Solid organ transplant patients: are there opportunities for antimicrobial stewardship?

Toward an optimization of empirical antibiotic therapy in acute graft pyelonephritis: A retrospective multicenter study

OBJECTIVE

Acute graft pyelonephritis (AGPN) is the most frequent infectious complication in kidney transplant recipients (KTR). The treatment of acute community-acquired (CA) pyelonephritis is based on third-generation cephalosporins (3GC) and fluoroquinolones. Cefepime or a piperacillin-tazobactam combination are more often used in healthcare-associated (HCA) infections. However, these recommendations do not consider the resistance observed in KTRs. The objective of our study was to define the most appropriate empirical antibiotherapy for AGPN in KTRs according to the CA and HCA settings. To answer this question, we assessed the prevalence of resistance to different antibiotics usually recommended for urinary tract infections (UTIs) in the general population.

METHODS

Observational, retrospective, multicenter study covering all episodes of AGPN occurring in hospitalized KTRs in 2019.

RESULTS

A total of 210 patients were included in 7 centers and 244 episodes of AGPN were analyzed (158 CA-AGPN and 86 HCA-AGPN). The prevalence of 3GC and fluoroquinolone resistance was 23 % (n = 36) and 30 % (n = 50) in CA infections (n = 158), and 47 % (n = 40) and 31 % (n = 27) in HCA infections (n = 86), respectively. Cefepime resistance rate was 19 % (n = 30) in CA-AGPN and 29 % (n = 25) in HCA-AGPN. Piperacillin-tazobactam combination had resistance rates > 15 % in both CA and HCA infections. The only antimicrobials with resistance rates < 10 % were aminoglycosides and carbapenems.

CONCLUSION

None of the antibiotics recommended in empirical treatment in UTIs has shown a resistance rate of less than 10% with regard to AGPN. Therefore, none of them should be used as monotherapy. A combination therapy including amikacin could be an appropriate strategy in this setting.

The Burden and Impact of Early Post-transplant Multidrug-Resistant Organism Detection Among Renal Transplant Recipients, 2005-2021

Background

Reducing the burden of multidrug-resistant organism (MDRO) colonization and infection among renal transplant recipients (RTRs) may improve patient outcomes. We aimed to assess whether the detection of an MDRO or a comparable antibiotic-susceptible organism (CSO) during the early post-transplant (EPT) period was associated with graft loss and mortality among RTRs.

Methods

We conducted a retrospective cohort study of RTRs transplanted between 2005 and 2021. EPT positivity was defined as a positive bacterial culture within 30 days of transplant. The incidence and prevalence of EPT MDRO detection were calculated. The primary outcome was a composite of 1-year allograft loss or mortality following transplant. Multivariable Cox hazard regression, competing risk, propensity score-weighted sensitivity, and subgroup analyses were performed.

Results

Among 3507 RTRs, the prevalence of EPT MDRO detection was 1.3% (95% CI, 0.91%-1.69%) with an incidence rate per 1000 EPT-days at risk of 0.42 (95% CI, 0.31-0.57). Among RTRs who met survival analysis inclusion criteria (n = 3432), 91% (3138/3432) had no positive EPT cultures and were designated as negative controls, 8% (263/3432) had a CSO detected, and 1% (31/3432) had an MDRO detected in the EPT period. EPT MDRO detection was associated with the composite outcome (adjusted hazard ratio [aHR], 3.29; 95% CI, 1.21-8.92) and death-censored allograft loss (cause-specific aHR, 7.15; 95% CI, 0.92-55.5; subdistribution aHR, 7.15; 95% CI, 0.95-53.7). A similar trend was seen in the subgroup and sensitivity analyses.

Conclusions

MDRO detection during the EPT period was associated with allograft loss, suggesting the need for increased strategies to optimize prevention of MDRO colonization and infection.

Antimicrobial Stewardship in Immunocompromised Patients: Current State and Future Opportunities

Immunocompromised (IC) patients are high risk for complications due to a high rate of antibiotic exposure. Antimicrobial stewardship interventions targeted to IC patients can be challenging due to limited data in this population and a high risk of severe infection-related outcomes. Here, the authors review immunocompromised antimicrobial stewardship barriers, metrics, and opportunities for antimicrobial use and testing optimization. Last, the authors highlight future steps in the field.

A joint program of antimicrobial stewardship and hospital-acquired infection control to reduce healthcare-associated infections after kidney transplantation: The Hipomenes study

Infection is a common complication in kidney transplant recipients (KTRs). The usefulness of antimicrobial stewardship programs (ASP) and hospital-acquired infection control (HAIC) initiatives in the general inpatient population is well established. We performed a quasi-experimental study to evaluate a joint ASP/HAIC initiative focused on KTRs. A dedicated ASP team optimized antimicrobial prescriptions in consecutive KTRs during the intervention period (June 2015-March 2016). A multifaceted, evidence-based HAIC program was concurrently implemented. Results were compared with the preceding period (June 2014-March 2015). We included 96 and 100 KTRs in the intervention and preintervention periods, respectively. There was a reduction in the consumption of meropenem (rate ratio [RR]: 0.63; 95% confidence interval [CI]: 0.53-0.75; P <.0001), ceftazidime (RR: 0.31; 95% CI: 0.21-0.45; P <.0001), vancomycin (RR: 0.65; 95% CI: 0.53-0.8; P <.0001), and ciprofloxacin (RR: 0.66; 95% CI: 0.55-0.81; P <.0001) and an increase of fosfomycin (RR: 1.80; 95% CI: 1.17-2.76; P =.008) during the intervention period. The incidence of cystitis (RR: 0.30; 95% CI: 0.28-0.33; P <.001) and upper urinary tract infection (RR: 0.56; 95% CI: 0.33-0.95; P =.04) decreased. A specific ASP/HAIC initiative was effective in optimizing antimicrobial use and reducing the incidence of common bacterial infections among KTRs.

