Challenges and Opportunities in Antimicrobial Stewardship among Hematopoietic Stem Cell Transplant and Oncology Patients.

Antimicrobial stewardship programs play a critical role in optimizing the use of antimicrobials against pathogens in the era of growing multi-drug resistance. However, implementation of antimicrobial stewardship programs among the hematopoietic stem cell transplant and oncology populations has posed challenges due to multiple risk factors in the host populations and the infections that affect them. The consideration of underlying immunosuppression and a higher risk for poor outcomes have shaped therapeutic decisions for these patients. In this multidisciplinary perspective piece, we provide a summary of the current landscape of antimicrobial stewardship, unique challenges, and opportunities for unmet needs in these patient populations.

Impact of phenotypic rapid diagnostic assay on duration of empiric antibiotics for gram-negative bacteremia.

Objective: Rapid diagnostic tests (RDTs) are increasingly being implemented as antimicrobial stewardship tools to facilitate antibiotic modification and reduce complications related to their overutilization. We measured the clinical impact of a phenotypic RDT with antimicrobial stewardship (AMS) in the setting of gram-negative bacteremia. Setting and participants: In this single-center retrospective cohort study, we evaluated adult patients with gram-negative bacteremia who received at least 72 hours of an antibiotic. Methods: The primary outcome was the duration of empiric antibiotic therapy for gram-negative bacteremia. Secondary outcomes included time-to-directed therapy, proportion of modifications, hospital length of stay (LOS), and subsequent infection with a multidrug-resistant organism (MDRO) or C. difficile infection (CDI). Results: The duration of empiric antibiotics decreased in the RDT+AMS group (4 days vs 2 days; P < .01). Time to directed therapy decreased from 75.0 to 27.9 hours (P < .01). Conclusions: The clinical outcomes of LOS, MDRO, and CDI were reduced. The phenotypic RDT demonstrated an improvement in stewardship measures and clinical outcomes.

Safety and Effectiveness of High-Dose Cefazolin in Patients With High Body Weight: A Retrospective Cohort Study.

Background: Cefazolin is a commonly used antibiotic for the treatment of mild to severe infections. Despite the use of higher dose of cefazolin (3 g/dose) for surgical prophylaxis in patients with obesity, there is currently a paucity of data identifying the optimal dose to treat infections in this specific patient population. Methods: This was a multicenter, retrospective cohort study of patients who received cefazolin at weight-based (up to 9 g/day) or standard doses (up to 6 g/day) for the treatment of bacteremia or skin and soft tissue infection (SSTI). Study groups were stratified by body weight and cefazolin dose received. Primary outcome was the composite of treatment-emergent adverse events (TEAEs) and secondary outcome was treatment failure rate. Results: A total of 208 patients were included for study analysis. Fifty-nine patients had body weight >120 kg. Of these, 33 received high-dose cefazolin while 26 received standard doses. The remaining 149 patients had body weight of ≤120 kg and received standard doses. The occurrence of TEAEs did not differ across the 3 groups. The study also did not find any difference between the rate of treatment failure between groups. Conclusions: High-dose cefazolin (9 g/day) for the treatment of bacteremia or SSTIs in patients with high body weight was safe and well tolerated. Larger studies are needed to further explore the benefit of high-dose cefazolin in improving clinical outcomes.

Unusual Mycobacterium marinum Infection in a Heart Transplant Recipient: A Case Report.

Mycobacterium marinum (M. marinum) is a species of nontuberculous mycobacteria that is a rare cause of disease in humans and is usually associated with aquatic exposures. Symptoms manifest, on average, three weeks after exposure, although cases with longer incubation periods have been reported in the literature. Herein, we describe an unusual case presentation of an M. marinum infection in the left upper extremity of a heart transplant recipient. The case is notable for its prolonged incubation period and for being the first documented case of M. marinum infection in a heart transplant recipient. We hypothesize that, given the patient's immunosuppressive medication regimen in the post-transplant period, this case could represent a reactivation phenomenon of a latent infection.

Prevention of infection and optimizing vaccination in the solid organ transplant candidate and recipient.

PURPOSE OF REVIEW: Infections can result in serious complications in solid organ transplant (SOT) patients. The need to remain up to date on recommendations on screening, vaccinations, and chemoprophylaxis is paramount in the management of SOT patients. The goal of this review is to provide an overview of current recommendations for the prevention of infections and optimization of vaccinations from the pretransplant through posttransplant periods. RECENT FINDINGS: There is an emphasis on thorough pretransplant evaluation to guide clinicians and pretransplant testing based on epidemiological and endemic risk factors. Additionally, recent studies on vaccine safety and efficacy of newer vaccine formulations in SOT recipients are addressed. SUMMARY: This review provides insight on updated recommendations for pretransplant screening, new data on vaccine optimization in SOT recipients and posttransplant prophylaxis. Further research is needed in order to improve preventive measures including screening tests, vaccines, and chemoprophylaxis.

