F]FDG-PET/CT) improves outcome. However, these studies often ignored possible immortal time bias. METHODS: Prospective multicenter cohort study in 2 university and 5 non-university hospitals, including all patients with SAB. [18F]FDG-PET/CT was performed on clinical indication as part of usual care. Primary outcome was 90-day all-cause mortality. Effect of [18F]FDG-PET/CT was modeled with a Cox proportional hazards model using [18F]FDG-PET/CT as a time-varying variable and corrected for confounders for mortality (age, Charlson score, positive follow-up cultures, septic shock, and endocarditis). Secondary outcome was 90-day infection-related mortality (assessed by adjudication committee) using the same analysis. In a subgroup-analysis, we determined the effect of [18F]FDG-PET/CT in patients with high risk of metastatic infection. RESULTS: Of 476 patients, 178 (37%) underwent [18F]FDG-PET/CT. Day-90 all-cause mortality was 31% (147 patients), and infection-related mortality was 17% (83 patients). The confounder adjusted hazard ratio (aHR) for all-cause mortality was 0.50 (95% confidence interval [CI]: .34-.74) in patients that underwent [18F]FDG-PET/CT. Adjustment for immortal time bias changed the aHR to 1.00 (95% CI .68-1.48). Likewise, after correction for immortal time bias, [18F]FDG-PET/CT had no effect on infection-related mortality (cause specific aHR 1.30 [95% CI .77-2.21]), on all-cause mortality in patients with high-risk SAB (aHR 1.07 (95% CI .63-1.83) or on infection-related mortality in high-risk SAB (aHR for 1.24 [95% CI .67-2.28]). CONCLUSIONS: After adjustment for immortal time bias [18F]FDG-PET/CT was not associated with day-90 all-cause or infection-related mortality in patients with SAB.

The 2023 Duke-International Society for Cardiovascular Infectious Diseases Criteria for Infective Endocarditis: Updating the Modified Duke Criteria.

The microbiology, epidemiology, diagnostics, and treatment of infective endocarditis (IE) have changed significantly since the Duke Criteria were published in 1994 and modified in 2000. The International Society for Cardiovascular Infectious Diseases (ISCVID) convened a multidisciplinary Working Group to update the diagnostic criteria for IE. The resulting 2023 Duke-ISCVID IE Criteria propose significant changes, including new microbiology diagnostics (enzyme immunoassay for Bartonella species, polymerase chain reaction, amplicon/metagenomic sequencing, in situ hybridization), imaging (positron emission computed tomography with 18F-fluorodeoxyglucose, cardiac computed tomography), and inclusion of intraoperative inspection as a new Major Clinical Criterion. The list of "typical" microorganisms causing IE was expanded and includes pathogens to be considered as typical only in the presence of intracardiac prostheses. The requirements for timing and separate venipunctures for blood cultures were removed. Last, additional predisposing conditions (transcatheter valve implants, endovascular cardiac implantable electronic devices, prior IE) were clarified. These diagnostic criteria should be updated periodically by making the Duke-ISCVID Criteria available online as a "Living Document."

Value of diagnosing immunological phenomena in patients with suspected endocarditis.

PURPOSE: Immunological phenomena are a minor criteria in the modified Duke Criteria for endocarditis. Given the changes in epidemiology and diagnostics, the added value of determining these phenomena in today's patients with suspected endocarditis is unknown. METHODS: In a retrospective cohort study of all patients with suspected endocarditis admitted to our hospital and discussed in our endocarditis team, we determined the proportion of patients classified as definite endocarditis because of either positive IgM rheumatoid factor (IgM RF), haematuria, or Roth's spots on ophthalmology consultation. We also determined diagnostic accuracy of each of these immunological phenomena separately and combined. RESULTS: Of 285 patients included, 138 (48%) had definite endocarditis and at least one immunological test was performed in 222 patients (78%). Elevated IgM RF was found in 22 of 126 patients tested (17%), haematuria in 78 of 196 tested (40%) and Roth's spots in six of 120 tested (5%). Eighteen of 138 patients with definite IE (13%) were classified as such because of a positive IgM RF, haematuria or Roth's spots. Haematuria had the highest sensitivity: 50.5% (95% CI 40.4-60.6) and Roth's spots the highest specificity: 98.3% (95% CI 90.8-99.9). The diagnostic accuracy results were robust in a sensitivity analysis aimed at avoiding incorporation bias. CONCLUSION: Among patients with a clinical suspicion of endocarditis, recommended systematic testing for immunological phenomena helped classify more patients as definite IE and is useful to confirm the diagnosis of endocarditis.