Opportunities for Antimicrobial Stewardship Interventions Among Solid Organ Transplant Recipients

Although antimicrobial stewardship programs have excelled over the past decade, uptake and application of these programs to special populations such as solid organ transplant recipients have lagged. Here, we review the value of antimicrobial stewardship for transplant centers and highlight data supporting interventions that are ripe for adoption. In addition, we review the design of antimicrobial stewardship initiatives, targets for both syndromic and system-based interventions.

Antibiotic stewardship implementation at the largest solid organ transplantation center in Asia: a retrospective cohort study

BACKGROUND

Using Antimicrobial stewardship programs (ASP) to monitor the use of antibiotics can lead to improved antibiotic use and reduced costs.

METHODS

This retrospective cohort study was done at Shiraz Organ Transplant Center, the largest transplant center in Asia. Antimicrobial use, cost, clinical outcomes, and antibiotic resistance pattern were evaluated before and after ASP.

RESULTS

This study included 2791 patients, 1154 of whom were related to the time before ASP and 1637 to the time after ASP. During the period of the research, a total of 4051 interventions were done. The use of all classes of antibiotics was significantly reduced by ASP, with 329 DDD/100PD before the intervention compared to 201 DDD/100PD after it (p = 0.04). In addition, the overall cost of antibiotics purchased was much lower after the ASP measures were implemented ($43.10 per PD) than before implementation of the ASP measures ($60.60 per PD) (p = 0.03). After the implementation of ASP, the number of MDR isolates was significantly reduced.

CONCLUSION

The results of our study showed that the implementation of ASP significantly reduced the number and costs of antibiotics and also the number of resistant pathogens, but did not affect the patients' length of stay.

Perioperative antibiotic stewardship in the organ transplant setting

BACKGROUND

Solid organ transplant (SOT) recipients can benefit from traditional antimicrobial stewardship (AMS) activities directed to improve judicious perioperative prescribing and management, but evidence is lacking. The aim of this expert opinion review is to provide an update on the current landscape of application of AMS practices for optimization of perioperative prophylaxis (PP).

METHODS

We reviewed the available literature on early postoperative infectious complications in SOT and PP management, on modified perioperative approaches in case of infection or colonization in recipients and donors and on AMS in transplantation PP.

RESULTS

SOT recipients are at high risk for early postoperative infectious complications due to the complexity of surgical procedures, severity of end stage organ disease, net state of immunosuppression in the posttransplant period and to the high risk for multidrug resistant organism. Moreover, SOT may be exposed to preservation fluid infections and expected or unexpected donor-derived infections. We summarize main factors to take into account when prescribing transplant PP.

CONCLUSION

Creating personalized PP to avoid unwanted consequences of antimicrobials while improving outcomes is an emerging and critical aspect in SOT setting. Further studies are needed to offer best PP tailored to SOT type and to evaluate interventions efficacy and safety.

Current state of antimicrobial stewardship and organ transplantation in Spain

INTRODUCTION

Solid-organ transplantation (SOT) remains the best therapeutic option for end-stage organ disease. Regrettably, SOT recipients are disproportionately affected by nosocomial infections produced by multidrug-resistant (MDR) microorganisms and antimicrobial adverse events. Both have a negative impact on the patient´s outcome.

METHODS

Description of data concerning the antimicrobial stewardship program (ASP) in SOT recipients of the University Hospital "12 de Octubre", and review of other Spanish ASPs.

RESULTS

From May 2017 to December 2021, the ASP issued 2.785 recommendations. Approximately, 4.9% were aimed at improving the antimicrobial treatment administered to SOT recipients. Treatment discontinuation or change to a better therapeutic regimen was recommended in 51.8% and 26.3% of cases, respectively. The acceptance rate of the recommendations was close to 92%. Between June 2015 and March 2016, a quasi-experimental study consisting of a joint ASP and hospital-acquired infection control (HAIC) initiative, which included kidney transplant recipients, reported a significant reduction in the consumption of meropenem, vancomycin and ciprofloxacin, and a reduction in the incidence of global bacterial infections, upper urinary tract infections, and cystitis. Although Spain has several robust regional ASPs (e.g., VINCat and PIRASOA), data specifically concerning SOT patients is lacking.

CONCLUSION

ASP coupled with HAIC programs have proven to be effective in SOT, and should be implemented in centers that perform transplantation. Since data is scarce, Spanish centers which have ASP should report their experience in SOT. Understanding the efficacy and safety of the Spanish ASP´s intervention in the SOT population is essential and deserves further study.

Antimicrobial stewardship programs in solid-organ transplant recipients in Switzerland

INTRODUCTION

Antimicrobial stewardship programs (ASPs) are essential for minimizing the emergence of antimicrobial resistance, while improving patient outcomes. The current status of ASP in the field of organ transplantation in Switzerland has not been well characterized.

METHODS

We describe in this article the current status of ASP and discuss challenges and opportunities of implementing ASP dedicated to solid-organ transplant (SOT) recipients in Switzerland.

RESULTS

ASP have been implemented in the Swiss healthcare system over the last years, although specific strategies for SOT recipients are mostly based on transplant infectious diseases (TID) consultations rather than structured institutional interventions. Even so, there is a unique opportunity for developing a successful ASP in Switzerland that also specifically addresses areas of practice relevant to SOT recipients. This is due to the existent network of TID specialists in close collaboration with transplant physicians, the small number of centers involved in the care of transplant recipients, and the development of the Swiss Transplant Cohort Study (STCS), a prospective nationwide cohort of SOT recipients in Switzerland. The STCS can identify actual challenges through the updated reports on the epidemiology on transplant infections, accurately monitor the impact of potential antimicrobial stewardship interventions, and represent an opportunity for nesting of pragmatic randomized controlled trials to address key questions about optimized antibiotic use for SOT recipients.

