Blood Culture Contamination Research Articles

114. Prospective Trial of Passive Diversion Device to Reduce Blood Culture Contamination

BackgroundBlood culture contaminants can lead to inappropriate antibiotic use, prolonged length of stay, and additional hospital costs. Several devices have been developed to reduce the risk of blood culture contamination by diverting a portion of the initial blood sample from the blood culture bottle. We have assessed the effectiveness of one blood diversion device in a prospective trial performed at the two separate emergency departments (EDs) of a three-campus Academic Medical Center.MethodsA multi-phase prospective crossover trial was performed with the blood diversion device initially in use at one ED (Memorial) and standard equipment at the other ED (University) for 10 weeks. After a washout phase, a second 10-week study phase used the blood diversion device in the other ED (University) and standard equipment at the first ED (Memorial). Contaminants were identified by the clinical microbiology lab using standard criteria, and further defined by independent retrospective review by 3 infectious disease physicians prior to statistical analysis. An intention-to-treat analysis was performed, and Chi-square tests were used to compare contaminant rates among samples obtained using the blood diversion device versus standard equipment.Results5,675 blood samples were obtained with 5,661 samples analyzed after 14 were deemed inconclusive by the ID physician review. There were 1,719 samples obtained at Memorial ED and 3,942 at University ED, with 2,836 samples collected during diversion device periods and 2,825 during standard equipment periods. Based on the ID physician review, the contaminant rates were 1.9% in diversion device periods versus 2.9% in standard equipment periods (P = 0.018). There was a marked difference in blood culture contamination rates between the two EDs with contaminant rates at the Memorial ED of 1.1% and 1.4% (P=0.57), and at the University ED of 2.3% and 3.5% (P=0.024) for the diversion device and standard equipment periods, respectively.ConclusionThe blood diversion device was able to significantly lower blood culture contamination rates overall by 1% at the institution’s two EDs (34% relative reduction), with a stronger effect noted at the campus with both a level 1 trauma center and transplant programs. Disclosures All Authors: No reported disclosures

660. Effect of the COVID-19 Pandemic on Blood Culture Contamination Rates and Quality Improvement Processes

BackgroundBlood cultures are the gold standard for diagnosing bloodstream infections and a vital part of the work-up in systemic infections. However, contamination of blood cultures represents a significant burden on patients and the healthcare system with increased hospital length of stay, unnecessary antibiotics, and financial cost. The data discussed here offer insight into blood culture contamination rates before and through the COVID-19 pandemic at a community hospital and the processes that were affected by the pandemic.MethodsBlood culture contaminations were determined by using the number of sets of blood cultures with growth and the presence of an organism from the National Healthcare Safety Network's (NHSN) commensal organism. Contamination rates were evaluated by status as a standard unit or a COVID-19 isolation unit in either the emergency department (ED) or inpatient floor units. The identified four groups had different processes for drawing blood cultures, particularly in terms of training of staff in use of diversion devices. The electronic medical record was used to track contaminations and the use of diversion devices in the different units.ResultsThe inpatient COVID units were consistently elevated above the other units and the institutional contaminant goal of 2.25%, ranging from 9.6% to 13.3% from 4/2020-9/2020. Those units were the primary driver of the increase in overall contamination rates. COVID ED nursing staff (that had previously undergone training in the use of diversion devices) used diversion devices to draw 51 of 133 (38.3%) cultures compared to only 15 of 84 (17.9%) on the COVID inpatient units. Figure 1. Comparison of contamination rates in the ED vs the inpatient units from all campuses from September 2019 through September 2020. The blue line represents the hospital goal of 2.25% contamination rate. Solid lines represent total contamination rates including COVID isolation units whereas dotted lines represent units excluding COVID isolation units. Figure 2. Comparison of the non-COVID vs COVID isolation units in the emergency department and inpatient units. The red line represents the hospital goal of less than 2.25% for blood culture contamination rate.Table of Contaminants vs. Total Collected Blood Cultures in Each Unit by Month Figure 3. Raw data from Figure 2. Total blood culture contaminations from each unit by month compared to total blood culture collections from each unit by month.ConclusionEvaluation revealed that nursing staff with less training in blood culture collection, particularly the use of diversion devices, were the primary staff collecting blood cultures in the inpatient COVID units. The difference in training is felt to be the primary driver of the increase in contaminants in the inpatient COVID units. The marked increase in contaminations highlights the difficulties of maintaining quality control processes during an evolving pandemic and the importance of ongoing efforts to improve the quality of care. These findings demonstrate the importance of training and routine use of procedures to reduce contaminations even during.Disclosures All Authors: No reported disclosures