Prediction Rules for Ruling Out Endocarditis in Patients With Staphylococcus aureus Bacteremia.

BACKGROUND: Staphylococcus aureus bacteremia (SAB) is in 10% to 20% of cases complicated by infective endocarditis. Clinical prediction scores may select patients with SAB at highest risk for endocarditis, improving the diagnostic process of endocarditis. We compared the accuracy of the Prediction Of Staphylococcus aureus Infective endocarditiseTime to positivity, Iv drug use, Vascular phenomena, preExisting heart condition (POSITIVE), Predicting Risk of Endocarditis Using a Clinical Tool (PREDICT), and VIRSTA scores for classifying the likelihood of endocarditis in patients with SAB. METHODS: Between August 2017 and September 2019, we enrolled consecutive adult patients with SAB in a prospective cohort study in 7 hospitals in the Netherlands. Using the modified Duke Criteria for definite endocarditis as reference standard, sensitivity, specificity, negative predictive (NPV), and positive predictive values were determined for the POSITIVE, PREDICT, and VIRSTA scores. An NPV of at least 98% was considered safe for excluding endocarditis. RESULTS: Of 477 SAB patients enrolled, 33% had community-acquired SAB, 8% had a prosthetic valve, and 11% a cardiac implantable electronic device. Echocardiography was performed in 87% of patients, and 42% received transesophageal echocardiography (TEE). Eighty-seven (18.2%) had definite endocarditis. Sensitivity was 77.6% (65.8%-86.9%), 85.1% (75.8%-91.8%), and 98.9% (95.7%-100%) for the POSITIVE (n = 362), PREDICT, and VIRSTA scores, respectively. NPVs were 92.5% (87.9%-95.8%), 94.5% (90.7%-97.0%), and 99.3% (94.9%-100%). For the POSITIVE, PREDICT, and VIRSTA scores, 44.5%, 50.7%, and 70.9% of patients with SAB, respectively, were classified as at high risk for endocarditis. CONCLUSIONS: Only the VIRSTA score had an NPV of at least 98%, but at the expense of a high number of patients classified as high risk and thus requiring TEE. CLINICAL TRIALS REGISTRATION: Netherlands Trial Register code 6669.

Acute hepatitis C infection among adults with HIV in the Netherlands between 2003 and 2016: a capture-recapture analysis for the 2013 to 2016 period.

BackgroundWith regards to the global strategy towards eliminating viral hepatitis, reliable surveillance systems are essential to assess the national response for eliminating hepatitis C virus (HCV).AimWe aimed to assess the completeness of the two national registries with data on acute HCV infection in people with HIV, and estimated the number of acute HCV infections among adults (aged ≥ 18 years) with HIV in the Netherlands.MethodsIn this observational study, cases of HCV infection and reinfection among adults with a positive or unknown HIV-serostatus were identified from 2003 to 2016 in two national registries: the ATHENA cohort and the National Registry for Notifiable Diseases. For 2013-2016, cases were linked, and two-way capture-recapture analysis was carried out.ResultsDuring 2013-2016, there were an estimated 282 (95% confidence interval (CI): 264-301) acute HCV infections among adults with HIV. The addition of cases with an unknown HIV-serostatus increased the matches (from n = 107 to n = 129), and subsequently increased the estimated total: 330 (95%CI: 309-351). Under-reporting was estimated at 14-20%.ConclusionUnder-reporting of acute HCV infection among people with HIV could partially be explained by an unknown HIV-serostatus, or by differences in HCV stage (acute or chronic) at first diagnosis. Surveillance data should ideally include both acute and chronic HCV infections, and enable to distinguish these as well as initial- and re-infections. National surveillance of acute HCV can be improved by increased notification of infections.

SNP rs688 within the low-density lipoprotein receptor (LDL-R) gene associates with HCV susceptibility.