CONCLUSIONS

Although ASP in SOT recipients rely more on specific TID consultations than in general antimicrobial stewardship teams, we identified several opportunities for the implementation of a successful ASP in Switzerland.

Antimicrobial stewardship in solid organ transplant recipients: Current challenges and proposed metrics

BACKGROUND

Solid organ transplant (SOT) recipients are challenging populations for antimicrobial stewardship interventions due to a variety of reasons, including immunosuppression, consequent risk of opportunistic and donor-derived infections, high rates of infection with multi-drug resistant organisms (MDROs), Clostridioides difficile, and need for prolonged antimicrobial prophylaxis. Despite this, data on stewardship interventions and metrics that address the distinct needs of these patients are limited.

METHODS

We performed a narrative review of the current state of antimicrobial stewardship in SOT recipients, existing interventions and metrics in this population, and considerations for implementation of transplant-specific stewardship programs.

RESULTS

Antimicrobial stewardship metrics are evolving even in the general patient population. Data on metrics applicable to the SOT population are even more limited. Standard process, outcomes, and balancing metrics may not always apply to the SOT population. A successful stewardship program for SOT recipients requires reviewing existing data, applying general stewardship principles, and understanding the nuances of SOT patients.

CONCLUSION

As antimicrobial stewardship interventions are being implemented in SOT recipients; new metrics are needed to assess their impact. In conclusion, SOT patients present a challenging but important opportunity for antimicrobial stewards.

ABBREVIATIONS

SOT, antimicrobial stewardship program, MDRO, Clostridioides difficile infection, Centers for Disease Control and Prevention, Infectious Diseases Society of America, prospective audit and feedback, hematopoietic cell transplant, cytomegalovirus, trimethoprim-sulfamethoxazole, surgical site infections, nucleic acid amplification testing, days of therapy, defined daily dose, and length of stay.

White paper on antimicrobial stewardship in solid organ transplant recipients

Antimicrobial stewardship programs (ASPs) have made immense strides in optimizing antibiotic, antifungal, and antiviral use in clinical settings. However, although ASPs are required institutionally by regulatory agencies in the United States and Canada, they are not mandated for transplant centers or programs specifically. Despite the fact that solid organ transplant recipients in particular are at increased risk of infections from multidrug-resistant organisms, due to host and donor factors and immunosuppressive therapy, there currently are little rigorous data regarding stewardship practices in solid organ transplant populations, and thus, no transplant-specific requirements currently exist. Further complicating matters, transplant patients have a wide range of variability regarding their susceptibility to infection, as factors such as surgery of transplant, intensity of immunosuppression, and presence of drains or catheters in situ may modify the risk of infection. As such, it is not feasible to have a "one-size-fits-all" style of stewardship for this patient population. The objective of this white paper is to identify opportunities, risk factors, and ASP strategies that should be assessed with solid organ transplant recipients to optimize antimicrobial use, while producing an overall improvement in patient outcomes. We hope it may serve as a springboard for development of future guidance and identification of research opportunities.

OUP accepted manuscript

The National Antimicrobial Prescribing Survey (NAPS) is a web-based qualitative auditing platform that provides a standardized and validated tool to assist hospitals in assessing the appropriateness of antimicrobial prescribing practices. Since its release in 2013, the NAPS has been adopted by all hospital types within Australia, including public and private facilities, and supports them in meeting the national standards for accreditation. Hospitals can generate real-time reports to assist with local antimicrobial stewardship (AMS) activities and interventions. De-identified aggregate data from the NAPS are also submitted to the Antimicrobial Use and Resistance in Australia surveillance system, for national reporting purposes, and to strengthen national AMS strategies. With the successful implementation of the programme within Australia, the NAPS has now been adopted by countries with both well-resourced and resource-limited healthcare systems. We provide here a narrative review describing the experience of users utilizing the NAPS programme in Canada, Malaysia and Bhutan. We highlight the key barriers and facilitators to implementation and demonstrate that the NAPS methodology is feasible, generalizable and translatable to various settings and able to assist in initiatives to optimize the use of antimicrobials.

Risk Factors for Clostridioides Difficile Diarrhea In Solid Organ Transplantation Recipients

BACKGROUND

There is limited knowledge about risk factors for Clostridioides difficile infection (CDI) and recurrent CDI in solid organ transplant (SOT) recipients.

METHODS

A case-control study of CDI in SOT recipients compared with controls (SOT recipients who did not present CDI).

RESULTS

Sixty-seven patients from 1089 SOT recipients (6.2%) suffered at least one episode of CDI. The mean age was 55 ± 12 years and 20 cases (69%) were men. The accumulated incidence was 8% in liver transplantation, 6.2% in lung transplantation, 5.4% in heart transplantation, and 4.7% in kidney transplantation. Twenty-nine cases (43.3%) were diagnosed during the first 3 months after SOT. Forty-one cases (61.2%) were hospital acquired. Thirty-one patients with CDI presented with mild-moderate infection (46.3%), 30 patients with severe infection (44.8%), and 6 patients with severe-complicated disease (9%). Independent variables found to be related with CDI were hospitalization in the previous 3 months (odds ratio: 2.99; [95% confidence interval 1.21-7.37]) and the use of quinolones in the previous month (odds ratio: 3.71 [95% confidence interval 1.16-11.8]). Eleven patients (16.4%) had at least one recurrence of CDI. Previous treatment with amoxicillin-clavulanate, severe-complicated index episode, and high serum creatinine were associated with recurrent CDI in the univariant analysis CONCLUSIONS: Liver transplant recipients presented the highest incidence of CDI among SOT recipients. Risk factors for CDI were hospitalization in the previous 3 months and the use of quinolones in the previous month.

The time is now: antimicrobial stewardship in solid organ transplantation

PURPOSE OF REVIEW

To provide a summary of complications of antimicrobials and opportunities for antimicrobial stewardship (AS) in solid organ transplant (SOT) patient care.