641. Clinical Predictors of Hospital-Acquired Bloodstream Infections

BackgroundHospital-acquired bloodstream infections (HABSI) are associated with increased mortality and decreased hospital quality metrics. This has led to an increased focus on blood culture stewardship. Little data exists regarding predictive factors of bacteremia in hospitalized patients. We aim to determine what clinical characteristics in patients were predictive of HABSI.MethodsThis is a retrospective case-control study of 540 patients with positive blood cultures admitted to our health system between September 1, 2017, to April 1, 2020. Electronic medical records of patients with positive blood cultures were independently reviewed to determine contamination versus true bacteremia. We looked at different clinical parameters and laboratory investigations within 24 hours of drawing blood cultures. Clinical variables were age ≥ 60 years, heart rate ≥ 90/minute, systolic blood pressure ≤ 90 mmHg or use of a vasopressor, oral temperature > 38°Celsius (100.4°Fahrenheit), white blood cells (WBC) count ≥12,000/µL, lymphocytes ≤ 1000/mm3, platelets < 150,000 /µL, and creatinine >2.0 mg/dL. Stepwise logistic regression analysis was used for predictive statistical model development.ResultsIn a cohort of 481 patients with hospital-acquired bacteremia, 350 cases had true bacteremia and 131 cases were contaminated blood cultures. Stepwise regression analysis showed that white blood cell (WBC) count ≥ 12,000 cells/µL, lymphocyte count ≤ 1000/mm3, creatinine > 2.0 mg/dL, and oral temperature > 38°C (100.4°F) were associated with HABSI (R-square= 0.06, p value= 0.002).ConclusionOur findings suggest that WBC count, lymphocyte count, creatinine, and oral temperature together can be used to develop appropriate blood culture stewardship models in the inpatient setting. This may help minimize unnecessary blood cultures.Disclosures All Authors: No reported disclosures

81. Reducing Unnecessary Blood Cultures Through Diagnostic Stewardship

BackgroundAt our institution, we learned the frequency of blood cultures was sometimes being changed from “Once” to “Daily” without a defined number of days. We hypothesized this led to unnecessary blood cultures being performed.MethodsOver a 3 month period from 12/6/2019-3/6/2020, we retrospectively evaluated the charts of patients who had a blood culture frequency changed to “Daily”. We evaluated if there was an initial positive blood culture within 48 hours of the “Daily” order being placed and the number of positive, negative, or “contaminant” sets of cultures drawn with the order. Contaminant blood cultures were defined as a contaminant species, present only once in the repeat cultures, and not present in initial positive cultures.Results95 unique orders were placed with 406 sets of cultures drawn from 89 adults. ~20% of the time (17 orders) the order was placed without an initial positive blood culture. This led to 62 sets of cultures being drawn, only 1 of which came back positive. 78/95 orders had an initial positive blood culture. The most common initial organisms were Staphylococcus aureus (SA) (38), Candida sp (10), Enterobacterales sp (10), and coagulase negative staphylococci (7). 43/78 (55%) orders with an initial positive set had positive repeat cultures. SA (26) and Candida sp (8) were most common to have positive repeats. Central line associated bloodstream infections (CLABSI) were found in 5 of the orders and contaminant species were found in 4 of the orders. 54% of the patients who had a “Daily” order placed did not have positive repeat cultures. The majority of the cultures were drawn from Surgical (40 orders) and Medical (35 orders) services. Assuming that SA and Candida sp require 48 hours of negative blood cultures to document clearance and other species require 24 hours, it was estimated that 51% of the cultures drawn using the "Daily" frequency were unnecessary. Cost savings over a year of removing the "Daily" frequency would be ~&14,000. Data from "Daily" blood culture orders drawn at Oregon Health & Science University from 12/6/2019-3/6/2020ConclusionUnnecessary blood cultures are drawn when the frequency of blood cultures is changed to "Daily". Repeat blood cultures had the greatest utility in bloodstream infections due to SA or Candida sp, and with CLABSI where the line is still in place. These results led to a stewardship intervention to change blood culture ordering at our institution.Disclosures All Authors: No reported disclosures

1027. Earlier Is Better: Progress Toward Decreased Time to Optimal Therapy and Improved Antibiotic Stewardship for Gram-positive Bloodstream Infections Through Use of GenMark Dx ePlex system