BACKGROUND & AIMS: Despite high-risk behaviour, 10%-20% of HCV multiple exposed individuals remain uninfected (MEU), whilst the remainder become infected (MEI). We hypothesize that host factors play a role in HCV susceptibility. We aimed to identify polymorphisms in host genes that encode for proteins involved in viral entry: CD81, Scavenger receptor 1 (SR-1), Low-density lipoprotein receptor (LDL-R), Claudin-1 (CLDN1), Occludin (OCLN) and Niemann-Pick C1-like 1 (NPC1L1). METHODS: Multiple exposed infected and MEU from two observational cohorts were selected. From the MSM study of acute infection with HCV (MOSAIC), HIV-1 infected MEU cases (n = 30) and HIV-1 infected MEI controls (n = 32) were selected based on reported high-risk behaviour. From the Amsterdam Cohorts Studies (ACS) injecting drug users (IDU) cohort, MEU cases (n = 40) and MEI controls (n = 22) were selected who injected drugs for ≥2 years, in the nineties, when HCV incidence was high. Selected single nucleotide polymorphisms (SNPs) were determined by sequencing or SNP assays. RESULTS: No associations were found for SNPs within genes coding for CD81, SR-1, Claudin-1 or Occludin between the MEU and MEI individuals from either cohort. We did observe a significant association for rs688 within the LDL-R gene with HCV infection (OR: 0.41 P = 0.001), however, LDL cholesterol levels did not vary between individuals carrying the differential SNPs. Additionally, a marginal significant effect was found for rs217434 and rs2072183 (OR: 2.07 P = 0.032 and OR: 1.76 P = 0.039, respectively) within NPC1L1. CONCLUSIONS: Our results demonstrate that the rs688 SNP within the LDL-R gene associates with HCV susceptibility through mucosal as well as intravenous exposure.

DC-SIGN Polymorphisms Associate with Risk of Hepatitis C Virus Infection Among Men who Have Sex with Men but not Among Injecting Drug Users.

We aimed to identify whether genetic polymorphisms within L-SIGN or DC-SIGN correlate with hepatitis C virus (HCV) susceptibility. A men who have sex with men (MSM) and an injecting drug users (IDU) cohort of HCV cases and multiple-exposed uninfected controls were genotyped for numerous L-SIGN and DC-SIGN polymorphisms. DC-SIGN single nucleotide polymorphisms (SNPs) -139, -871, and -939 correlated with HCV acquisition in the MSM cohort only. When the same SNPs were introduced into a transcription activity assay they demonstrated a reduction in expression with predicted alteration in binding of transcription factors. DC-SIGN promoter SNPs correlated with risk of HCV acquisition via sexual but not IDU exposure, likely through modulation of mRNA expression levels.

Characterization of Hepatitis C Virus (HCV) Envelope Diversification from Acute to Chronic Infection within a Sexually Transmitted HCV Cluster by Using Single-Molecule, Real-Time Sequencing.

In contrast to other available next-generation sequencing platforms, PacBio single-molecule, real-time (SMRT) sequencing has the advantage of generating long reads albeit with a relatively higher error rate in unprocessed data. Using this platform, we longitudinally sampled and sequenced the hepatitis C virus (HCV) envelope genome region (1,680 nucleotides [nt]) from individuals belonging to a cluster of sexually transmitted cases. All five subjects were coinfected with HIV-1 and a closely related strain of HCV genotype 4d. In total, 50 samples were analyzed by using SMRT sequencing. By using 7 passes of circular consensus sequencing, the error rate was reduced to 0.37%, and the median number of sequences was 612 per sample. A further reduction of insertions was achieved by alignment against a sample-specific reference sequence. However, in vitro recombination during PCR amplification could not be excluded. Phylogenetic analysis supported close relationships among HCV sequences from the four male subjects and subsequent transmission from one subject to his female partner. Transmission was characterized by a strong genetic bottleneck. Viral genetic diversity was low during acute infection and increased upon progression to chronicity but subsequently fluctuated during chronic infection, caused by the alternate detection of distinct coexisting lineages. SMRT sequencing combines long reads with sufficient depth for many phylogenetic analyses and can therefore provide insights into within-host HCV evolutionary dynamics without the need for haplotype reconstruction using statistical algorithms.IMPORTANCE Next-generation sequencing has revolutionized the study of genetically variable RNA virus populations, but for phylogenetic and evolutionary analyses, longer sequences than those generated by most available platforms, while minimizing the intrinsic error rate, are desired. Here, we demonstrate for the first time that PacBio SMRT sequencing technology can be used to generate full-length HCV envelope sequences at the single-molecule level, providing a data set with large sequencing depth for the characterization of intrahost viral dynamics. The selection of consensus reads derived from at least 7 full circular consensus sequencing rounds significantly reduced the intrinsic high error rate of this method. We used this method to genetically characterize a unique transmission cluster of sexually transmitted HCV infections, providing insight into the distinct evolutionary pathways in each patient over time and identifying the transmission-associated genetic bottleneck as well as fluctuations in viral genetic diversity over time, accompanied by dynamic shifts in viral subpopulations.