RECENT FINDINGS

Personalized, precision antimicrobial prescribing in SOT aiming to avoid negative consequences of antimicrobials is essential to improving patient outcomes. The positive impact AS efforts in transplant care has been recognized and bespoke activities tailored to special interests of transplant patients and providers are evolving. Strategies to optimize stewardship interventions targeting antibacterial, antiviral, and antifungal drug selection and dosing in the transplant population have been recently published though clinical integration using a 'handshake' stewardship model is an optimal starting point in transplant care. Other recent studies involving transplant recipients have identified opportunities to shorten duration or avoid antimicrobials for certain commonly encountered clinical syndromes. This literature, informing recent consensus clinical practice guidelines, may help support institutional practice guidelines and protocols. Proposals to track and report stewardship process and outcome measures as a routine facet of programmatic transplant quality reporting have been published. However, developing novel metrics accounting for nuances of transplant patients and programs is critical. Important studies are needed to evaluate organizational transplant prescribing cultures and optimal behavioral science-based interventions relevant to antimicrobial use in this population.

SUMMARY

Consequences of antimicrobial use, such as drug toxicities, and Clostridiodes difficile (CDI) and multidrug-resistant organisms colonization and infection disproportionately affect SOT recipients and are associated with poor allograft and patient outcomes. Stewardship programs encompassing transplant patients aim to personalize antimicrobial prescribing and optimize outcomes. Further studies are needed to better understand optimal intervention strategies in SOT.

The use of automated data extraction tools to develop a solid organ transplant registry: Proof of concept study of bloodstream infections

BACKGROUND

We created an electronic health record-based registry using automated data extraction tools to study the epidemiology of bloodstream infections (BSI) in solid organ transplant recipients. The overarching goal was to determine the usefulness of an electronic health record-based registry using data extraction tools for clinical research in solid organ transplantation.

METHODS

We performed a retrospective single-center cohort study of adult solid organ transplant recipients from 2010 to 2015. Extraction tools were used to retrieve data from the electronic health record, which was integrated with national data sources. Electronic health records of subjects with positive blood cultures were manually adjudicated using consensus definitions. One-year cumulative incidence, risk factors for BSI acquisition, and 1-year mortality were analyzed by Kaplan-Meier method and Cox modeling, and 30-day mortality with logistic regression.

RESULTS

In 917 solid organ transplant recipients the cumulative incidence of BSI was 8.4% (95% confidence interval 6.8-10.4) with central line-associated BSI as the most common source. The proportion of multidrug-resistant isolates increased from 0% in 2010 to 47% in 2015 (p = 0.03). BSI was the strongest risk factor for 1-year mortality (HR=8.44; 4.99-14.27; p<0.001). In 11 of 14 deaths, BSI was the main cause or contributory in patients with non-rapidly fatal underlying conditions.

CONCLUSIONS

Our study illustrates the usefulness of an electronic health record-based registry using automated extraction tools for clinical research in the field of solid organ transplantation. A BSI reduces the 1-year survival of solid organ transplant recipients. The most common sources of BSIs in our studies are preventable.

Impact of an antimicrobial stewardship program in the antimicrobial-resistant and prevalence of clostridioides difficile infection and amount of antimicrobial consumed in cancer patients

OBJECTIVE

The The impact of a hospital antimicrobial stewardship was determined on antimicrobial-resistant, Clostridioides difficile rates and the amount of antimicrobial consumed in cancer patients.The intervention effects of antimicrobial stewardship (ASP) plans in 2017-2018 and 2018-2019 were respectively evaluated among hematology/oncology and bone marrow transplant patients in Ayatollah Taleghani University Hospital, Tehran, Iran. In this interventional quasi-experimental study, the ASP repository was utilized to capture four survey questions encompassed in these immunocompromised patients: amount of antibiotics (meropenem and vancomycin) consumption gr-year, the number of positive Clostridioides difficile infection and multidrug-resistant positive cases in blood cultures.

RESULTS

The number of MDR cases in the periods of 2017-2018 and 2018-2019 were 145 and 75, respectively (p = 0.011). A significant reduction in all positive blood cultures from 2017-2018 to 2018-2019 was found (p = 0.001). 574 patients admitted to our hospital in these periods of 2017- 2018 and 2018- 2019were assessed for MPM and VMN use. The amounts of MPM prescriptions in 2018-2019 was significantly decreased from 22464 to 17262 g (p = 0.043). The significant reduction in antibiotic consumption, MDR organisms, and CDI can highly promote patients' health and decreasing medical costs and long-term defects for patients.

How can we optimise antifungal use in a solid organ transplant centre? Local epidemiology and antifungal stewardship implementation: A single-centre study

PURPOSE

We aimed to implement and to assess the impact of the antifungal stewardship programme (AFSp) on prescription appropriateness of antifungals, management and outcomes of candidaemia patients, and antifungal consumption and costs at our solid organ transplant (SOT) institute.

METHODS

Local epidemiology of invasive fungal infections (IFIs) from 2009 to 2017 was analysed in order to prepare an effective AFSp, implemented in January 2018. It included suspension of empirical antifungal prescriptions after 72 hours (antifungal time-out), automated alert and infectious disease (ID) consult for empirical prescriptions and for every patient with IFI, and indication for step-down to oral fluconazole when possible. We used process measures and results measures to assess the effects of the implemented programme.

RESULTS

The ASFp led to significant improvements in selection of the appropriate antifungal (40.5% in pre-AFS vs 78.6% in post-AFS), correct dosing (51.2% vs 79.8%), correct length of treatment (55.9% vs 75%) and better management of patients with candidaemia. Analysis of prescribed empirical antifungal revealed that defined daily doses (DDDs) per 100 patient days decreased by 36.7% in 2018 compared to the average of pre-AFSp period, with important savings in costs.

CONCLUSION

This AFSp led to a better use of antifungal drugs in terms of appropriateness and consumption, with stable clinical and microbiological outcomes in patients with IFI.