Risk Factors and Outcomes of Hospitalized Patients With Severe Coronavirus Disease 2019 (COVID-19) and Secondary Bloodstream Infections: A Multicenter Case-Control Study.

BACKGROUND: Coronavirus disease 2019 (COVID-19) has become a global pandemic. Clinical characteristics regarding secondary infections in patients with COVID-19 have been reported, but detailed microbiology, risk factors, and outcomes of secondary bloodstream infections (sBSIs) in patients with severe COVID-19 have not been well described. METHODS: We performed a multicenter case-control study including all hospitalized patients diagnosed with severe COVID-19 and blood cultures drawn from 1 March 2020 to 7 May 2020 at 3 academic medical centers in New Jersey. Data collection included demographics, clinical and microbiologic variables, and patient outcomes. Risk factors and outcomes were compared between cases (sBSI) and controls (no sBSI). RESULTS: A total of 375 hospitalized patients were included. There were 128 sBSIs during the hospitalization. For the first set of positive blood cultures, 117 (91.4%) were bacterial and 7 (5.5%) were fungal. Those with sBSI were more likely to have altered mental status, lower mean percentage oxygen saturation on room air, have septic shock, and be admitted to the intensive care unit compared with controls. In-hospital mortality was higher in those with an sBSI versus controls (53.1% vs 32.8%, P = .0001). CONCLUSIONS: We observed that hospitalized adult patients with severe COVID-19 and sBSI had a more severe initial presentation, prolonged hospital course, and worse clinical outcomes. To maintain antimicrobial stewardship principles, further prospective studies are necessary to better characterize risk factors and prediction modeling to better understand when to suspect and empirically treat for sBSIs in severe COVID-19.

Use of Tocilizumab for COVID-19-Induced Cytokine Release Syndrome: A Cautionary Case Report.

Novel coronavirus disease 2019 (COVID-19) emerged in late December 2019 in Wuhan, China. Since then, COVID-19 has become a pandemic affecting more than 4.1 million people worldwide. Patients with COVID-19 have a wide spectrum of manifestations, one being cytokine release syndrome (CRS) and its fatal correlate, secondary hemophagocytic lymphohistiocytosis (sHLH). Anti-cytokine therapy such as tocilizumab, an IL-6 receptor antagonist, is a potential treatment for COVID-19; however, data regarding the efficacy of this anti-IL-6 therapy are currently lacking. We report two cases of patients who received a diagnosis of COVID-19 complicated by CRS and were treated with tocilizumab. Both patients progressed to sHLH despite treatment with tocilizumab, and one developed viral myocarditis, challenging the safety and clinical usefulness of tocilizumab in the treatment of COVID-19-induced CRS. These cases highlight the need for clinical trials to determine optimal patient selection and timing for the use of tocilizumab during this disease process.

Infections due to multidrug-resistant organisms following heart transplantation: Epidemiology, microbiology, and outcomes.

BACKGROUND: Infections secondary to multidrug-resistant organisms (MDRO) have emerged as a growing problem in solid organ transplantation (SOT). Most of the published data on MDRO infections in SOT pertains to abdominal organ transplantation and data specific to heart transplantation (HT) are limited. METHODS: This is a retrospective review of HT recipients at our institution from 2011 to 2016; with the aim to investigate the epidemiology, microbiologic spectrum, and outcomes in patients with post-HT MDRO infections, classified as multidrug-resistant (MDR), extensively drug-resistant (XDR), and pandrug-resistant (PDR) using standardized definitions. RESULTS: Of the 149 HT recipients, 82 episodes of bacterial infection were seen in 46 patients (31%) in the year following HT. Thirty (37%) were due to MDR pathogens and 13 (16%) were XDR. The most common gram-negative MDR pathogens were extended-spectrum beta-lactamase (ESBL) Escherichia coli and Klebsiella pneumoniae; while XDR pathogens were most commonly Pseudomonas aeruginosa followed by carbapenem-resistant Klebsiella pneumoniae. Majority of infection episodes were bloodstream (54, 66%) followed by pulmonary infection (20, 24%). Within a year after transplant, HT recipients with any bacterial infection had significantly higher mortality versus those without infection; and XDR infections were associated with a 26-fold greater hazard of death on average compared to those without infection (adjusted HR, 26.1; 95% CI, 6.4-107.0; P < .001). There were no PDR infections. CONCLUSION: Bacterial infections were a significant predictor of 1-year post-HT mortality, which was highest among those with XDR infections. This study highlights the burden of MDRO infections in HT recipients and identifies an area of future research.