BackgroundThe ePlex BCID Gram-Positive (GP) panel utilizes electrowetting technology to detect the most common causes of GP bacteremia (20 targets) and 4 antimicrobial resistance (AMR) genes in positive blood culture (BC) bottles. Rapid detection of intrinsic vancomycin resistance and acquired resistance genes (mecA, mecC, vanA, vanB) enables early optimization of antimicrobial therapy whereas early detection of common contaminants is expected to decrease unnecessary antibiotic utilization and hospitalizations.MethodsIn this prospective study, aliquots of BC bottles with GP bacteria detected on Gram stain (GS) (n=101) received standard of care (SOC) culture and antimicrobial susceptibility testing (AST). Additionally, samples were evaluated with the BCID-GP panel but only SOC results were reported in the EMR and available to inform clinical decisions. Patients were excluded if the sample was a subsequent culture in a persistent episode of bacteremia (n=17) or if the assay failed (n=4). Chart review was performed to evaluate the expected impact of the BCID-GP panel on the time to organism identification, AST results, and optimization of antimicrobial therapy. ResultsA total of 80 patients were included in the final analysis (Table 1). S. epidermidis was the most common bacteria identified, followed by S. aureus, and other coagulase-negative staphylococci. Thirty-nine patients with staphylococci (48.8%) had the mecA gene detected and 2 patients with E. faecium had the vanA gene detected. The BCID-GP panel saved a mean of 24.4 hours (h) to identification and 48.3h to susceptibility testing compared to standard methods across all patients. In 38 patients (47.5%), the BCID-GP panel result could have enabled an earlier change in antibiotic therapy. Table 2 highlights opportunities to optimize antimicrobial therapy 53.4h earlier for 16 (20%) patients with organisms expressing AMR genes, 29.2h earlier for 8 (10%) patients infected with organisms, such as streptococci, with very low resistance rates, and to stop antimicrobial therapy 42.9h earlier for 14 (17.5%) patients with contaminated blood cultures. ConclusionThe BCID-GP panel could have enabled earlier optimization or stopping of antibiotics in many patients with significant time savings compared to standard laboratory methods. Disclosures Todd P. McCarty, MD, Cidara (Grant/Research Support)GenMark (Grant/Research Support, Other Financial or Material Support, Honoraria for Research Presentation)T2 Biosystems (Consultant) Sixto M. Leal, Jr., MD, PhD, Abnova (Grant/Research Support)AltImmune (Grant/Research Support)Amplyx Pharmaceuticals (Grant/Research Support)Astellas Pharmaceuticals (Grant/Research Support)CNINE Dx (Grant/Research Support)GenMark Diagnostics (Grant/Research Support, Other Financial or Material Support, Honoraria- Research Presentation)IHMA (Grant/Research Support)IMMY Dx (Grant/Research Support)JMI/Sentry (Grant/Research Support)mFluiDx Dx (Grant/Research Support)SpeeDx Dx (Grant/Research Support)Tetraphase Pharmaceuticals (Grant/Research Support)

SURVEYING THE RATE OF CONFIDENTIAL BLOOD TRANSPORTATION AND SOLUTIONS TO ENHANCE THE QUALITY OF BLOOD TREATMENT AT THE CENTER FOR TROPICAL DISEASES OF NGHE AN FRIENDSHIP GENERAL HOSPITAL

Background: Contamination in blood cultures is a challenge to identify causative agents of infections. Which may complicate clinical indications, or prolong the time of diagnosis, and affect treatment outcomes.Objectives: To determine the rate of contamination in blood cultures, and implement some interventions to improve the quality of blood cultures, to reduce proportion of blood cultures contamination below 3%.Subjects and methodology: All Blood cultures of patients who were treated at the Center for Tropical Diseases, Nghe An Friendship General Hospital from October 2020 to March 2021.Cross - sectional descriptive study. &#x0D; Results: There were 1756 cultured blood samples; from October to December 2020: 894 samples, from March 1, 2021: 862 samples. Rate of positive culture was 25.7%, of which true positive 12.9%, contamination: 12.8%, true negative: 74.3%. Contamination before training was 16.1%, and decreased to 9.4%after training. Coagulase - negative Staphylococci bacteria caused 63.2% contamination,accounted higher proportion than Gram - positive bacilli as 21.2%.Recommendation: We could not eliminate blood cultures contamination, but we could reduce the amount of contamination. Training in awareness and practice greatly reduces the prevalence of blood cultures contamination.

