Risk Factors For Positive Cultures Research Articles

Risk factors for positive follow-up blood cultures in Gram-negative bacteremia among immunocompromised patients with neutropenia.

Gram-negative bacillary bloodstream infection (GN-BSI) is a frequent clinical challenge among immunocompromised hosts and is associated with a high mortality. The utility of follow-up blood cultures (FUBCs) for GN-BSI in this population, particularly in the setting of neutropenia, is poorly defined. We conducted a single-center, retrospective cohort study between the period of July 2018 and April 2022 to investigate the utility of FUBCs and delineate risk factors for positive cultures among neutropenic patients with monomicrobial GN-BSI. Univariate logistic regression was performed to assess risk factors associated with positive FUBCs. Of 206 patients, 98% had FUBCs performed, and 9% were positive. Risk factors for positive FUBCs included multidrug-resistant GN infection (OR 3.26; 95% confidence interval [CI] 1.22-8.72) and vascular catheter source (OR 4.82; CI 1.76-13.17). Among patients lacking these risk factors, the prevalence of positive FUBCs was low (2.8%) and the negative predictive value was 92%. Those with positive and negative FUBCs had similar rates of all-cause mortality (16.7% vs. 16.6%; p=.942) and microbiologic relapse (11.1% vs. 6.0%; p=.401) within 90-days of treatment completion. However, positive FUBCs were associated with prolonged hospitalization and longer duration of antimicrobial therapy. Positive FUBCs were infrequent in neutropenic patients with GN-BSI, and their occurrence did not significantly impact mortality or microbiologic relapse. Risk factors for positive FUBCs included multidrug resistant Gram-negative infection and vascular catheter source. Prospective studies will be necessary to elucidate the benefits and risks of FUBCs when managing GN-BSI in patients with underlying immune compromise.

Determining the prevalence and risk factors for positive bacterial culture in canine discospondylitis: 120 cases.

Identification of the aetiologic agent in canine discospondylitis is infrequent; and risk factors for a positive bacterial culture have not previously been reported. Medical records at three institutions were searched to identify clinical features of dogs with discospondylitis diagnosed via radiography or cross-sectional imaging. Inclusion in this retrospective case-control study required culture of one or more samples. Multivariable binary logistic regression identified features associated with a positive culture. Fifty (42%) of 120 dogs had one or more positive culture results obtained from either urine (28/115), blood (25/78), intervertebral disc aspiration (10/34) or cerebrospinal fluid (1/18). A positive culture was associated with higher bodyweight (p = 0.002, odds ratio [OR] = 1.054, 95% confidence interval [CI]: 1.019-1.089), more sample types cultured (p = 0.037, OR = 1.806, 95% CI: 1.037-3.147) and institution (p = 0.021). The presence of possibly associated preceding events (e.g., surgery), pyrexia, number of disc sites affected and serum C-reactive protein result, among other features, were not statistically significant. All isolates cultured were included since differentiation of true aetiologic agents from contaminants was not possible without histological confirmation and culture from surgical or postmortem biopsies. Clinical features typically associated with infection were not identified as risk factors for positive culture in canine discospondylitis. The statistical significance of the institution suggests that standardisation of sampling protocols is necessary.

Do Positive Cultures at Second Stage Re-Implantation Increase the Risk for Reinfection in Two-Stage Exchange for Periprosthetic Joint Infection?

BackgroundIntraoperative cultures are important in the diagnosis and targeted treatment of periprosthetic joint infection (PJI). Positive cultures at reimplantation during a two-stage exchange are discussed as a risk factor for reinfection. The aim of this study is the investigation of the incidence and risk factors for positive cultures during reimplantation. MethodsWe retrospectively identified 204 patients (111 knees, 93 hips) who were treated between 2012 and 2016 for PJI using a two-stage exchange protocol at a median follow-up of 42 months. PJI was diagnosed using the criteria of the musculoskeletal infection society (MSIS) of 2011. All cultural findings from first and second stage surgery were recorded. The primary endpoint was revision for infection. Risk factors for positive cultures and reinfection were analyzed. ResultsDuring reimplantation 25% (51/204) of patients had at least one positive culture, in 19.1% (39/204) only a single culture. Patients with culture-negative infections had a higher risk for positive cultures at reimplantation (HR 2.946 (95% CI 1.247-6.961), P = .014) and patients with infected total hip arthroplasty (THA) (HR 3.547 (95% CI 1.7-7.4), P = .001). Patients with positive cultures during reimplantation had a higher risk for reinfection (HR 2.27 (95% CI 1.181-4.363), P = .014) as well as patients with a single positive culture (HR 2.421 (95% CI 1.139-5.143), P = .021). ConclusionAs positive cultures are common and increase reinfection risk irrespective of their numbers, longer antibiotic therapy following reimplantation can be an option. Single positive cultures in reimplantation surgery should not be considered contamination.