Boceprevir, peginterferon and ribavirin for acute hepatitis C in HIV infected patients.

BACKGROUND & AIMS: Acute hepatitis C virus infections (AHCV) are prevalent among HIV positive men having sex with men and generally treated with pegylated interferon-alpha (PegIFN) and ribavirin (RBV) during 24weeks. The addition of a protease inhibitor could shorten therapy without loss of efficacy. METHODS: We performed an open-label, single arm study to investigate the efficacy and safety of a 12-week course of boceprevir, PegIFN and RBV for AHCV genotype 1 infections in 10 Dutch HIV treatment centers. The primary endpoint of the study was achievement of sustained virological response rate at week 12 (SVR12) in patients reaching a rapid viral response at week 4 (RVR4) and SVR12 in the intent to treat (ITT) entire study population was the most relevant secondary endpoint. RESULTS: One hundred twenty-seven AHCV patients were screened in 16 months, of which 65 AHCV genotype 1 patients were included. After spontaneous clearance in six patients and withdrawal before treatment initiation in two, 57 started therapy within 26 weeks after infection. RVR4 rate was 72%. SVR12 rate was 100% in the RVR4 group. SVR12 rate in the ITT group was 86% and comparable to the SVR12 rate of 84% in 73 historical controls treated for 24 weeks with PegIFN and RBV in the same study centers. CONCLUSION: With the addition of boceprevir to PegIFN and RBV, treatment duration of AHCV genotype 1 can be reduced to 12 weeks without loss of efficacy. Given the high drug costs and limited availability of interferon-free regimens, boceprevir PegIFN and RBV can be a considered a valid treatment option for AHCV. ClinicalTrials.gov, number NCT01912495.

Resistance-associated polymorphisms in Dutch hepatitis C genotype 1a patients with and without HIV infection.

UNLABELLED:  Background and aim. Resistance-associated variants (RAVs) on the NS3 region of the hepatitis C virus (HCV) may be relevant for antiviral therapy, but data in human immunodeficiency virus (HIV) coinfected patients are scarce. We assessed frequencies of NS3 RAVs in patients infected with HCV genotype 1a with or without HIV coinfection. MATERIAL AND METHODS: HCV NS3 amino acids 1-181 were sequenced by the Sanger method and analyzed for RAVs. RAVs and their distribution between HCV genotype 1a clade I and II viruses were compared between HIV-infected versus HIV-uninfected patients. RESULTS: 148 samples were available (n = 68 HIV and n = 80 non-HIV). Relative frequency of clade I and clade II was significantly different between HIV (85% and 15%) and non-HIV groups (49% and 51%). Overall, HIV infected patients exhibited significantly lower prevalence of RAVs than HIV-uninfected patients (62% vs. 79%, p = 0.03). However, Q80K prevalence was significantly higher in HIV-infected subjects (50% vs. 24%, p = 0.001), whereas prevalence of S122D/G/N/S (2% vs. 16%, p = 0.002) and N174G/N/S (10% vs. 55%, p < 0.0001) polymorphisms were significantly lower. Q80K was found exclusively in clade I viruses. S122 (3% vs. 22%, p=0.001) and N174 (13% vs. 75%, p<0.0001) polymorphisms had significantly lower prevalence in clade I than clade II viruses. CONCLUSIONS: In the Netherlands, prevalence of clade I viruses and Q80K was significantly higher in HCV genotype 1a infected patients with HIV coinfection than in those without HIV coinfection. Prevalence of N174 and S122 polymorphisms was significantly higher in clade II than clade I viruses.

Hepatitis C virus (HCV) antibody dynamics following acute HCV infection and reinfection among HIV-infected men who have sex with men.