Effect of the introduction of a management bundle for blood culture collection

BackgroundInappropriate blood collection subjected to blood culture (BC) causes BC contamination and may complicate the diagnose is of infectious diseases. Therefore, we developed a bundle based on the guideline recommendations for appropriate blood collection and examined the effects of bundle introduction. MethodsWe performed a retrospective analysis of BC samples to determine the contamination rates before and after introducing the BC bundle. We also analyzed the correlation between the compliance rate of the bundle and contamination rate, and between each bundle element and contamination. ResultsAfter the introduction of the bundle, the contamination rate was significantly reduced from 5.4% ± 0.9% to 1.7± 0.7% (P < .01). The compliance rate of the bundle was significantly associated with a lower contamination rate (P < .01). Multivariable logistic regression showed that collection from superficial veins of the cubital fossa (odds ratio [OR], 0.25; 95% confidence interval [CI], 0.13-0.51, P < .01) and disinfection of the skin at the blood collection site with 1% chlorhexidine alcohol swab (OR, 0.41; 95% CI, 0.25-0.68, P < .01) were significantly associated with lower contamination. ConclusionsThis study suggests that the introduction of the BC bundle significantly reduced the contamination rate, and bundle compliance was associated with a lower contamination rate.

The effect of the COVID-19 pandemic on the epidemiology of positive blood cultures in Swiss intensive care units: a nationwide surveillance study

BackgroundEvidence about the impact of the pandemic of COVID-19 on the incidence rates of blood cultures contaminations and bloodstream infections in intensive care units (ICUs) remains scant. The objective of this study was to investigate the nationwide epidemiology of positive blood cultures drawn in ICUs during the first two pandemic waves of COVID-19 in Switzerland.MethodsWe analyzed data on positive blood cultures among ICU patients, prospectively collected through a nationwide surveillance system (ANRESIS), from March 30, 2020, to May 31, 2021, a 14-month timeframe that included a first wave of COVID-19, which affected the French and Italian-speaking regions, an interim period (summer 2020) and a second wave that affected the entire country. We used the number of ICU patient-days provided by the Swiss Federal Office of Public Health as denominator to calculate incidence rates of blood culture contaminations and bloodstream infections (ICU-BSI). Incidence rate ratios comparing the interim period with the second wave were determined by segmented Poisson regression models.ResultsA total of 1099 blood culture contaminations and 1616 ICU-BSIs were identified in 52 ICUs during the study. Overall, more episodes of blood culture contaminations and ICU-BSI were observed during the pandemic waves, compared to the interim period. The proportions of blood culture contaminations and ICU-BSI were positively associated with the ICU occupancy rate, which was higher during the COVID-19 waves. During the more representative second wave (versus interim period), we observed an increased incidence of blood culture contaminations (IRR 1.57, 95% CI 1.16–2.12) and ICU-BSI (IRR 1.20, 95% CI 1.03–1.39).ConclusionsAn increase in blood culture contaminations and ICU-BSIs was observed during the second COVID-19 pandemic wave, especially in months when the ICU burden of COVID-19 patients was high.

Analysis of Blood Culture Data Influences Future Epidemiology of Bloodstream Infections: A 5-year Retrospective Study at a Tertiary Care Hospital in India

ABSTRACTBackgroundBlood cultures are the most significant samples received in a microbiology laboratory. Good quality control of pre-analytic, analytic, and post-analytic stages can have a significant impact on patient outcomes. Here, we present the improvements brought about by reviewing blood culture data with clinicians at a tertiary care institute in India.MethodsFour-year blood culture data (phase I—February 2014–February 2018) were shared with clinicians in the clinical grand round. Several take-home messages were discussed in a quiz format, and a number of holistic quality control measures were implemented at different levels. Based on observable changes in blood culture reports, another dataset was analyzed and compared in phase II (April 2018–April 2019).ResultsIn phase II, the blood culture contamination rate improved from 6 to 2% along with four times reduction in ICU isolates and three times increased isolation of salmonellae and pneumococci. The development of resistance in Klebsiella pneumoniae to carbapenems and piperacillin–tazobactam was reduced. Colistin resistance in ICU isolates hovered around 15%. Vaccine-preventable pneumococcal serotypes were predominant in the under-five age-group. Typhoidal salmonellae were more commonly isolated from adults with 50% showing sensitivity to pefloxacin and 97% to ampicillin, chloramphenicol, and cotrimoxazole. Candida parapsilosis was the leading non-albicans Candida (NAC). Fluconazole resistance was observed in 50% of NAC.ConclusionReviewing blood culture data with clinicians mutually helped us to improve the overall quality of blood culture reports. It had a major impact on epidemiological trends and thus, found to be superior to just sharing an antibiogram with the clinicians.How to cite this articleSharma A, Samaddar A, Maurya A, Hada V, Narula H, Shrimali T, et al. Analysis of Blood Culture Data Influences Future Epidemiology of Bloodstream Infections: A 5-year Retrospective Study at a Tertiary Care Hospital in India. Indian J Crit Care Med 2021;25(11):1258–1262.

