Clinical characteristics and outcome of 125 polymicrobial bloodstream infections in hematological patients: an 11-year epidemiologic survey

Hospital-acquired bloodstream infections in patients with cancer: current knowledge and future directions

Patients with cancer experience higher rates of preventable harm from hospital-acquired bloodstream infections (haBSIs) and central-line-associated bloodstream infections (CLABSIs) compared with the general hospital population. The prevention of haBSIs and CLABSIs in patients with cancer is an urgent priority, and requires standardized surveillance and reporting efforts. The application of haBSI and CLABSI definitions, classification systems and surveillance strategies for patients with cancer is complex, and there is wide variation in clinical practice. Existing systems were not designed explicitly for patients with cancer, and have different strengths and weaknesses in the cancer setting. For these reasons, epidemiological estimates of haBSIs and CLABSIs in patients with cancer also require careful interpretation. This complexity can be a barrier to identifying appropriate targets for intervention and reducing preventable harm. This review provides an overview of key concepts and challenges in haBSI surveillance and prevention specific to patients with cancer. In addition, this review summarizes the strengths and weaknesses of commonly used surveillance definitions and denominators in the setting of cancer care; existing surveillance practice; epidemiology of haBSIs and CLABSIs; prevention strategies; and current knowledge gaps. A global collaborative effort to harmonize the surveillance of hospital-acquired infections in patients with cancer would be invaluable to improve the accuracy and utility of existing data, advance efforts to prevent hospital-acquired infections, and improve patient safety.

Clinical characteristics and mortality risk factors of mixed bacterial infections in hematopoietic stem cell transplantation recipients

Background and objective

Mixed bacterial infections (MBI) is one of the complications after hematopoietic stem cell transplantation (HSCT) and increases the risk of patient death. However, there are few reports specifically on this topic. The purpose of this study was to investigate the clinical characteristics and mortality risk factors of MBI in HSCT recipients.

Methods

The electronic medical records of patients undergoing HSCT were collected. The epidemiological features and antibiotic resistance of patients with and without MBI were compared. Logistic regression and Cox regression were used to identify the risk factors for MBI acquisition and death. R language was used to construct a prediction model for the overall survival of HSCT recipients with MBI.

Results

The cumulative incidence of MBI was 6.3% and the mortality was 48.8%. Time interval from diagnosis to transplantation > 180 days (HR=2.059, 95% CI 1.042-4.069, P=0.038) and ICU admission after transplantation (HR=2.271, 95% CI 1.053-4.898, P=0.036) were independent risk factors for MBI acquisition. Engraftment period > 20 days (HR=2.273, 95% CI 1.028-5.027, P=0.043), continuous renal replacement therapy (HR=5.755, 95% CI 1.691-19.589, P=0.005) and septic shock (HR=4.308, 95% CI 2.085-8.901, P=0.000) were independent risk factors associated with mortality.

Conclusions

MBI has become a serious problem that cannot be ignored after HSCT. It is urgent for clinicians to pay high attention to it and formulate reasonable monitoring and treatment plans to improve the prognosis of patients.

Microbiological Analysis and Mortality Risk Factors in Patients with Polymicrobial Bloodstream Infections

Purpose

To study the etiological characteristics and risk factors affecting the prognosis of patients with polymicrobial bloodstream infections.

Patients and Methods

Overall, 141 patients with polymicrobial bloodstream infections in Henan Provincial People's Hospital during 2021 were included. Laboratory test indexes, department of admission, sex, age, intensive care unit (ICU) admission, surgical history, and central venous catheter placement were collected. Patients were divided into surviving and deceased groups based on outcomes at discharge. Mortality risk factors were identified by univariate and multivariable analyses.

Results

Seventy-two of 141 patients survived. Patients were mainly from the ICU and the Departments of Hepatobiliary Surgery and Hematology. Overall, 312 microbial strains were detected: 119 gram-positive, 152 gram-negative, and 13 anaerobic bacteria and 28 fungi. Among the gram-positive bacteria, coagulase-negative staphylococci were most frequent (44/119, 37%), followed by enterococci (35/119, 29.4%). Among coagulase-negative staphylococci, methicillin-resistant coagulase-negative staphylococci incidence was 75% (33/44). Among gram-negative bacteria, Klebsiella pneumoniae was most common (45/152, 29.6%), followed by Escherichia coli (25/152, 16.4%) and Pseudomonas aeruginosa (13/152, 8.6%). Among K. pneumoniae, the incidence of carbapenem-resistant (CR) K. pneumoniae was 45.7% (21/45). On univariate analysis, mortality risk factors included increased white blood cells and C-reactive protein, decreased total protein and albumin, CR strains, ICU admission, central venous catheter, multiple organ failure, sepsis, shock, pulmonary diseases, respiratory failure, central nervous system diseases, cardiovascular diseases, hypoproteinemia, and electrolyte disturbances (P < 0.05). Multivariable analysis showed that ICU admission, shock, electrolyte disorders, and central nervous system diseases were independent mortality risk factors. The survival curve shows that the survival rate of patients with polymicrobial CR bloodstream infections was lower than that of patients with polymicrobial non-CR bloodstream infections (P=0.029).