BACKGROUND: A decline of hepatitis C virus (HCV) antibody titers (anti-HCV), ultimately resulting in seroreversion, has been reported following clearance of viremia in both acute and chronic HCV infection. However, frequency of seroreversion remains unknown in human immunodeficiency virus (HIV)/HCV-coinfected patients. We describe anti-HCV dynamics among HIV-infected men who have sex with men (MSM) following acute HCV infection and reinfection. METHODS: Primary acute HCV infection was assumed when a subject was anti-HCV negative prior to the first positive HCV RNA test. Anti-HCV was measured at least annually in 63 HIV-infected MSM, with a median follow-up of 4.0 years (interquartile range [IQR], 2.5-5.7 years). Time from HCV infection to seroconversion, and from seroconversion to seroreversion, was estimated using the Kaplan-Meier method. Longitudinal anti-HCV patterns were studied using a random-effects model to adjust for repeated measures. RESULTS: Median time from HCV infection to seroconversion was 74 days (IQR, 47-125 days). Subjects who cleared HCV RNA (n = 36) showed a significant decrease in anti-HCV levels (P < .001). Among 31 subjects with sustained virologic response (SVR), anti-HCV became undetectable during follow-up in 8; cumulative incidence of seroreversion within 3 years after seroconversion was 37% (95% confidence interval, 18%-66%). Eighteen subjects became reinfected during follow-up; this coincided with a subsequent increase in anti-HCV reactivity. CONCLUSIONS: A decline of anti-HCV reactivity was associated with HCV RNA clearance. Seroreversion was very common following SVR. Upon reinfection, anti-HCV levels increased again. Monitoring anti-HCV levels might therefore be an effective alternative for diagnosis of HCV reinfection.

Acute kidney injury in Staphylococcus aureus bacteraemia: a recurrent events analysis.

OBJECTIVES: To estimate risk factors for acute kidney injury (AKI) and the effect of AKI on mortality in Staphylococcus aureus bacteraemia, while taking into account recurrent AKI episodes, competing risks, time-varying variables, and time-varying effects. METHODS: We performed an unplanned analysis using data from a multicentre cohort study of patients with Staphylococcus aureus bacteraemia (SAB). The primary outcome was cumulative incidence of AKI, according to Kidney Disease Improving Global Outcomes definitions. RESULTS: We included 453 patients in this study of whom 194 (43%) patients experienced one or more AKI episodes. Age (hazard ratio (HR) 1.013, 95% CI 1.001-1.024), Charlson comorbidity index (HR 1.07, 95% CI 1.01-1.14), prior chronic kidney disease (HR 1.76, 95% CI 1.28-2.42), septic shock (HR 3.28, 95% CI 2.31-4.66), persistent bacteraemia (HR 1.53, 95% CI 1.08-2.17), and vancomycin therapy (HR 1.80, 95% CI 1.05-3.09) were independently associated with AKI, but flucloxacillin, cefazolin, rifampicin, and aminoglycoside therapy were not. After adjustment for confounders and immortal time bias, AKI was associated with an increased risk of 90-day mortality (HR 4.26, 95% CI 2.91-6.23). DISCUSSION: The incidence of AKI in SAB is high and a substantial proportion of patients develop recurrent episodes of AKI after recovery. AKI is specifically linked to the use of vancomycin and not to anti-staphylococcal penicillins. The clinical outcome of patients with SAB complicated by AKI is worse than previously estimated.

Clinical consequences of increased ciprofloxacin and gentamicin resistance in patients with Escherichia coli bacteraemia in the Netherlands.

BACKGROUND: Escherichia coli is a common cause of bacteraemia and is increasingly resistant to ciprofloxacin and gentamicin. The primary objective of this study was to investigate how often this leads to inadequate initial antimicrobial treatment. Secondary goals were to determine factors associated with inadequate empirical therapy and to assess its impact on mortality and length of stay. METHODS: All patients with an E. coli bacteraemia hospitalized in 2008 were identified retrospectively. Initial antimicrobial therapy and clinical outcomes of all patients with an isolate resistant to gentamicin and/or ciprofloxacin (cases) were compared to those of a group of randomly selected patients in whom a gentamicin and ciprofloxacin susceptible E. coli was isolated (controls). RESULTS: One hundred and thirty-six unique patients had E. coli bacteraemia. Of these, 34 patients were identified as cases and were compared to 34 controls. Among the cases, 97% of the E. coli was resistant to ciprofloxacin and 44% to gentamicin. Resistance to amoxicillin was high in both cases (94%) and controls (65%). In 41% of the cases initial antimicrobial therapy was inadequate, compared to only 3% in the controls. The majority of inadequately treated cases had a biliary focus (64%). Infections in cases were more often healthcare-associated than infections in controls (62% vs 26%). E. coli with the same resistance pattern had been isolated before in adequately treated cases more often than in inadequately treated cases. Mortality did not differ significantly between cases and controls. CONCLUSIONS: Neither ciprofloxacin nor amoxicillin should be used as empirical therapy in patients with a presumed E. coli bacteraemia.