Antimicrobial stewardship in transplant patients

PURPOSE OF REVIEW

To provide an update on the current landscape of antimicrobial stewardship in solid organ transplant (SOT) recipients.

RECENT FINDINGS

Constructing personalized antimicrobial prescribing approaches to avoid untoward consequences of antimicrobials while improving outcomes is an emerging and critical aspect of transplant medicine. Stewardship activities encompassing the specialized interests of transplant patients and programs are evolving. New literature evaluating strategies to optimize antimicrobial agent selection, dosing, and duration have been published. Additionally, consensus guidance for certain infectious clinical syndromes is available and should inform institutional clinical practice guidelines. Novel metrics for stewardship-related outcomes in transplantation are desperately needed. Though exciting new molecular diagnostic technologies will likely be pivotal in the care of immunocompromised patients, optimal clinical adaptation and appropriate integration remains unclear. Important studies understanding the behaviors influencing antimicrobial prescribing in organizational transplant cultures are needed to optimize interventions.

SUMMARY

Consequences of antimicrobial use, such as Clostridiodes difficile and infections with multidrug-resistant organisms disproportionately affect SOT recipients and are associated with poor allograft and patient outcomes. Application of ASP interventions tailored to SOT recipients is recommended though further studies are needed to provide guidance for best practice.

Finding the relevance of antimicrobial stewardship for cystic fibrosis

Antimicrobials have undoubtedly improved the lives of people with CF, but important antimicrobial-related toxicities and the emergence of antimicrobial-resistant bacteria associated with their use must be considered. Antimicrobial stewardship (AMS) is advocated across the spectrum of healthcare to promote the appropriate use of antimicrobials to preserve their current effectiveness and to optimise treatment, and it is clear that AMS strategies are applicable to and can benefit both non-CF and CF populations. This perspective explores the definition and components of an AMS program, the current evidence for AMS, and the reasons why AMS is a challenging concept in the provision of CF care. We also discuss the elements of CF care which align with AMS programs and principles and propose research priorities for AMS in CF.

Challenges in the Diagnosis and Management of Bacterial Lung Infections in Solid Organ Recipients: A Narrative Review

Respiratory infections pose a significant threat to the success of solid organ transplantation, and the diagnosis and management of these infections are challenging. The current narrative review addressed some of these challenges, based on evidence from the literature published in the last 20 years. Specifically, we focused our attention on (i) the obstacles to an etiologic diagnosis of respiratory infections among solid organ transplant recipients, (ii) the management of bacterial respiratory infections in an era characterized by increased antimicrobial resistance, and (iii) the development of antimicrobial stewardship programs dedicated to solid organ transplant recipients.

Surveillance of common infections in the early period after renal transplantation in a national center: 2014-2017

BACKGROUND

Infection prevention and timely and effective treatment are among the major aims of care in kidney transplant recipients. Pre-transplant vaccination and pre-transplant viral screening have been extensively studied and are now considered standard practice. Early post-operative infection surveillance is mandatory in other vulnerable cohorts, but has not been extensively studied in this population. We hypothesized that surveillance of the most common bacterial infection types in the post-transplant setting would be beneficial and identify key areas for improvement.

METHODS

All adult kidney transplant recipients whose surgeries were performed in the Irish national kidney transplant unit over a 1-year period had prospective early post-transplant (first 30 days) infection surveillance in 2014 for surgical site infection, urinary tract infection, and secondary bloodstream infections (Group T0). Several key changes were implemented following scrutiny of infection patterns and clinical practice. Subsequently, infection surveillance was undertaken for 2016 and 2017 (Group T1) to assess the impact of these changes.

RESULTS

Between 2014 and 2017, the number of kidney transplants increased by 32%. The following aspects of clinical practice were the focus of change following analysis of Group T0 data: timing of surgical antimicrobial prophylaxis (SAP) administration, choice of SAP antimicrobial agent, and routine microbiological testing in the peri-operative period. Following implementation of these changes, the timing of SAP administration was greatly improved (45%-100% of cases appropriately timed). The infection rate decreased from 8.9% to 7.4% in 2016, with a further decrease to 4% in 2017 (OR 0.42 (95% CI: 0.16-1.10); P = .08). Compliance with pre-operative microbiological screening improved in Group T1.

CONCLUSIONS

Simple clinical practice changes, implemented upon analysis of common bacterial infection surveillance data in the first 30 days after kidney transplantation resulted in more effective SAP administration and improved compliance with routine microbiological testing in the peri-operative period. These interventions have potentially contributed to reduced early post-operative infection rates, despite increased transplant activity in the unit. Infection surveillance is an important and under-utilized way of reducing infections in this vulnerable patient cohort.

Pre- and post-transplant bacterial infections in liver transplant recipients

BACKGROUND

Early (<1 month) bacterial infection after liver transplant is a major cause of morbidity and mortality among liver transplant recipients. We investigated the impact of pre-transplant bacterial infection on early post-transplant bacterial infection incidence and outcomes.

METHODS

A retrospective cohort study identified all patients who underwent liver transplantation between January 1, 2011, and December 31, 2012, at a single tertiary center in the United States. Infections occurring within the 30 days prior to transplant and within the 30 following transplant were identified. Information regarding pre-transplant morbidity and post-transplant outcomes was collected.

RESULTS

One-hundred seventy-four patients were included in the study. Forty patients (23%) experienced a total of 50 pre-transplant infections. Fifty-two (30%) developed a total of 62 post-transplant infections. Patients with a pre-transplant infection were more likely to develop a post-transplant infection compared to patients without a pre-transplant infection (48% [19 of 40] vs. 25% [33 of 134], respectively, P = .006). Patients with a pre-transplant infection had a longer mean post-transplant length of stay compared to those without a pre-transplant infection (16.3 days vs. 10.4 days, respectively, P < .001), but survival at 30 days was similar in both groups (95% [38 of 40] vs. 97% [130 of 134, respectively, P = .56).