Initial Specimen Diversion Device® reduces blood culture contamination and vancomycin use in academic medical centre

In suspected bloodstream infections, accurate blood culture results are critical to timely diagnoses and appropriate antibiotic administration. An Initial Specimen Diversion Device®, Steripath® (Magnolia Medical Technologies, Seattle, WA, USA) was evaluated for efficacy in reducing blood culture contamination at Brooke Army Medical Center (6.8% six-month contamination rate prior to intervention) in a six-month quality improvement project. Blood cultures in the emergency department were collected using either Steripath or the standard method. Blood samples of 20 mL were cultured into an aerobic and anaerobic medium and incubated for five days using an automated microbial detection system immediately after collection. Positive bottles were Gram-stained and plated. Rapid molecular polymerase chain reaction identification was performed on all first positive bottles within a blood culture set for each admission or ED visit. Speciation was deduced during antimicrobial sensitivity testing using the Vitek-2 instrument. Seven out of 1016 (0.69%) contamination events occurred when using Steripath vs 53 out of 800 (6.6%) contamination events when using the standard method. Steripath use was associated with a 90% lower incidence of blood culture contamination vs the standard method. Post study, Steripath use was implemented as standard practice hospital-wide, and a retrospective data analysis attributed a 31.4% decrease in vancomycin days of therapy to Steripath adoption. Using Steripath significantly decreased blood culture contamination events for bacterial bloodstream infections compared to the standard method. Subsequent adoption of Steripath reduced overall vancomycin usage. With widescale implementation Steripath could bolster antibiotic stewardship, mitigating antibiotic resistance caused by unnecessary antibacterial treatments.

Impact of Direct From Blood Culture Identification of Pathogens Paired With Antimicrobial Stewardship Interventions in a Pediatric Hospital.

Identification of organisms directly from positive blood culture by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has the potential for improved clinical outcomes through earlier organism identification and shorter time to appropriate clinical intervention. The uses of this technology in pediatric patients and its impact in this patient population have not been well described. Direct from positive blood culture organism identification via MALDI-TOF was implemented in September 2019. A quality improvement project was performed to assess its impact on admissions for contaminant blood cultures and time to effective and optimal antimicrobials and clinical decision-making. A pre- and post-implementation retrospective review for consecutive September through February time periods, was conducted on patients with positive monomicrobial blood cultures. Statistics were evaluated using Mann-Whitney U and χ2 tests. One hundred nineteen patients with 131 unique blood cultures (65 in pre- and 66 in post-implementation) were identified. Time to identification was shorter, median 35.4 hours (IQR, 22.7-54.3) versus 42.3 hours (IQR, 36.5-49) in post- and pre-groups, respectively (p = 0.02). Patients were less likely to be admitted for a contaminated blood culture in the post-implementation, 26% versus 11% in the pre-implementation (p = 0.03) group. In patients treated for bacteremia, there was a shorter time to optimal therapy from Gram stain reporting in the post-implementation (median 42.7 hours [IQR, 27.2-72]) versus pre-implementation (median 60.8 hours [IQR, 42.9-80.6]) (p = 0.03). Direct from positive blood culture identification by MALDI-TOF decreased time to effective and optimal antimicrobials and decreased unnecessary admission in pediatric patients for contaminated blood cultures.

Clinical Nurse Specialist Practice: Impact on Emergency Department Blood Culture Contamination.

Blood culture collection is a common procedure performed in emergency departments. Rate of blood culture contamination is a metric that is tracked by organizations to ensure appropriate treatment for patients suspected of having bacteremia and ensure appropriate use of hospital resources. A team of nurses and technicians undertook a quality improvement project to decrease blood culture contamination rates in a suburban emergency department. The project included use of standardized blood culture collection kits, creation of a dedicated collection team, and implementation of a new blood culture collection device. Through this work, blood culture contamination rates decreased from greater than 3.0% to less than 1.5% consistently for nearly 24 months. Providing feedback and continued monitoring has made this quality improvement initiative a success for the department and the organization and has resulted in cost savings of nearly 2 million dollars.

Feedback on Feedback.

Contaminated blood cultures are a known cause of increased hospital cost, prolonged length of stay, and exposure to unnecessary antibiotics. In 2007, the Clinical and Laboratory Standards Institute adopted an acceptable benchmark of overall blood culture contamination rate of <3%.1 However, multiple research studies have revealed that rates vary between institutions and are frequently greater than this benchmark.2,3 In this issue of Hospital Pediatrics , Bram et al4 describe a multifaceted quality improvement (QI) initiative to reduce the percentage of contaminated blood cultures in a pediatric emergency department at a freestanding children’s hospital. The results were impressive. Rates of contaminated blood cultures decreased from 6.7% to 2.1% over a 16-month period. The authors also estimated significant cost savings due to the reduction of contaminated blood cultures and their sequelae. The tremendous reduction in contaminated blood cultures and the cost savings are compelling. The improvers are to be commended for performing a true patient-centered QI initiative, avoiding unnecessary venipunctures, antibiotics, emergency department visits, hospital admissions and prolonged length of stay, work-life disruption, and concern over a potentially severe infection in a child. Although recognition of this accomplishment is appropriate, the point of publishing QI reports is to describe the context and interventions with enough specificity to replicate successful projects (with adaptations in new contexts) or to avoid ineffective interventions on the basis of the learnings of previous improvers. This report provides several replicable strategies but also raises interesting questions about …

