Management of Clostridioides (formerly Clostridium) difficile infection (CDI) in solid organ transplant recipients: Guidelines from the American Society of Transplantation Community of Practice

Clostridioides difficile infection: history, epidemiology, risk factors, prevention, clinical manifestations, treatment, and future options

SUMMARYClostridioides difficile infection (CDI) is one of the major issues in nosocomial infections. This bacterium is constantly evolving and poses complex challenges for clinicians, often encountered in real-life scenarios. In the face of CDI, we are increasingly equipped with new therapeutic strategies, such as monoclonal antibodies and live biotherapeutic products, which need to be thoroughly understood to fully harness their benefits. Moreover, interesting options are currently under study for the future, including bacteriophages, vaccines, and antibiotic inhibitors. Surveillance and prevention strategies continue to play a pivotal role in limiting the spread of the infection. In this review, we aim to provide the reader with a comprehensive overview of epidemiological aspects, predisposing factors, clinical manifestations, diagnostic tools, and current and future prophylactic and therapeutic options for C. difficile infection.

Clostridioides difficile Infection in Kidney Transplant Recipients

Clostridioides difficile (C. difficile) is a bacterial organism that typically infects the colon, which has had its homeostasis of healthy gut microbiota disrupted by antibiotics or other interventions. Patients with kidney transplantation are a group that are susceptible to C. difficile infection (CDI) and have poorer outcomes with CDI given that they conventionally require long-term immunosuppression to minimize their risk of graft rejection, weakening their responses to infection. Recognizing the risk factors and complex pathophysiological processes that exist between immunosuppression, dysbiosis, and CDI is important when making crucial clinical decisions surrounding the management of this vulnerable patient cohort. Despite the clinical importance of this topic, there are few studies that have evaluated CDI in the context of kidney transplant recipients and other solid organ transplant populations. The current recommendations on CDI management in kidney transplant and solid organ transplant recipients are mostly extrapolated from data relating to CDI management in the general population. We provide a narrative review that discusses the available evidence examining CDI in solid organ transplant recipients, with a particular focus on the kidney transplant recipient, from the epidemiology of CDI, clinical features and implications of CDI, potential risk factors of CDI, and, ultimately, prevention and management strategies for CDI, with the aim of providing areas for future research development in this topic area.

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.

Immunological Nuances and Complications of Pediatric Organ Transplant: A Narrative Review

Organ transplantation is considered an exaggerated immune state in which the body reacts in an elaborate cascade of reactions against the lifesaving graft transplanted. Unrepairable organ damage is the main indication for a pediatric patient to undergo a transplant. The host and the donor must fulfill the criteria for a successful transplant to have as few side effects as possible. There has been much-needed research in the domain of surgery of organ transplantation, thereby extending into the pediatric age group. This article elaborates on the post-transplant management, the immuno-biochemistry aspect, and its post-surgery treatment. The post-surgery period requires great emphasis as morbidity and mortality are highest. There is much to understand about managing transplant patients to avoid complications such as infections, hypertension, or side effects of immunosuppressive drugs. The treating clinician faces the challenges of managing the dose and frequency of immuno-suppressive medicines to prevent complications in the patients. If the dose is inadequate, there are chances of graft rejection. If the immuno-suppression is prolonged, there may be chances of infections in the patient. This article aims to summarize the mechanism of graft rejection and put forth the need for further research about creating a universal protocol for managing a patient's immune system post-transplant. The authors hope this protocol will help the clinician better understand the patient's current state and help in appropriately using immuno-suppressive drugs. It calls upon the need for a reliable and easily repeatable battery of investigations that will help solve this dilemma.

Fecal Microbiota Transplant in Pediatric Solid Organ Transplant Recipients

BACKGROUND

Fecal microbiota transplant (FMT) is an effective treatment for recurrent Clostridioides difficile infection (CDI). Safety concerns around FMT are increased in immunocompromised populations, such as solid organ transplant (SOT) recipients. Outcomes among adult SOT recipients suggest FMT is efficacious and safe; however, pediatric SOT data are lacking.

METHODS

We describe the efficacy and safety of FMT among pediatric SOT recipients in a single-center retrospective study from March 2016 to December 2019. Successful FMT was defined as no recurrence of CDI within 2 mo of FMT. We identified 6 SOT recipients ages 4-18 y who received FMT a median of 5.3 y post-SOT.