CONCLUSIONS

Among liver transplant recipients, pre-transplant infection is an important risk factor for early post-transplant bacterial infections. Pre-transplant infection is associated with increased early morbidity but not mortality after transplant.

Multidrug-resistant Gram-negative bacterial infections in solid organ transplant recipients-Guidelines from the American Society of Transplantation Infectious Diseases Community of Practice

These updated guidelines from the Infectious Diseases Community of Practice of the American Society of Transplantation review the diagnosis, prevention, and management of infections due to multidrug-resistant (MDR) Gram-negative bacilli in the pre- and post-transplant period. MDR Gram-negative bacilli, including carbapenem-resistant Enterobacteriaceae, MDR Pseudomonas aeruginosa, and carbapenem-resistant Acinetobacter baumannii, remain a threat to successful organ transplantation. Clinicians now have access to at least five novel agents with activity against some of these organisms, with others in the advanced stages of clinical development. No agent, however, provides universal and predictable activity against any of these pathogens, and very little is available to treat infections with MDR nonfermenting Gram-negative bacilli including A baumannii. Despite advances, empiric antibiotics should be tailored to local microbiology and targeted regimens should be tailored to susceptibilities. Source control remains an important part of the therapeutic armamentarium. Morbidity and mortality associated with infections due to MDR Gram-negative organisms remain unacceptably high. Heightened infection control and antimicrobial stewardship initiatives are needed to prevent these infections, curtail their transmission, and limit the evolution of MDR Gram-negative pathogens, especially in the setting of organ transplantation.

Antimicrobial stewardship by academic detailing improves antimicrobial prescribing in solid organ transplant patients

We implemented twice-weekly academic detailing rounds in 2015 as an antimicrobial stewardship (AMS) intervention in solid organ transplant (SOT) patients, led by an AMS pharmacist and a transplant infectious diseases physician. They reviewed SOT patients' antimicrobials and made recommendations to prescribers on antimicrobial regimens, diagnostics investigations, and appropriate referrals for transplant infectious diseases consultation. To determine the impact of the intervention, we adjudicated antimicrobials prescriptions using established AMS principles, and compared the proportion of AMS-concordance regimens pre-intervention (2013) with post-intervention (2016) via 4-point-prevalence surveys conducted in each period. All admitted SOT patients who were receiving antimicrobial treatment on survey days were included. Primary outcome was the percentage of antimicrobial regimen adjudicated as AMS concordant. Secondary outcomes were percentage of AMS concordance in patients consulted by transplant infectious diseases; categories of AMS discordance; antimicrobial consumption in defined daily dose/100 patient-days (DDD/100PD); antimicrobial cost in CAD$/PD; and C. difficile infections. Balancing measures were length of stay, 30-day readmission, and in-hospital mortality. We compared outcomes using χ² test or t-test; significant difference was defined as p < 0.05. Pre-intervention surveys included 139 patients, post-intervention, 179 patients, with 62.3% vs. 56.6% receiving antimicrobials, respectively (p = 0.27). AMS concordance increased from 69% (60/87) to 83.7% (93/111), p = 0.01. Not tailoring antimicrobials was the most common discordance category. AMS concordance under transplant infectious diseases was 82.5% (33/40) pre-intervention vs. 76.6% (36/47) post-intervention, p = 0.5. Antimicrobial consumption increased by 15.3% (140.9 vs.162.4 DDD/100PD, p = 0.001). Antimicrobial cost, C. difficile infection rates and balancing measures remained stable. Academic detailing increased appropriate antimicrobial use in SOT patients without untoward effects.

Infectious complications in the Southern Tasmanian kidney transplant population

AIM

Examine the incidence of suspected and proven infections, the range of infections, antimicrobial use and hospital admissions in kidney transplant recipients (KTx) in southern Tasmania.

METHODS

An audit of the medical records of KTx managed by the Royal Hobart Hospital for the period 1 January 2015 to 31 December 2016. Data were collected on positive microbiological investigations, antimicrobial use and hospital admissions.

RESULTS

Of the 151 evaluable KTx, there were 339 episodes of suspected infection in 95 (63%) patients with a preponderance of urinary tract infections. Overall, these 95 KTx received a total of 249 courses of antimicrobials, with predominantly monotherapy (n = 101, 65%). There were 11 vaccine preventable infections, including herpes zoster (n = 7), Influenza A (n = 3) and invasive pneumococcal disease (n = 1). Hospitalization was required for 50 infectious episodes, for a total of 227 admitted bed days (median 4; interquartile range 2-7; range 1-18 days).

CONCLUSION

In conclusion, episodes of infection, hospitalization, antimicrobial use and development of multi-resistant organisms are common following kidney transplantation in this southern Tasmanian cohort. This study has identified several areas of focus for improved patient care including antimicrobial management of urinary tract infections, implementation of programmes to vaccinate KTx prior to transplantation, and development of transplantation specific antimicrobial stewardship programmes.

Principles and Practice of Antibiotic Stewardship in the ICU

In the face of emerging drug-resistant pathogens and a decrease in the development of new antimicrobial agents, antibiotic stewardship should be practiced in all critical care units. Antibiotic stewardship should be a core competency of all critical care practitioners in conjunction with a formal antibiotic stewardship program (ASP). Prospective audit and feedback, and antibiotic time-outs, are effective components of an ASP in the ICU. As rapid diagnostics are introduced in the ICU, assessment of performance and effect on outcomes will clearly be needed. Disease-specific stewardship for community-acquired pneumonia that relies on clinical pathways may be particularly high-yield. Computerized decision support has the potential to individualize stewardship for specific patients. Finally, infection control and prevention is the cornerstone of every ASP.