Conclusion

Patients with polymicrobial bloodstream infections are typically critically ill and harbor multidrug-resistant bacteria. Thus, to minimize mortality rate in critically ill patients, changes in infectious flora should be monitored, antibiotics selected reasonably, and invasive procedures reduced.

Clinical outcomes of antimicrobial resistance in cancer patients: a systematic review of multivariable models

BACKGROUND

Infections are major causes of disease in cancer patients and pose a major obstacle to the success of cancer care. The global rise of antimicrobial resistance threatens to make these obstacles even greater and hinder continuing progress in cancer care. To prevent and handle such infections, better models of clinical outcomes building on current knowledge are needed. This internally funded systematic review (PROSPERO registration: CRD42021282769) aimed to review multivariable models of resistant infections/colonisations and corresponding mortality, what risk factors have been investigated, and with what methodological approaches.

METHODS

We employed two broad searches of antimicrobial resistance in cancer patients, using terms associated with antimicrobial resistance, in MEDLINE and Embase through Ovid, in addition to Cinahl through EBSCOhost and Web of Science Core Collection. Primary, observational studies in English from January 2015 to November 2021 on human cancer patients that explicitly modelled infection/colonisation or mortality associated with antimicrobial resistance in a multivariable model were included. We extracted data on the study populations and their malignancies, risk factors, microbial aetiology, and methods for variable selection, and assessed the risk of bias using the NHLBI Study Quality Assessment Tools.

RESULTS

Two searches yielded a total of 27,151 unique records, of which 144 studies were included after screening and reading. Of the outcomes studied, mortality was the most common (68/144, 47%). Forty-five per cent (65/144) of the studies focused on haemato-oncological patients, and 27% (39/144) studied several bacteria or fungi. Studies included a median of 200 patients and 46 events. One-hundred-and-three (72%) studies used a p-value-based variable selection. Studies included a median of seven variables in the final (and largest) model, which yielded a median of 7 events per variable. An in-depth example of vancomycin-resistant enterococci was reported.

CONCLUSIONS

We found the current research to be heterogeneous in the approaches to studying this topic. Methodological choices resulting in very diverse models made it difficult or even impossible to draw statistical inferences and summarise what risk factors were of clinical relevance. The development and adherence to more standardised protocols that build on existing literature are urgent.

Clinical Outcome in Children With Cancer With Two or More Microorganisms Isolated From Blood Cultures During Episodes of Fever and Neutropenia

BACKGROUND

Bacterial bloodstream infections are a major cause of morbidity and mortality in children with cancer and episodes of fever and neutropenia (FN). The aim of this study was to evaluate the clinical outcome in children with cancer with 2 or more microorganisms isolated from blood cultures during their episodes of FN.

METHODS

Between 2016 and 2021, children presenting with high-risk FN, admitted to any of the 6 participating hospitals in Santiago, Chile, were included in this study if they have positive blood cultures. We compared the clinical outcome of children with 2 or more microorganisms versus those with single agent isolation.

RESULTS

A total of 1074 episodes of high-risk FN were enrolled in the study period, of which 27% (298) had positive blood cultures and 3% (32) had 2 or more microorganisms isolated from blood cultures. The most frequent identified agents were Viridans group streptococci and Escherichia coli in 20%, followed by Coagulase negative staphylococci in 14%. Children with 2 or more microorganisms presented more days of fever (7 vs. 4 days, P = 0.02), needed longer courses of antimicrobial therapy (16 vs. 14 days, P = 0.04) and had higher mortality at day 30 (13% vs. 1%, P = 0.003).

CONCLUSIONS

Children with cancer and FN with 2 or more microorganisms isolated from blood cultures had a worse clinical outcome than children with single agent isolation.