RESULTS

Success after a single FMT was 83.3%. One liver recipient did not achieve cure after 3 FMTs and remains on low-dose vancomycin. One serious adverse event (SAE) occurred; cecal perforation and bacterial peritonitis occurred following colonoscopic FMT coordinated with intestinal biopsy in a kidney transplant recipient. He achieved full recovery and CDI cure. There were no other SAEs. There were no adverse events related to immunosuppression or transplantation status including: bacteremia, cytomegalovirus activation or reactivation, allograft rejection, or allograft loss.

CONCLUSIONS

In this limited series, efficacy of FMT in pediatric SOT is comparable to efficacy in the general pediatric recurrent CDI population. There may be an increased risk of procedure-related SAE in SOT patients and larger cohort studies are needed.

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.

Infections after organ transplantation and immune response

Organ transplantation has provided another chance of survival for end-stage organ failure patients. Yet, transplant rejection is still a main challenging factor. Immunosuppressive drugs have been used to avoid rejection and suppress the immune response against allografts. Thus, immunosuppressants increase the risk of infection in immunocompromised organ transplant recipients. The infection risk reflects the relationship between the nature and severity of immunosuppression and infectious diseases. Furthermore, immunosuppressants show an immunological impact on the genetics of innate and adaptive immune responses. This effect usually reactivates the post-transplant infection in the donor and recipient tissues since T-cell activation has a substantial role in allograft rejection. Meanwhile, different infections have been found to activate the T-cells into CD₄⁺ helper T-cell subset and CD₈⁺ cytotoxic T-lymphocyte that affect the infection and the allograft. Therefore, the best management and preventive strategies of immunosuppression, antimicrobial prophylaxis, and intensive medical care are required for successful organ transplantation. This review addresses the activation of immune responses against different infections in immunocompromised individuals after organ transplantation.

Antibiotic ampicillin induces immune tolerance in renal transplantation by regulating the proportion of intestinal flora in mice

Objectives

There are significant differences in the composition of intestinal flora in renal transplant recipients before and after an operation, which has a great impact on the prognosis of renal transplantation. The purpose of this project is to study the effect of intestinal flora imbalance on renal transplantation.

Methods

The animal model of renal transplantation was established after intestinal flora imbalance (mice pretreated with compound antibiotics), or the animal model of renal transplantation was established after being pretreated with single antibiotics. HE, PAS, and Masson staining was used to detecting the histopathological changes of transplanted renal. The expression of inflammatory factors and infiltration of inflammatory cells of renal tissue were respectively been detected by ELISA kit and flow cytometry.

Results

Antibiotic pretreatment restored weight loss, and decreased serum creatinine level in mice after renal transplantation. The tissue staining, ELISA assay, and flow cytometry data showed that antibiotic pretreatment alleviated injury of the renal allograft, inhibited the inflammatory factors levels, and reduced inflammatory cell infiltration in mice after renal transplantation. Furthermore, single antibiotic, especially ampicillin pretreatment can also play the same role as compound antibiotics, such as restoring weight loss, decreasing serum creatinine level, alleviating renal allograft injury, inhibiting inflammatory factors levels, and reducing inflammatory cell infiltration in mice after renal transplantation.

Conclusions

Antibiotic ampicillin may inhibit inflammatory cell infiltration after renal transplantation by regulating the proportion of intestinal flora in mice, to reduce renal injury and play a role in renal protection.

Outpatient and peri-operative antibiotic stewardship in solid organ transplantation

BACKGROUND

The consequences of inappropriate antimicrobial use including resistance are increasingly recognized as a global public health threat and many steps have been taken over the last few decades to advance antimicrobial stewardship initiatives with most organ transplant centers currently part of institutions with active antimicrobial stewardship programs.

METHODS

A review of the literature was conducted and articles were categorized according to the topic and relevance in the judgment of the two authors.

RESULTS

A summary review of the currently available literature was created with a focus on periprocedural and outpatient antimicrobial stewardship. Limitations in the data were significant and discussed in the review.

CONCLUSION

The principles of antimicrobial stewardship remain important throughout all phases starting with periprocedural prophylactic antimicrobial selection all the way through to discharge and subsequent healthcare encounters. Despite the broad advances in stewardship initiatives and the rapidly progressing supportive data overall there continue to be significant opportunities for additional research within various special patient populations including recipients of solid organ transplantation (SOT). The recent white paper published in the American Journal of Transplantation called to action the transplant and stewardship communities to have an increased focus and awareness of the issues that antimicrobial overuse can present in the SOT patient population. This is an important step that will hopefully generate more data in this group of patients that arguably faces the greatest vulnerability to the consequences of increased antimicrobial resistance.

