Uncomplicated Bloodstream Infections Research Articles

Intravenous versus Partial Oral Antibiotic Therapy in the Treatment of Uncomplicated Bloodstream Infection Due to Streptococcus Species.

This retrospective cohort study examines effectiveness of partial oral antibiotic regimens in uncomplicated bloodstream infections (BSIs) due to Streptococcus species compared to standard intravenous therapy. Adult patients with uncomplicated streptococcal BSIs from April 2016 to June 2020 in seven hospitals in South Carolina, USA, were evaluated. Multivariate Cox proportional hazards regression was used to examine the time to treatment failure within 90 days of a BSI after adjustment for the propensity to receive partial oral therapy. Multivariate linear regression was used to examine the hospital length of stay (HLOS). Among the 222 patients included, 99 received standard intravenous antibiotics and 123 received partial oral therapy. Of the standard intravenous therapy group, 46/99 (46.5%) required outpatient parenteral antibiotic therapy (OPAT). There was no difference in the risk of treatment failure between partial oral and standard intravenous therapy (hazards ratio 0.53, 95% CI 0.18, 1.60; p = 0.25). Partial oral therapy was independently associated with a shorter HLOS after adjustments for the propensity to receive partial oral therapy and other potential confounders (-2.23 days, 95% CI -3.53, -0.94; p < 0.001). Transitioning patients to oral antibiotics may be a reasonable strategy in the management of uncomplicated streptococcal BSIs. Partial oral therapy does not seem to have a higher risk of treatment failure and may spare patients from prolonged hospitalizations and OPAT complications.

1843. Intravenous versus Partial Oral Antibiotic Therapy in the Treatment of Uncomplicated Bloodstream Infection due to Streptococcus species

Abstract Background Effectiveness of oral antibiotics for transition of therapy in uncomplicated bloodstream infections (BSI) due to Streptococcus species remains unclear. This retrospective cohort study examines effectiveness of partial oral antibiotic regimens in patients with uncomplicated BSI due to Streptococcus species compared to standard intravenous (IV) only therapy. Methods Adult patients with uncomplicated BSI due to Streptococcus species from April 2016 through June 2020 in 7 hospitals within Prisma Health in South Carolina were evaluated. Patients who died within 7 days of BSI were excluded to reduce the impact of survival bias. Multivariate Cox proportional hazards regression was used to examine time to treatment failure, defined as a composite of all-cause mortality and BSI recurrence within 90 days. Results A total of 222 patients with Streptococcus species BSI were included in the analysis. Overall, the median age was 62 years, and 116 (52.3%) were men. Beta-hemolytic streptococci (87; 39.2%) were the most common bloodstream isolates, followed by S. pneumoniae (76; 34.2%) and viridans group streptococci (59; 26.6%). Among this cohort, 99 patients received only IV antibiotics, and the remaining 123 received partial oral therapy. The median duration of therapy in both groups was 14 days, and median duration of IV antibiotics prior to oral transition was 4 days. Most patients in the partial oral group were transitioned to either oral beta-lactams (62; 50.4%) or fluoroquinolones (47; 38.2%). Of the IV only group, 46 (46.5%) required outpatient IV antibiotics. Treatment failure rates were 12.0% and 4.4% in the IV only and partial oral therapy groups, respectively (p=0.04). After adjustments for age, chronic comorbidities, and initial response to therapy within the first 72-96 hours, there was no difference in the risk of treatment failure in the partial oral compared to IV only group (hazards ratio 0.55, 95% CI 0.19-1.64; p=0.28). Conclusion Transitioning patients from IV to oral antibiotics may be a reasonable strategy in the management of uncomplicated BSI due to Streptococcus species. Partial oral therapy does not seem to have a higher treatment failure rate than standard IV only therapy and may spare many patients from outpatient IV antibiotics. Disclosures All Authors: No reported disclosures.

