Person:

Klompas, Michael

Background. Five neuroinvasive Bacillus cereus infections (4 fatal) occurred in hospitalized patients with acute myelogenous leukemia (AML) during a 9-month period, prompting an investigation by infection control and public health officials. Methods. Medical records of case-patients were reviewed and a matched case-control study was performed. Infection control practices were observed. Multiple environmental, food, and medication samples common to AML patients were cultured. Multilocus sequence typing was performed for case and environmental B cereus isolates. Results. All 5 case-patients received chemotherapy and had early-onset neutropenic fevers that resolved with empiric antibiotics. Fever recurred at a median of 17 days (range, 9–20) with headaches and abrupt neurological deterioration. Case-patients had B cereus identified in central nervous system (CNS) samples by (1) polymerase chain reaction or culture or (2) bacilli seen on CNS pathology stains with high-grade B cereus bacteremia. Two case-patients also had colonic ulcers with abundant bacilli on autopsy. No infection control breaches were observed. On case-control analysis, bananas were the only significant exposure shared by all 5 case-patients (odds ratio, 9.3; P = .04). Five environmental or food isolates tested positive for B cereus, including a homogenized banana peel isolate and the shelf of a kitchen cart where bananas were stored. Multilocus sequence typing confirmed that all case and environmental strains were genetically distinct. Multilocus sequence typing-based phylogenetic analysis revealed that the organisms clustered in 2 separate clades. Conclusions. The investigation of this neuroinvasive B cereus cluster did not identify a single point source but was suggestive of a possible dietary exposure. Our experience underscores the potential virulence of B cereus in immunocompromised hosts.

Introduction: Claims-based analyses report that the incidence of sepsis-associated organ dysfunction is increasing. We examined whether coding practices for acute organ dysfunction are changing over time and if so, whether this is biasing estimates of rising severe sepsis incidence and severity. Methods: We assessed trends from 2005 to 2013 in the annual sensitivity and incidence of discharge ICD-9-CM codes for organ dysfunction (shock, respiratory failure, acute kidney failure, acidosis, hepatitis, coagulopathy, and thrombocytopenia) relative to standardized clinical criteria (use of vasopressors/inotropes, mechanical ventilation for ≥2 consecutive days, rise in baseline creatinine, low pH, elevated transaminases or bilirubin, abnormal international normalized ratio or low fibrinogen, and decline in platelets). We studied all adult patients with suspected infection (defined by ≥1 blood culture order) at two US academic hospitals. Results: Acute organ dysfunction codes were present in 57,273 of 191,695 (29.9 %) hospitalizations with suspected infection, most commonly acute kidney failure (60.2 % of cases) and respiratory failure (28.9 %). The sensitivity of all organ dysfunction codes except thrombocytopenia increased significantly over time. This was most pronounced for acute kidney failure codes, which increased in sensitivity from 59.3 % in 2005 to 87.5 % in 2013 relative to a fixed definition for changes in creatinine (p = 0.019 for linear trend). Acute kidney failure codes were increasingly assigned to patients with smaller creatinine changes: the average peak creatinine change associated with a code was 1.99 mg/dL in 2005 versus 1.49 mg/dL in 2013 (p <0.001 for linear decline). The mean number of dysfunctional organs in patients with suspected infection increased from 0.32 to 0.59 using discharge codes versus 0.69 to 0.79 using clinical criteria (p <0.001 for both trends and comparison of the two trends). The annual incidence of hospitalizations with suspected infection and any dysfunctional organ rose an average of 5.9 % per year (95 % CI 4.3, 7.4 %) using discharge codes versus only 1.1 % (95 % CI 0.1, 2.0 %) using clinical criteria. Conclusions: Coding for acute organ dysfunction is becoming increasingly sensitive and the clinical threshold to code patients for certain kinds of organ dysfunction is decreasing. This accounts for much of the apparent rise in severe sepsis incidence and severity imputed from claims.