Strategies for Antimicrobial Stewardship in Solid Organ Transplant Recipients

Complications of antimicrobial therapy, such as multidrug-resistant organisms and Clostridium difficile, commonly affect solid-organ transplant recipients and have been associated with graft loss and mortality. Although opportunities are abundant, antimicrobial stewardship practices guiding appropriate therapy have been infrequently reported in transplant patients. A patient-centered, multidisciplinary structure, using established antimicrobial optimization principles, is needed to create nuanced approaches to protect patients and antimicrobials and improve outcomes.

Prevention and Treatment of Clostridium difficile-Associated Diarrhea in Solid Organ Transplant Recipients

Clostridium difficile infection is a significant cause of morbidity and mortality in solid organ transplant recipients. Risk factors in this population include frequent hospitalizations, receipt of immunosuppressive agents, and intestinal dysbiosis triggered by several factors, including exposure to broad-spectrum antimicrobials. The incidence and potential for significant adverse outcomes among solid organ transplant recipients with C difficile infection highlight the evolving need for strategic C difficile infection risk factor modification and novel approaches to disease management in this patient population. This review focuses on current concepts related to the prevention and treatment of C difficile infection in solid organ transplant recipients.

Management of bacterial and fungal infections in end stage liver disease and liver transplantation: Current options and future directions

Patients with liver cirrhosis are susceptible to infections due to various mechanisms, including abnormalities of humoral and cell-mediated immunity and occurrence of bacterial translocation from the intestine. Bacterial infections are common and represent a reason for progression to liver failure and increased mortality. Fungal infections, mainly caused by Candida spp., are often associated to delayed diagnosis and high mortality rates. High level of suspicion along with prompt diagnosis and treatment of infections are warranted. Bacterial and fungal infections negatively affect the outcomes of liver transplant candidates and recipients, causing disease progression among patients on the waiting list and increasing mortality, especially in the early post-transplant period. Abdominal, biliary tract, and bloodstream infections caused by Gram-negative bacteria [e.g., Enterobacteriaceae and Pseudomonas aeruginosa (P. aeruginosa)] and Staphylococcus spp. are commonly encountered in liver transplant recipients. Due to frequent exposure to broad-spectrum antibiotics, invasive procedures, and prolonged hospitalizations, these patients are especially at risk of developing infections caused by multidrug resistant bacteria. The increase in antimicrobial resistance hampers the choice of an adequate empiric therapy and warrants the knowledge of the local microbial epidemiology and the implementation of infection control measures. The main characteristics and the management of bacterial and fungal infections in patients with liver cirrhosis and liver transplant recipients are presented.

Characterization of Potentially Unsafe Ambulatory Antibiotic Use and Associated Outcomes in an Adult Kidney Transplant Population

BACKGROUND

Antibiotics are frequently prescribed to kidney transplant (KTX) recipients in the outpatient setting, but there are limited data assessing the safety and outcomes associated with this practice.

OBJECTIVE

The primary objective of this study was to describe ambulatory antibiotic prescribing in a large cohort of adult KTX recipients. The secondary objective was to assess the outcomes associated with potentially unsafe antibiotic use in this population.

METHODS

National Veterans Health Administration data compiled between 2001 and 2010 were used to conduct a pharmacovigilance assessment of antibiotic prescribing, excluding intravenous agents, antifungals, antivirals, and prophylactic regimens. Multivariable Cox proportional hazard regression was used to determine the impact of safe and potentially unsafe antibiotic use on time to event for graft loss.

RESULTS

Among 5130 KTX recipients and 30 127 patient-years of follow-up, 14 259 antibiotic courses were prescribed at a rate of 0.47 courses per patient-year. Transplant or nephrology providers prescribed 24.8% of courses. Overall, 608 courses (4.3%) in 311 patients (6.1%) were considered potentially unsafe for dosages in disagreement with recommended adjustments for renal function, interaction with immunosuppressive regimens, and other pertinent safety concerns. After adjusting for baseline characteristics, unsafe antibiotic use was associated with a 40% higher risk of graft loss (adjusted hazard ratio = 1.40; 95% CI = 1.03-1.89; P = 0.030) compared with safe use.

CONCLUSIONS AND RELEVANCE

Although unsafe antibiotic prescribing was uncommon, it was associated with increased risk of graft loss. Prospective research is needed to elucidate whether the driver of poor outcomes is the safety of the antibiotic prescription or fragmented care.

Stewardship opportunities in viral pneumonia: Why not the immunocompromised?

Antimicrobial management of viral pneumonia has proven to be a challenge in hospitalized immunocompromised patients. A host of factors contribute to the dilemma, such as diagnostic uncertainty, lack of organism identification, and clinical status of the patient. Respiratory virus panel (RVP) use was compared between 131 immunocompromised patients who received send‐out (n = 56) vs in‐house (n = 75) testing. Antimicrobial optimization interventions consisted of antiviral addition/discontinuation, antibiotic discontinuation/de‐escalation, or modification of immunosuppressive regimen. After implementation of an in‐house test with audit and feedback, turnaround time of the RVP was reduced from 46.7 to 5.5 hours (P < .001) and time to intervention was reduced from 52.1 to 13.9 hours (P < .001), yet the frequency of antimicrobial optimization interventions was unchanged (30.7% vs 35.7%). Differences were not observed in duration of empiric antibiotic therapy or length of stay. The overall discontinuation rate for patients tested with a RVP was low (4.6%), and those with positive RVP (n = 43) had antibiotics stopped in 14% of cases. Bacterial pneumonia coinfection was confirmed in 2 patients. Further systematic efforts should be taken to reduce antibiotic use in viral pneumonia and identify the major barriers in the immunocompromised population.

Feasibility and applicability of antimicrobial stewardship in immunocompromised patients

PURPOSE OF REVIEW

Antimicrobial stewardship is the primary intervention in the battle against antimicrobial resistance, but clinicians do not always apply many key antimicrobial stewardship principles to patients with significant immune defects due to lack of data and fear of bad outcomes. We review evidence regarding the application of stewardship principles to immunocompromised patients, with a focus on solid organ and hematopoietic stem cell transplant recipients.