Behandlung von Staphylococcus-aureus-Blutstrominfektionen

Staphylococcus aureus bloodstream infections (SAB) represent a distinct clinical entity. Due to the frequency and the associated high morbidity and mortality, special requirements apply to the clinical management. Thus, in contrast to coagulase-negative staphylococci, even the detection of S. aureus in a single blood culture bottle is considered to be an infection requiring treatment. A classification into complicated versus uncomplicated bloodstream infections is carried out, with implications for the recommended duration of treatment (2 vs. 4–6 weeks). The use of transesophageal echocardiography to exclude endocarditis is indicated in the vast majority of cases. Because of frequent clinically silent septic metastases, positron emission tomography with computed tomography (PET-CT) is a useful tool for detection of nidi. For methicillin-sensitive S. aureus (MSSA), flucloxacillin and cefazolin are applied as basic treatment and for methicillin-resistant S. aureus (MRSA), vancomycin or daptomycin are used depending on the focus and comorbidity. If foreign material is present, a combination of basic treatment with rifampicin or fosfomycin should be considered. Source control by abscess drainage or removal of infected intravascular catheters, intracardiac devices or if necessary artificial joints is important. Studies show that infectious disease consultations improve the quality of care and mortality in SAB. Current open questions address the identification of subpopulations that benefit from combination treatment, the effectiveness and timing of stepdown oral antibiotic treatment, and a possible reduction in the overall duration of treatment. This review article summarizes the current standards for diagnostics and treatment of patients with SAB and presents recent relevant studies on this condition.

Antimicrobial treatment duration for uncomplicated bloodstream infections in critically ill children: a multicentre observational study

BackgroundBloodstream infections (BSIs) cause significant morbidity and mortality in critically ill children but treatment duration is understudied. We describe the durations of antimicrobial treatment that critically ill children receive and explore factors associated with treatment duration.MethodsWe conducted a retrospective observational cohort study in six pediatric intensive care units (PICUs) across Canada. Associations between treatment duration and patient-, infection- and pathogen-related characteristics were explored using multivariable regression analyses.ResultsAmong 187 critically ill children with BSIs, the median duration of antimicrobial treatment was 15 (IQR 11–25) days. Median treatment durations were longer than two weeks for all subjects with known sources of infection: catheter-related 16 (IQR 11–24), respiratory 15 (IQR 11–26), intra-abdominal 20 (IQR 14–26), skin/soft tissue 17 (IQR 15–33), urinary 17 (IQR 15–35), central nervous system 33 (IQR 15–46) and other sources 29.5 (IQR 15–55) days. When sources of infection were unclear, the median duration was 13 (IQR 10–16) days. Treatment durations varied widely within and across PICUs. In multivariable linear regression, longer treatment durations were associated with severity of illness (+ 0.4 days longer [95% confidence interval (CI), 0.1 to 0.7, p = 0.007] per unit increase in PRISM-IV) and central nervous system infection (+ 17 days [95% CI, 6.7 to 27.4], p = 0.001). Age and pathogen type were not associated with treatment duration.ConclusionsMost critically ill children with BSIs received at least two weeks of antimicrobial treatment. Further study is needed to determine whether shorter duration therapy would be effective for selected critically ill children.

289. Impact of Clinician Specialty on the Use of Oral Antibiotic Therapy for Definitive Treatment of Uncomplicated Bloodstream Infections

BackgroundNo established guidelines exist regarding the role of oral antibiotic therapy (OAT) to treat uncomplicated bloodstream infections (uBSIs) and practices may vary depending on clinician specialty and experience.MethodsAn IRB-exempt web-based survey was emailed to Nebraska Medicine clinicians caring for hospitalized patients, and widely disseminated using social media. The survey was open access and once disseminated on social media, it was impossible to ascertain the total number of individuals who received the survey. Chi-squared analysis for categorical data was conducted to evaluate the association between responses and demographic groups.ResultsOf 275 survey responses, 51% were via social media, and 94% originated in the United States. Two-thirds of respondents were physicians, 16% pharmacists, and infectious diseases clinicians (IDC) represented 71% of respondents. The syndromes where most were comfortable using OAT routinely for uBSI were urinary tract infection (92%), pneumonia (82%), pyelonephritis (82%), and skin/soft tissue infections (69%). IDC were more comfortable routinely using OAT to treat uBSIs associated with vertebral osteomyelitis and prosthetic joint infections than non-infectious diseases clinicians (NIDC), but NIDC were more likely to report comfort with routine use of OAT to treat uBSIs associated with meningitis and skin/soft tissue infections. IDC were more likely to report comfort with routine use of OAT for uBSIs due to Enterobacteriaceae and gram-positive anaerobes, while NIDC were more likely to be comfortable with routinely using OAT to treat uBSIs associated with S. aureus, coagulase-negative staphylococci and gram-positive bacilli. In one clinical vignette of S. aureus uBSI due to debrided abscess, 11% of IDC would be comfortable using OAT vs 28% of NIDC; IDC were more likely to report routinely repeating blood cultures (99% vs 83%, p< 0.05).Figure 1: Clinician comfort using oral antibiotic therapy to treat uncomplicated bacteremia due to specific syndromes Figure 2: Clinician comfort using oral antibiotic therapy to treat uncomplicated bacteremia due to specific organisms ConclusionConsiderable variation in comfort using OAT for uBSIs among IDC vs NIDC exists, highlighting opportunities for IDC to continue to demonstrate their value in clinical practice. Understanding the reasons for variability may be helpful in creating best practice guidelines to standardize decision making.Disclosures All Authors: No reported disclosures

Sustained Circulating Bacterial Deoxyribonucleic Acid Is Associated With Complicated Staphylococcus aureus Bacteremia.