Abstract Background: Discordance between in vitro susceptibility and empiric antibiotic therapy is inextricably linked to antibiotic resistance and decreased survival in bloodstream infections (BSI). However, its prevalence, patient- and hospital-level risk factors, and impact on outcome in a large cohort and across different pathogens remain unclear. Methods: We examined in vitro susceptibility interpretations for bacterial BSI and corresponding antibiotic therapy among inpatient encounters across 156 hospitals from 2000 to 2014 in the Cerner Healthfacts database. Discordance was defined as nonsusceptibility to initial therapy administered from 2 days before pathogen isolation to 1 day before final susceptibility reporting. Discordance prevalence was compared across taxa; risk factors and its association with in-hospital mortality were evaluated by logistic regression. Adjusted odds ratios (aOR) were estimated for pathogen-, patient- and facility-level factors. Results: Of 33,161 unique encounters with BSIs, 4,219 (13%) at 123 hospitals met criteria for discordant antibiotic therapy, ranging from 3% for pneumococci to 55% for E. faecium. Discordance was higher in recent years (2010–2014 vs. 2005–2009) and was associated with older age, lower baseline SOFA score, urinary (vs. abdominal) source and hospital-onset BSI, as well as ≥500-bed, Midwestern, non-teaching, and rural hospitals. Discordant antibiotic therapy increased the risk of death [aOR = 1.3 [95% CI 1.1–1.4]). Among Gram-negative taxa, discordant therapy increased risk of mortality associated with Enterobacteriaceae (aOR = 1.3 [1.0–1.6]) and non-fermenters (aOR = 1.7 [1.1–2.5]). Among Gram-positive taxa, risk of mortality from discordant therapy was significantly higher for S. aureus (aOR = 1.3 [1.1–1.6]) but unchanged for streptococcal or enterococcal BSIs. Conclusion: The prevalence of discordant antibiotic therapy displayed extensive taxon-level variability and was associated with patient and institutional factors. Discordance detrimentally impacted survival in Gram-negative and S. aureus BSIs. Understanding reasons behind observed differences in discordance risk and their impact on outcomes could inform stewardship efforts and guidelines for empiric therapy in sepsis. Disclosures All authors: No reported disclosures.

Background: Sepsis is the focus of national quality improvement programs and a recent public reporting measure from the Centers for Medicare and Medicaid Services. However, diagnosing sepsis requires interpreting nonspecific signs and can therefore be subjective. We sought to quantify interobserver variability in diagnosing sepsis. Methods: We distributed five case vignettes of patients with suspected or confirmed infection and organ dysfunction to a sample of practicing intensivists. Respondents classified cases as systemic inflammatory response syndrome, sepsis, severe sepsis, septic shock, or none of the above. Interobserver variability was calculated using Fleiss’ κ for the five-level classification, and for answers dichotomized as severe sepsis/septic shock versus not-severe sepsis/septic shock and any sepsis category (sepsis, severe sepsis, or septic shock) versus not-sepsis. Results: Ninety-four physicians completed the survey. Most respondents (88 %) identified as critical care specialists; other specialties included pulmonology (39 %), anesthesia (19 %), surgery (9 %), and emergency medicine (9 %). Respondents had been in practice for a median of 8 years, and 90 % practiced at academic hospitals. Almost all respondents (83 %) felt strongly or somewhat confident in their ability to apply the traditional consensus sepsis definitions. However, overall interrater agreement in sepsis diagnoses was poor (Fleiss’ κ 0.29). When responses were dichotomized into severe sepsis/septic shock versus not-severe sepsis/septic shock or any sepsis category versus not-sepsis, agreement was still poor (Fleiss’ κ 0.23 and 0.18, respectively). Seventeen percent of respondents classified one of the five cases as severe sepsis/septic shock, 27.7 % rated two cases, 33.0 % respondents rated three cases, 19.2 % rated four cases, and 3.2 % rated all five cases as severe sepsis/septic shock. Among respondents who felt strongly confident in their ability to use sepsis definitions (n = 45), agreement was no better (Fleiss’ κ 0.28 for the five-category classification, and Fleiss’ κ 0.21 for the dichotomized severe sepsis/septic shock classification). Cases were felt to be extremely or very realistic in 74 % of responses; only 3 % were deemed unrealistic. Conclusions: Diagnosing sepsis is extremely subjective and variable. Objective criteria and standardized methodology are needed to enhance consistency and comparability in sepsis research, surveillance, benchmarking, and reporting. Electronic supplementary material The online version of this article (doi:10.1186/s13054-016-1266-9) contains supplementary material, which is available to authorized users.