Use of a Sterile Collection Process to Reduce Contaminated Peripheral Blood Cultures.

Contaminated blood cultures pose a significant burden by subjecting children to unnecessary testing, procedures, and antibiotics and increasing health care costs. The aim of our quality improvement (QI) initiative was to decrease the percentage of contaminated peripheral blood cultures in our pediatric emergency department (ED) from an average of 6.7% to <3% over a 16-month period. The QI initiative was implemented in the pediatric ED of a tertiary care children's hospital. Interventions included change of the peripheral blood culture collection from a clean to a sterile process, nursing education, and individualized feedback. The primary outcome measure was the percentage of contaminated peripheral blood cultures. The process measure was the percentage of nurses who completed 75% to 100% of the steps of the sterile collection process, as measured by self-reporting in audit cards. The balancing measures were time from antibiotic ordering to time of administration and ED length of stay. We decreased the percentage of contaminated peripheral blood cultures threefold from a baseline (June 2, 2018, to December 31, 2018) of 6.7% to 2.1% during the intervention period (January 1, 2019, to April 30, 2020). Ninety-eight percent of nurses who completed audit cards reported performing 75% to 100% of the steps of the new sterile process. There was no significant difference in the average time from antibiotic ordering to antibiotic administration or ED length of stay between the baseline and intervention periods. Use of a sterile blood culture collection process, in addition to nursing education and individualized feedback, is an effective method to decrease peripheral blood culture contamination rates in a pediatric ED.

43 The Prevalence of Serious Bacterial Infections in Infants less than 90 Days with and without Features of a Viral Infection: A Retrospective Cohort Study

Abstract Primary Subject area Emergency Medicine - Paediatric Background Prior studies suggest the prevalence of serious bacterial infections (SBI) (i.e., urinary tract infection [UTI], bacteremia, or meningitis) is lower in infants with a viral infection compared to those with fever without a source (FWS) (2-3% vs. 10-15%). Objectives To determine the difference in proportion of SBI in infants with and without clinical features of a viral infection. Design/Methods A retrospective cohort study was done on a consecutive sample of infants ≤ 90 days seen at a pediatric ED over a 5-year period ending August 30, 2019. Eligible subjects had rectal temperatures ≥ 38°C, and had ≥ 1 screening test for SBI (urine, blood and/or cerebrospinal fluid cultures). Excluded were infants who received antibiotics in the past 7 days, had congenital anomalies, required intensive care, or were preterm. We defined a clinical viral infection as &amp;gt; 1 clinical features of a respiratory viral infection (new-onset sneezing, cough, rhinorrhea, or shortness of breath). UTI was defined as per American Academy of Pediatrics guidelines. Results We screened 7021 charts and 885 (12%) were eligible. Of these, 498 (56%) had a clinical viral infection and 387 (44%) did not. Blood and urine cultures were collected from 860 (97%) infants and 308 (35%) had a lumbar puncture. Overall, 84 (10%) infants had an SBI: 76 (9%) UTI, 6 (0.7%) isolated bacteremia, and 2 (0.2%) meningitis. Among those with clinical viral infection, 23 (5%) had SBI, compared to 61 (16%) without viral infection (risk difference [RD] 11%, 95% CI [7%, 15%]). Both cases of meningitis occurred in infants ≤28 days and without any viral symptoms. A logistic regression was done to ascertain the effects of clinical viral infection, known risk factors for sepsis, age ≤ 28 days, or a temperature ≥ 39°C on the likelihood of SBI. Of the 4 predictors, only clinical viral infection and the presence of known risk factors for sepsis were significantly associated with SBI (odds ratio [OR] 0.3, 95% CI [0.17, 0.48] and 2.5, 95% CI [1.4, 4.5], respectively). Proportions of contaminated blood culture and urine culture were 5% (95% CI [4%, 7%]) and 14% (95% CI [12%, 17%]), respectively. Conclusion SBI prevalence in infants without features of a viral infection on assessment is triple that of infants with viral symptoms. Contaminant blood and urine cultures are folds higher than true pathological cultures. Future research is needed to identify infants at low risk of SBI without invasive testing.