Background Staphylococcus aureus (SA) bacteremia often requires a long treatment duration with antibiotics to prevent relapse due to the ability of SA to establish reservoirs of infection in sites such as heart and bone. These metastatic sites of infection cannot be serially sampled to monitor the clearance of SA infection. This study aimed to establish a link between persistence of circulating SA deoxyribonucleic acid (SA-DNA) and tissue reservoirs in patients with SA bacteremia.MethodsA highly sensitive quantitative polymerase chain reaction was used to measure whole blood SA-DNA and plasma-derived SA cell-free DNA (SA-cfDNA) in a set of longitudinal samples from 73 patients with confirmed SA bacteremia and correlated with clinical features.ResultsBlood SA-DNA was detected for longer than the duration of positive blood cultures. Longer duration of circulating bacterial DNA was observed in complicated SA bacteremia infections, such as endocarditis and osteoarticular infections, compared with uncomplicated bloodstream infections. In contrast, traditional blood cultures demonstrated similar time to clearance regardless of foci of infection. Plasma-derived SA-cfDNA showed concordance with blood SA-DNA levels. Baseline levels of SA-DNA were higher in patients presenting with greater clinical severity and complicated bacteremia.ConclusionsProlonged levels of circulating SA-DNA in patients with complicated tissue reservoirs after clearance of blood cultures observed in this single-center study should be validated in additional cohorts to assess the potential utility for monitoring clearance of infection in patients with SA bacteremia.

The Value of Combining Blood Culture and SeptiFast Data for Predicting Complicated Bloodstream Infections Caused by Gram-Positive Bacteria or Candida Species

Management of complicated bloodstream infections requires more aggressive treatment than uncomplicated bloodstream infections. We assessed the value of follow-up blood culture in bloodstream infections caused by Staphylococcus aureus, Enterococcus spp., Streptococcus spp., and Candida spp. and studied the value of persistence of DNA in blood (using SeptiFast) for predicting complicated bloodstream infections. Patients with bloodstream infections caused by these microorganisms were enrolled prospectively. After the first positive blood culture, samples were obtained every third day to perform blood culture and SeptiFast analyses simultaneously. Patients were followed to detect complicated bloodstream infection. The study sample comprised 119 patients. One-third of the patients developed complicated bloodstream infections. The values of persistently positive tests to predict complicated bloodstream infections were as follows: SeptiFast positive samples (sensitivity, 56%; specificity, 79.5%; positive predictive value, 54%; negative predictive value, 80.5%; accuracy, 72.3%) and positive blood cultures (sensitivity, 30.5%; specificity, 92.8%; positive predictive value, 64%; negative predictive value, 75.5%; accuracy, 73.9%). Multivariate analysis showed that patients with a positive SeptiFast result between days 3 and 7 had an almost 8-fold-higher risk of developing a complicated bloodstream infection. In S. aureus, the combination of both techniques to exclude endovascular complications was significantly better than the use of blood culture alone. We obtained a score with variables selected by the multivariate model. With a cutoff of 7, the negative predictive value for complicated bloodstream infection was 96.6%. Patients with a positive SeptiFast result between days 3 and 7 after a positive blood culture have an almost 8-fold-higher risk of developing complicated bloodstream infections. A score combining clinical data with the SeptiFast result may improve the exclusion of complicated bloodstream infections.

Clinical Consensus Conference: Survey on Gram‐Positive Bloodstream Infections with a Focus onStaphylococcus aureus

The increased incidence over the past decade of bloodstream infections (BSIs) caused by gram-positive bacteria, particularly methicillin-resistant Staphylococcus aureus, highlights the critical need for a consistent approach to therapy. However, there is currently no international consensus on the diagnosis and management of gram-positive BSIs. The Clinical Consensus Conference on Gram-Positive Bloodstream Infections was convened as a session at the 9th International Symposium on Modern Concepts in Endocarditis and Cardiovascular Infections held in 2007. Participants discussed various aspects of the practical treatment of patients who present with gram-positive BSI, including therapeutic options for patients with BSIs of undefined origin, the selection of appropriate empirical therapy, and treatment of complicated and uncomplicated BSIs. The opinions of participants about these key issues are reflected in this article.