The prevalence of persistent bacteraemia in patients with a non-staphylococcal infective endocarditis, a retrospective cohort study.

BACKGROUND: Current guidelines on the management of infective endocarditis (IE) recommend follow-up blood cultures (FUBCs) to identify persistent bacteraemia, as this has prognostic value and guides treatment decisions. While persistent bacteraemia frequently occurs in Staphylococcus aureus bacteraemia and IE, its prevalence and impact in non-staphylococcal IE is largely unknown. We determined prevalence and prognostic value of persistent bacteraemia in non-staphylococcal IE. METHODS: We conducted a retrospective analysis of all patients diagnosed with definite non-staphylococcal endocarditis according to the modified Duke Criteria in two university hospital endocarditis registries We determined the prevalence and prognostic value of persistent bacteraemia. RESULTS: Of the included 159 patients 70 (44%) had prosthetic valve endocarditis (PVE). A median number of two [IQR 1-3] FUBCs were taken during the first week, with 134/159 (84%) having at least one FUBC in the first four days. Seven patients (4,4%) had persistent bacteraemia 48 h after start of antibiotic treatment: 5/70 patients (7.1%) with PVE and 2/89 (2.2%) with native valve endocarditis. Among 97 patients with streptococcal IE, nine patients with HACEK IE and six patients with Cutibacterium IE, no persistent bacteraemia was observed. Enterococcus faecalis was the causative microorganism in five patients with persistent bacteraemia, the other two had non-HACEK Gram-negative endocarditis. CONCLUSION: Persistent bacteraemia in non-staphylococcal endocarditis was rare. It was more frequently observed in PVE and was restricted to more resilient microorganisms such as enterococci and non-HACEK Gram-negative bacteria. Routine collection of FUBCs in patients with streptococcal endocarditis has a low yield and may require re-evaluation.

All-Cause and Infection-Related Mortality in Staphylococcus aureus Bacteremia, a Multicenter Prospective Cohort Study.

Background: Staphylococcus aureus bacteremia (SAB) is a heterogeneous disease with changing epidemiology due to changing demographics and evolving clinical management. SAB is associated with high mortality, but the current fraction of infection-related mortality is less well quantified. Methods: In a multicenter prospective cohort study of consecutive patients with SAB, we determined clinical features of SAB and determined 90-day mortality and risk factors of all-cause and infection-related mortality. Infection-related mortality was based on an adjudication committee evaluation. Results: Four hundred ninety patients with SAB were included, with community-acquired (n = 166), health care-associated (n = 163), and hospital-acquired SAB (n = 161). Endocarditis (n = 90, 18.3%), peripheral intravenous catheter infection (n = 80, 16.3%), and septic arthritis (n = 58, 11.8%) were the most frequent diagnoses, but proportions differed for community, health care, and hospital acquisition. One hundred ninety-two patients (39%) had permanent implanted prosthetic material (eg, prosthetic joint, heart valve, pacemaker). Day 90 all-cause mortality was 33% (n = 161), with 60% adjudicated as infection-related, and 90% of infection-related deaths occurring in the first 30 days post-SAB. Infection-related deaths after 30 days were rare and mainly related to endocarditis. Determinants associated with day 90 infection-related mortality were age (odds ratio [OR], 1.09; 95% CI, 1.06-1.11), Charlson comorbidity index (OR, 1.13; 95% CI, 1.01-1.26), septic shock (OR, 9.78; 95% CI, 4.56-20.95), endocarditis (OR, 3.4; 95% CI, 1.75-6.61), and persistent SAB at 48 hours (OR, 2.36; 95% CI, 1.27-4.37). Conclusions: Mortality due to S. aureus infection remains high and mainly occurs in the first 30 days, which could guide end points in future studies.