Systematic review of guidelines for the diagnosis and treatment of Clostridioides difficile infection

Objective

To systematically assess the current related methodological quality of guidelines for the diagnosis and treatment of Clostridioides difficile infection (CDI), revealing the heterogeneity and reasons for guideline recommendations for the diagnosis and treatment of CDI.

Methods

We searched electronic databases systematically between 2017 and 2021 to find the latest guidelines for the diagnosis and treatment of CDI. The Appraisal of Guidelines for Research and Evaluation (AGREE II) tool was used for quality assessment of the included guidelines. The main recommendations for the diagnosis and treatment of CDI in the guidelines were extracted and evaluated for consistency, and the level of evidence supporting these recommendations was further extracted and analysed.

Results

Fourteen guidelines for the diagnosis and treatment of CDI were finally included in this study. There were four guidelines, BSG and HIS, ASCRS, IDSA AND SHEA, and NICE, with an overall score of more than 60%, which is worthy of clinical recommendation. Further analysis of the consistency of the main recommendations for the diagnosis and treatment of CDI in the guidelines showed that the recommendations differed among guidelines. There are no unified classification criteria for the severity of CDI in current studies; some recommendations for the diagnosis and treatment of CDI do not provide evidence to support the recommendations, most recommendations cite low levels of evidence, and there is a lack of high-quality research evidence.

Conclusion

The quality of guidelines for the diagnosis and treatment of CDI is uneven. Recommendations on the diagnosis and treatment of CDI have also varied in the guidelines for the past 5 years. Improvements of the aforementioned factors associated with causing heterogeneity would be a rational approach by guideline developers to further update guidelines for the diagnosis and treatment of CDI.

Bring it on: Top five antimicrobial stewardship challenges in transplant infectious diseases and practical strategies to address them

Antimicrobial therapies are essential tools for transplant recipients who are at high risk for infectious complications. However, judicious use of antimicrobials is critical to preventing the development of antimicrobial resistance. Treatment of multidrug-resistant organisms is challenging and potentially leads to therapies with higher toxicities, intravenous access, and intensive drug monitoring for interactions. Antimicrobial stewardship programs are crucial in the prevention of antimicrobial resistance, though balancing these strategies with the need for early and frequent antibiotic therapy in these immunocompromised patients can be challenging. In this review, we summarize 5 frequently encountered transplant infectious disease stewardship challenges, and we suggest strategies to improve practices for each clinical syndrome. These 5 challenging areas are: asymptomatic bacteriuria in kidney transplant recipients, febrile neutropenia in hematopoietic stem cell transplantation, antifungal prophylaxis in liver and lung transplantation, treatment of left-ventricular assist device infections, and Clostridioides difficile infection in solid-organ and hematopoietic stem-cell transplant recipients. Common themes contributing to these challenges include limited data specific to transplant patients, shortcomings in diagnostic testing, and uncertainties in pharmacotherapy.

Long-Term Infectious Complications of Kidney Transplantation

Infections remain a common complication of solid-organ transplantation. Most infections in the first month after transplant are typically health care-associated infections, whereas late infections, beyond 6-12 months, are community-acquired infections. Opportunistic infections most frequently present in the first 12 months post-transplant and can be modulated on prior exposures and use of prophylaxis. In this review, we summarize the current epidemiology of postkidney transplant infections with a focus on key viral (BK polyomavirus, cytomegalovirus, Epstein-Barr virus, and norovirus), bacterial (urinary tract infections and Clostridioides difficile colitis), and fungal infections. Current guidelines for safe living post-transplant are also summarized. Literature supporting prophylaxis and vaccination is also provided.