Blood Culture Contamination in a Community Hospital- less than 2% is achievable

Abstract Introduction/Objective Blood cultures are commonly obtained to evaluate the presence of bacteria or fungal infection in a patient’s bloodstream. The presence of living microorganisms circulating in the bloodstream is of substantial prognostic and diagnostic importance. A positive blood culture indicates a reason for the patient’s illness and provides the etiological agent for antimicrobial therapy. Collection of blood culture is an exact process that requires time, the proper order of draw, and following of correct protocol. The busy Emergency department that requires multiple demands for nurse’s time, turnover of staff, rushing from one task to another can result in the improper collection and false-positive blood cultures. The national benchmark is set at 3% by the American Society of Clinical Microbiology (ASM) and The Clinical and Laboratory Standard Institute (CLSI). False-positive blood culture results in increased length of stay and unnecessary antimicrobial therapy, resulting in an increased cost burden to the hospital of about $5000 per patient. Methods/Case Report At our 150-bed community hospital, 26 beds Emergency Department, we have come a long way in reduction of our blood culture contamination rates from upwards of 4% to less than 2%, far lower than the national benchmark. Results (if a Case Study enter NA) NA Conclusion There are multiple devices available from various manufacturers claiming to reduce blood culture contamination. These devices do reduce blood culture (BC) contamination but at an added cost of the device. The rate of BC can be reduced and less than 3% is achievable by materials available in the laboratory. We have achieved this by providing training to every new staff by demonstration and direct observation, providing everything required for collection in a kit, using proper technique, the inclusion of diversion method that involves the aseptic collection of a clear tube before collecting blood cultures, and following up monthly on any false positive blood cultures.

Bacillus cereus Bacteremia: An Unusual Case Following Food Poisoning

Abstract Introduction/Objective Bacillus cereus is a spore-forming, gram-positive rod, well known for causing food poisoning. In addition, this bacterium often presents as a contaminant of blood cultures. Differentiating true bacteremia from contamination of blood samples is important as it has treatment implications. Early recognition is necessary, as it can cause septic shock if untreated. We present a challenging case of food poisoning with concomitant bacteremia in a young patient with a history of diabetes mellitus (DM), celiac disease, and new-onset chronic kidney disease (CKD). Methods/Case Report A 23-year-old adult male with a history of DM, new-onset CKD, and celiac disease presented with nausea, intermittent vomiting, and lower abdominal pain for 2 weeks. On initial evaluation, he had normal blood pressure but tachypnea and tachycardia. Physical examination was significant for left lower quadrant and flank tenderness. The symptoms were persistent and progressed to point that he could not tolerate meals due to vomiting. Two weeks earlier, he presented with similar complaints along with dysuria and was treated for suspected urinary tract infection with Co-trimoxazole. This time, further workup revealed normal white blood cell count (11.8 k/µL) with 81% neutrophils, elevated creatinine (3.56 mg/dL), blood urea nitrogen (49 mg/dL), and procalcitonin (0.39 ng/mL), with abnormal urinalysis showing increased turbidity, pyuria, and nitrituria. He was started on ceftriaxone, fluids, antiemetics and was admitted to the hospital for further management. The urine culture had no bacterial growth. Two sets of peripheral blood cultures (different sites at different times) had gram-positive rods which eventually turned out to be B. cereus, identified by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). Levofloxacin was started, and he reported improvement in nausea and vomiting by the next day of admission and was discharged. Results (if a Case Study enter NA) NA Conclusion Differentiating true B. cereus bacteremia from blood sample contamination is important. Additionally, no symptoms are specific for B. cereus-associated food poisoning, and the presence of risk factors doesn’t always favor this entity over other entities, hence adding difficulty to the diagnosis. A high index of suspicion is needed, as early intervention can prevent the development of life-threatening complications.

Regression discontinuity of blood culture contamination rate after changing of disinfectants: retrospective observational study