RECENT FINDINGS

Antimicrobial stewardship programs (ASPs), targeting immunocompromised patient populations such as oncology and transplant, are gaining traction. Emerging literature suggests that several stewardship interventions can be adapted to immunocompromised hosts and improve antimicrobial utilization, but data supporting improved outcomes is very limited.

SUMMARY

The application of antimicrobial stewardship principles to immunocompromised patients is feasible, necessary, and urgent. As antimicrobial stewardship programs gain momentum across a diverse range of healthcare settings more immunocompromised patients will fall under their purview. It is imperative that centers applying antimicrobial stewardship principles share their experience and establish collaborative research efforts to advance our knowledge base in applying antimicrobial stewardship initiatives to immunocompromised host populations, both in terms of programmatic success and patient outcomes.

Urinary tract infections caused by ESBL-producing Enterobacteriaceae in renal transplant recipients: A systematic review and meta-analysis

BACKGROUND

Urinary tract infections (UTIs) are the most common infectious complications among renal transplant recipients (RTR). UTIs caused by extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae (ESBL-PE) have been associated with inferior clinical outcomes and increased financial burden.

METHODS

We performed a systematic review and meta-analysis by searching through the PubMed and EMBASE databases (to May 20, 2016) and identifying studies that reported data on the number of RTR who developed an ESBL-PE UTI.

RESULTS

Our analysis included seven studies, out of 357 non-duplicate articles, that provided data on 2824 patients. Among them, 10% (95% confidence interval [CI] 4%-17%) developed an ESBL-PE UTI over their follow-up periods. The proportion of RTR affected by an ESBL-PE UTI was 2% in North America (95% CI 1%-3%), 5% in Europe (95% CI 4%-6%), 17% in South America (95% CI 10%-27%), and 33% in Asia (95% CI 27%-41%). In addition, patients affected with an ESBL-PE UTI were 2.75-times (95% CI 1.97-3.83) more likely to suffer a recurrent UTI.

CONCLUSIONS

Based on a limited number of studies, one in 10 RTR will develop a UTI caused by an ESBL-PE, and these patients face an almost 3 times greater risk of recurrence. A more rigorous monitoring of RTR, both during and after resolution of their infection, should be evaluated in order to reduce the incidence and the clinical impact of these resistant infections.

Clostridium difficile infection in solid organ transplant recipients

PURPOSE OF REVIEW

Clostridium difficile infection (CDI) is a major healthcare-associated infection that causes significant morbidity and an economic impact in the United States. In this review, we provide an overview of Clostridium difficile infection in solid organ transplant recipients with an emphasis on recent literature.

RECENT FINDINGS

C. difficile in solid organ transplant population has unique risk factors. Fecal microbiota transplantation has shown favorable results in treatment of recurrent C. difficile in this population. Preliminary data from animal studies suggests excellent efficacy with immunization against C. difficile toxins.

SUMMARY

Over the last decade, number of individuals receiving solid organ transplants has increased exponentially making peri-transplant complications a common occurrence.C. difficile is a frequent cause of morbidity in solid organ transplant recipients. Early and accurate diagnosis of C. difficile requires a stepwise approach. Differentiating between asymptomatic carriage and infection is a diagnostic challenge. Microbial diversity is inversely proportional to risk of C. difficile infection. Antimicrobial stewardship programs help to retain microbial diversity in individuals susceptible to CDI. Recurrent or relapsing C. difficile infection require fecal microbiota transplantation for definitive cure.

Colonization with extended-spectrum beta-lactamase-producing Enterobacteriaceae in solid organ transplantation: A meta-analysis and review

BACKGROUND

Extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-E) may cause severe infections, often preceded by ESBL-E gastrointestinal (GI) colonization.

METHODS

We conducted a review of the literature, investigating the prevalence of ESBL-E GI colonization in solid organ transplant (SOT) patients and the risk for subsequent ESBL-E infection. We searched the PubMed and EMBASE databases (to April 1, 2016) looking for studies that contained data on ESBL-E colonization among transplant patients.

RESULTS

Of 341 non-duplicate citations, four studies reporting data on 1089 patients fulfilled our inclusion criteria. Among them, the pooled prevalence for ESBL-E colonization was 18% (95% confidence interval [CI] 5%-36%). Stratifying by transplant type, we identified an ESBL-E colonization rate of 17% (95% CI 3%-39%) among liver transplant recipients and 24% (single report) among kidney transplant recipients.

CONCLUSIONS

Among SOT patients, approximately one in five patients is colonized with ESBL-E, although this finding may be skewed by reporting bias from centers with high ESBL-E prevalence. ESBL-E screening in SOT patients should be considered and evaluated in future studies.

Multidrug-resistant organisms in liver transplant: Mitigating risk and managing infections

Liver transplant (LT) recipients are vulnerable to infections with multidrug-resistant (MDR) pathogens. Risk factors for colonization and infection with resistant bacteria are ubiquitous and unavoidable in transplantation. During the past decade, progress in transplantation and infection prevention has contributed to the decreased incidence of infections with methicillin-resistant Staphylococcus aureus. However, even in the face of potentially effective antibiotics, vancomycin-resistant enterococci continue to plague LT. Gram-negative bacilli prove to be more problematic and are responsible for high rates of both morbidity and mortality. Despite the licensure of novel antibiotics, there is no universal agent available to safely and effectively treat infections with MDR gram-negative organisms. Currently, efforts dedicated toward prevention and treatment require involvement of multiple disciplines including transplant providers, specialists in infectious diseases and infection prevention, and researchers dedicated to the development of rapid diagnostics and safe and effective antibiotics with novel mechanisms of action. Liver Transplantation 22 1143-1153 2016 AASLD.