Bacterial infections in lung transplantation

Lung transplantation has lower survival rates compared to other than other solid organ transplants (SOT) due to higher rates of infection and rejection-related complications, and bacterial infections (BI) are the most frequent infectious complications. Excess morbidity and mortality are not only a direct consequence of these BI, but so are subsequent loss of allograft tolerance, rejection, and chronic lung allograft dysfunction due to bronchiolitis obliterans syndrome (BOS). A wide variety of pathogens can cause infections in lung transplant recipients (LTRs), including a number of nosocomial pathogens and other multidrug-resistant (MDR) pathogens. Although pneumonia and intrathoracic infections predominate, LTRs are at risk of a number of types of infections. Risk factors include altered anatomy and function of airways, impaired immunity, the microbial flora of the donor and recipient, underlying medical conditions, and genetic factors. Further work on immune monitoring has the potential to improve outcomes. The infecting agents can be derived from the donor lung, pre-existing recipient flora, or acquired from the environment over time. Certain infections may preclude lung transplantation, but this varies from center to center, and more recent studies suggest fewer patients should be disqualified. New molecular methods allow microbiome studies of the lung, gut, and other sites that may further our knowledge of how airway colonization can result in infection and allograft loss. Surveillance, early diagnosis, and aggressive antimicrobial therapy of BI is critical in LTRs. Antibiotic resistance is a major barrier to successful management of these infections. The availability of new agents for MDR Gram-negatives may improve outcomes. Other new therapies, such as bacteriophage therapy, show promise for the future. Finally, it is important to prevent infections through peri-transplant prophylaxis, vaccination, and infection control measures.

Incidence and Outcomes Associated With Clostridioides difficile Infection in Solid Organ Transplant Recipients

IMPORTANCE

Little is known about the incidence and outcomes of Clostridioides difficile infection (CDI) in solid organ transplant (SOT) recipients.

OBJECTIVE

To estimate the CDI incidence and outcomes in SOT recipients.

DESIGN, SETTING, AND PARTICIPANTS

A population-based cohort study was conducted using administrative health care data for all Ontario, Canada, residents who received organ allografts from April 1, 2003, to December 31, 2017; March 31, 2020, was the end of the study period.

MAIN OUTCOMES AND MEASURES

The primary outcome was hospital admission with CDI diagnosis. The secondary outcomes included all-cause death, intensive care unit admission, acute kidney injury requiring dialysis, and fulminant CDI comprising any of the following: toxic megacolon, ileus, perforation, or colectomy. The association between short- vs long-term mortality (ie, death occurring within or after 90 days post-CDI) and the following variables was evaluated: age, sex, Deyo-Charlson Comorbidity Index, SOT type, early- vs late-onset CDI, fulminant CDI, intensive care unit admission, and acute kidney injury requiring acute dialysis.

RESULTS

Overall, 10 724 SOT recipients (6901 [64.4%] men; median age, 54 [IQR, 44-62] years) were eligible. Kidney transplant was the most common SOT type (6453 [60.2%]). The median follow-up time was 5.0 (IQR, 2.3-8.8) years, resulting in 61 987 person-years of follow-up. A total of 726 patients (6.8%) were hospitalized with CDI. The 1-year CDI incidence significantly increased in annual cohorts (ie, from 23.1; 95% CI, 12.8-41.8 per 1000 person-years in 2004 to 46.7; 95% CI, 35.0-62.3 per 1000 person-years in 2017; P = .001). Clostridioides difficile was associated with a 16.8% rate (n = 122) of 90-day mortality. In patients who underwent kidney transplant, CDI was typically late-onset (median interval, 2.2; IQR, 0.4-6.0 years) compared with recipients of other organs. Acute kidney injury requiring dialysis was significantly associated with short-term (adjusted odds ratio [aOR], 1.86; 95% CI, 1.07-3.26) and long-term (adjusted hazard ratio [aHR], 1.89; 95% CI, 1.29-2.78) mortality, and late-onset CDI was also significantly associated with a greater risk of short-term (aOR, 4.26; 95% CI, 2.51-7.22) and long-term (aHR, 2.49; 95% CI, 1.78-3.49) mortality.

CONCLUSIONS AND RELEVANCE

In this study, increasing CDI trends in annual cohorts of SOT recipients were observed. Posttransplant CDI was associated with mortality, and late-onset CDI was associated with a greater risk of death than early-onset CDI. These findings suggest that preventive strategies should not be limited to the initial months following transplantation. Comprehensive therapeutic approaches targeting acute kidney injury risk factors in SOT recipients may reduce short- and long-term post-CDI mortality.

Clostridioides difficile infection in solid organ and hematopoietic stem cell transplant recipients: A prospective multinational study

BACKGROUND

Clostridioides difficile infection (CDI) is a significant cause of morbidity and mortality in recipients of solid organ transplant (SOT) or hematopoietic stem cell transplant (HSCT). In retrospective single center analyses, severe disease and relapse are common. We undertook an international, prospective cohort study to estimate the response to physician determined antibiotic treatment for CDI in patients with SOT and HSCT.