Blood cultures are indispensable for detecting life-threatening bacteremia. Little is known about associations between contamination rates and topical disinfectants for blood collection in adults. We sought to determine whether a change in topical disinfectants was associated with the rates of contaminated blood cultures in the emergency department of a single institution. This single-center, retrospective observational study of consecutive patients aged 20 years or older was conducted in the emergency department (ED) of a university hospital in Japan between August 1, 2018 and September 30, 2020. Pairs of blood samples were collected for aerobic and anaerobic culture from the patients in the ED. Physicians selected topical disinfectants according to their personal preference before September 1, 2019; alcohol/chlorhexidine gluconate (ACHX) was mandatory thereafter, unless the patient was allergic to alcohol. Regression discontinuity analysis was used to detect the effect of the mandatory usage of ACHX on rates of contaminated blood cultures. We collected 2141 blood culture samples from 1097 patients and found 164 (7.7%) potentially contaminated blood cultures. Among these, 445 (20.8%) were true bacteremia and 1532 (71.6%) were true negatives. Puncture site disinfection was performed with ACHX for 1345 (62.8%) cases and with povidone-iodine (PVI) for 767 (35.8%) cases. The regression discontinuity analysis showed that mandatory ACHX usage was significantly associated with lower rates of contaminated blood cultures by 9.6% (95% confidence interval (CI): 5.0%–14.2%, P < 0.001). Rates of contaminated blood cultures were significantly lower when ACHX was used as the topical disinfectant.

Comparing blood culture contamination rates by different sampling methods in a paediatric emergency department.

Blood culture contamination (BCC) can cause unnecessary hospitalisations and inappropriate use of antibiotics. The aim of this study was to find risk factors associated with BCCs in children and to compare contamination rates between open and closed blood culture collection systems. Data were prospectively collected regarding blood cultures obtained in the paediatric emergency department from February 26, 2020, to September 30, 2020, based on the method of drawing blood reported by the obtaining physician. A comparison between contaminated and non-contaminated blood cultures was performed. We also compared the composition of the contaminations in the study period to the same period in 2019. A total of 512 blood cultures were included, 33 (6.4%) of which were contaminated. The only parameter that was associated with an increased rate of contamination by 2.34 fold (95% CI 1.1-4.99, P=0.028) was obtaining blood through an 'open' system, using a syringe connected to a needle in order to draw blood from an open ended needle. The proportion of contaminations originating from oral flora decreased in the study period by 44.7% as compared to the same period in the previous year (13% vs. 23.5%, P= 0.056). 'Open system' method, which is commonly used in paediatric emergency departments for blood culture obtainment, was associated with an increase in BCC. Adherence to blood cultures obtainment guidelines, even at the price of two different blood tests, is important in order to reduce BCC rates in children.

S2649 Bacillus cereus Bacteremia in Alcoholic Cirrhosis

Introduction: Bacillus cereus (BC) is a gram positive, spore-forming environmental bacteria that can be found as transient normal human gastrointestinal (GI) flora. While BC is a common blood culture (BCx) contaminant, it can cause emetic or diarrheal foodborne illness via enterotoxin. This often resolves with supportive care. BC has been implicated in rare yet serious nosocomial and opportunistic infections in patients (pts) with hematological malignancies, intravenous drug use (IVDU), or indwelling devices. We present a case of non-GI BC infection in an alcoholic cirrhotic pt without traditional risk factors. Case Description/Methods: A 57-year-old female with diabetes (DM), alcohol use disorder, and alcoholic cirrhosis presented with malaise and worsening jaundice. Pt denied GI symptoms or fever. Pt received prednisone x 21 days for alcoholic hepatitis 2 weeks prior to admission and denied use since then. No history of IVDU. Pt was on spironolactone, thiamine, and folic acid. Physical exam showed stable vitals, intact mental status, non-distended and non-tender abdomen, and no cardiac murmur. MELD-Na on admission was 31 (Table 1). Toxicology screen, hepatitis A, B and C serology, EBV, and HIV were negative. Serum CMV PCR 27355 IU/mL. Multiple BCxs over 4 consecutive days were positive for BC. U/S abdomen was negative for hepatic lesions or ascites initially. Transesophageal echocardiogram was unremarkable. Pt was treated with IV vancomycin for 2 weeks. CMV treatment was deferred. Pt developed ascites during hospitalization without spontaneous bacterial peritonitis (SBP) and MELD-Na was 25 at discharge. Discussion: Cirrhotic pts are susceptible to infections due to associated immune dysfunction. Non-GI BC infections could be acquired exogenously via bacterial entry of disrupted skin or endogenously via ingestion of contaminated food. There are rare reports of BC bacteremia in cirrhotic pts causing SBP and necrotizing fasciitis. The pathogenesis was attributed to translocation of colonized Bacillus in the GI tract via increased intestinal permeability and hypoalbuminemia resulting in bacteremia or peritonitis due to impaired phagocytosis that failed to eradicate the infection. Our case demonstrated alcoholic cirrhosis with compounded immunocompromised status such as malnutrition, DM, steroid use, and CMV viremia could pose as a risk factor for non-GI BC infection and contribute to acute on chronic liver failure. Prompt recognition and treatment of BC infection is vital in cirrhotic pts to prevent fatality.Table 1.: Laboratory results on admission.