Microbial Profiles and Risk Factors of Preexisting Biliary Infection in Patients with Therapeutic Endoscopy

Background The bile infection may already exist before the administration of an interventional procedure, despite no clinical manifestations of cholangitis detected. Blood cultures remained negative even in more than half of the febrile cases with cholangitis. Risk factors associated with bacterial growth in bile before the intervention are not well defined. To establish the bacterial profiles isolated from the bile samples and to identify risk factors for bacterial colonization in the bile system. Methods Individuals who underwent endoscopic retrograde cholangiopancreatography (ERCP) interventions were enrolled. Bile samples were aspirated and were immediately transferred into a sterile tube for storage. Results Positive bile cultures were detected in 363 (38.0%) of 956 patients, including 322 benign diseases and 41 malignances. Of 363 positive cases, 351 (96.7%) were monoinfection and 12 (3.3%) multi-infection. Escherichia coli were the most common Gram-negative bacteria (210, 56.0%), followed by Klebsiella pneumoniae (45, 12.0%). Enterococcus faecalis represented the most common Gram-positive microorganism (19, 5.07%), while Candida albicans (11, 2.93%) were the dominant fungi. Klebsiella pneumoniae were more frequently detected in malignant diseases (P = 0.046). Age, previous ERCP history or OLT history, and CBD diameter were independent risk factors for positive cultures (P < 0.05) while preoperative jaundice drug therapy was the protective factor for bile infection (P < 0.05). Conclusion Monomicrobial infection was dominant among all infections, and Klebsiella pneumoniae strains were more frequently isolated from patients with malignant diseases. To effectively manage patients who are at a high risk for bile infection, a detailed diagnosis and treatment plan for each case should be prepared.

Risk Factors for Positive Cultures in Presumed Aseptic Revision Spine Surgery.

Retrospective case-control study. To report culturing patterns and results in the setting of presumed aseptic revision spinal surgery. The indications for obtaining cultures in revision spinal surgery remain unclear in the absence of a definitive diagnosis of infection. Culture results and risk factors for having positive cultures in this setting have not been previously studied. We retrospectively reviewed 595 consecutive revision spine surgeries performed by four senior spine surgeons between 2008 and 2013. Preoperative workup revealed the diagnosis of infection in 17 cases which were excluded from review. The remaining 578 presumed aseptic cases were included. Univariate and multivariate analyses were performed to identify variables associated with obtaining cultures and risk factors for positive cultures. Cultures were obtained in 112 (19.4%) cases and were positive in 40.2%. Pseudarthrosis was the most common revision diagnosis when cultures were obtained (49.1%) and Propionibacterium acnes was the most common organism isolated from positive cultures (48.8%). Regarding culture results, multivariate analysis demonstrated that male sex (odds ratio [OR] = 3.4) and pseudarthrosis (OR = 4.1) were significantly associated with having positive cultures while fusion procedures (OR = 0.3) were negatively correlated, with area under the curve (AUC) 0.71. Unexpected positive cultures occurred commonly and P. acnes was the predominant isolated organism. Male sex, pseudarthrosis, and non-fusion cases predicted positive cultures. Considering these results, we recommend cultures be obtained in revision cases for pseudarthrosis, even in the setting of negative infectious work-up preoperatively. 4.

Wednesday, September 26, 2018 3:35 PM – 5:05 PM How to Avoid Complications: 95. Factors associated with the decision to culture and positive growth in aseptic revision spine surgery

BACKGROUND CONTEXT The indications for obtaining cultures in revision spinal surgery remain unclear in the absence of a definitive diagnosis of infection. Surgeon behavior related to obtaining cultures and risk factors for positive cultures in this setting have not been previously studied. PURPOSE To report on the specimen collection patterns and culture results during presumed aseptic revision spine cases. An improved understanding of what leads surgeons to exclude infection as well as the risk factors for having a positive culture will help inform future culturing practices, highlighting underlying characteristics which may increase the yield of taking intraoperative cultures in presumed aseptic revision cases. This data will aid surgeons, hospitals, and payers in what is currently a challenging clinical scenario. STUDY DESIGN/SETTING Retrospective review. PATIENT SAMPLE A total of 578. OUTCOME MEASURES Factors associated with the decision to obtain cultures intraoperatively in cases of aseptic revision spine surgery; risk factors for positive cultures obtained in such cases METHODS Following approval of the institutional review board, 595 consecutive revision spine surgeries performed by four senior surgeons between 2008 and 2013 were retrospectively reviewed. All revision surgeries including the cervical, thoracic, and lumbosacral spine employing fusion and non-fusion techniques with and without instrumentation were included. Routine preoperative evaluation of each of these patients included clinical examination, radiographs, and advanced imaging. In cases of suspected infection, preoperative measurement of serum white blood cell count, erythrocyte sedimentation rate, and C-reactive protein were obtained. The primary diagnosis at the time of revision surgery was identified in each case by the first ICD-9 code listed at the time of surgery. Cases were presumed aseptic if the principle preoperative diagnosis was not infection. Preoperative work-up revealed the diagnosis of infection in 17 cases which were excluded. A detailed chart review was performed on the remaining 578 cases. RESULTS Cultures were obtained in 112 (19.4%) cases and were positive in 40.2%. Pseudarthrosis was the most common revision diagnosis when cultures were obtained (49.1%) and Propionibacterium acnes was the most common organism isolated from positive cultures (48.8%). Multivariate analysis demonstrated that obesity (OR=2.4), instrumentation (OR=2.4), thoracolumbar surgery (OR=5.2), and diagnosis of implant failure (OR=9.0) or pseudarthrosis (OR=8.0) were significantly correlated with decision to culture while time between index and revision procedures (OR=0.9) and cervical surgery (OR=0.2) were negatively correlated, with AUC 0.85. Regarding culture results, multivariate analysis demonstrated that male sex (OR=3.4) and pseudarthrosis (OR=4.1) were significantly associated with having positive cultures while fusion procedures (OR = 0.3) were negatively correlated, with AUC 0.71. CONCLUSIONS Unexpected positive cultures occurred commonly and Propionibacterium acnes was the predominant isolated organism. Obesity, instrumentation, thoracolumbar surgery, implant failure, and pseudarthrosis all predicted culture collection. Male sex, pseudarthrosis, and non-fusion cases predicted positive cultures. Considering these results, we recommend cultures be obtained in revision cases for pseudarthrosis, even in the setting of negative infectious work-up preoperatively. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

Epidemiology and spectrum of positive bacteriological culture in intrauterine fluid collected from women with postmenopausal bleeding

This study aims to examine the prevalence and bacteriological findings of different types of intrauterine fluid collection in women presenting with postmenopausal bleeding and the risk factors for predicting positive microbiological culture, mixed growth, and anaerobic growth. This is a retrospective cohort study. Data from all of the women who were assessed in our one-stop postmenopausal bleeding clinic between 2008 and 2011 and who were found to have intrauterine fluid collection were reviewed. Endometrial aspirates of all women were sent for bacterial culture and histological examination. The risk factors for positive culture were assessed by both univariate and multivariate analyses. A total of 228 cases of intrauterine fluid collection were included for analysis. There were 109 (47.8%) cases of pyometra, 98 (43.0%) cases of hydrometra, and 21 (9.2%) cases of hematometra. Escherichia coli, Bacteroides fragilis, and Enterococcus were the commonest microorganisms isolated from endometrial aspirates. Both endometrial malignancy and benign intrauterine pathologies are not risk factors for positive culture. Advanced age (>75 y) is an independent risk factor for positive culture (odds ratio, 2.89; 95% CI, 1.39-6.01) and mixed growth (odds ratio, 2.18; 95% CI, 1.02-4.67). Residency in nursing homes is an independent risk factor for mixed growth (odds ratio, 2.61; 95% CI, 1.21-5.63) and anaerobic growth (odds ratio, 2.55; 95% CI, 1.01-6.44). E. coli, B. fragilis, and Enterococcus are the commonest microorganisms isolated from intrauterine fluid. Apart from drainage of the intrauterine fluid collection, successful management also requires appropriate antibiotics and improvement in perineal hygiene.