METHODS

Adults with a first episode of CDI within the first 2 years of SOT or HSCT were enrolled. Demographics, comorbidities, and medication history were collected, and over 90 days of follow-up clinical cure, recurrences, and complications were assessed. Logistic regression was used to study associations of baseline predictors of clinical cure and recurrence. Odds ratios (ORs) and 95% confidence intervals (CIs) are cited.

RESULTS

A total of 132 patients, 81 SOT and 51 HSCT (32 allogeneic), were enrolled with a median age of 56 years; 82 (62%) were males and 128 (97%) were hospitalized at enrollment. One hundred and six (80.3%) were diagnosed by DNA assay. CDI occurred at a median of 20 days post-transplant (interquartile range, IQR: 6-133). One hundred and eight patients (81.8%) were on proton pump inhibitors; 126 patients (95.5%) received antibiotics within the 6 weeks before CDI. The most common initial CDI treatments prescribed, on or shortly before enrollment, were oral vancomycin alone (50%) and metronidazole alone (36%). Eighty-three percent (95% CI: 76, 89) of patients had clinical cure; 18% (95% CI: 12, 27) of patients had recurrent CDI; global clinical cure occurred in 65.2%. Of the 11 patients who died, two (1.5% of total) were related to CDI. In multivariable logistic regression analyses, the type of initial treatment was associated with clinical cure (p = .009) and recurrence (p = .014). A history of cytomegalovirus (CMV) after transplant was associated with increased risk of recurrence (44% with versus 13% without CMV history; OR: 5.7, 95% CI: 1.5, 21.3; p = .01).

CONCLUSIONS

Among adults who develop CDI after SOT or HSCT, despite their immunosuppressed state, the percentage with clinical cure was high and the percentage with recurrence was low. Clinical cure and recurrence varied by type of initial treatment, and CMV viremia/disease was associated with an increased risk of recurrence.

Prevalence and outcomes of Clostridioides difficile infection in liver transplant recipients

BACKGROUND AND AIM

Data are limited on whether Clostridioides difficile infection (CDI) in the first year after liver transplantation (LT) is associated with increased mortality. In an Australian setting without hypervirulent strain of C. difficile we investigated the prevalence, risk factors, and patient survival associated with CDI in LT.

METHODS

Consecutive patients who underwent deceased-donor LT from 2007 to 2017 were studied retrospectively. Prevalence and long-term outcomes of LT recipients with and without CDI were examined in the entire LT cohort. A case-control study was performed to investigate risk factors associated with CDI.

RESULTS

Six hundred and forty-nine patients underwent LT, of which 32 (4.9%) were diagnosed with CDI within the first 12 months post-LT. There was no difference in patient survival in the overall LT cohort on Kaplan-Meier analysis when stratified by CDI status (log-rank test, p = .08). Furthermore, age was the only predictor of mortality on Cox regression (hazard ratio (HR) 1.06, 95% confidence interval (CI) 1.00-1.13, p = .03). On multivariable logistic regression, rifaximin pre-LT reduced risk (odds ratio (OR) 0.22, 95% CI 0.65-0.74, p = .01) whereas antibiotics pre-LT (OR 7.02, 95% CI 1.26-39.01, p = .03) and length of hospital stay after LT (OR 1.03, 95% CI 1.01-1.06, p = .02) were associated with increased risk of CDI.

CONCLUSIONS

Within the local setting of our study, CDI within 12 months post-LT is of low severity, associated with pre-LT antibiotic exposure and longer hospital stay but no survival impact after LT. Rifaximin use pre-LT reduced the risk of CDI post-LT.

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 outcomes of Clostridioides difficile infection in inpatient liver transplant population

BACKGROUND

Chronic immunosuppression is a known cause of Clostridioides difficile, which presents with colon infection. It is associated with increased mortality and morbidity. Our aim is to determine the inpatient outcomes of liver transplant patients with Clostridioides difficile infection (CDI) and trends in the last few years.

METHODS

We utilized the national re-admission data (2010-2017) to study the outcomes of CDI in liver transplant patients. Association of C. difficile with re-admission was computed in a multivariable model adjusted for age, sex, gastrointestinal bleeding, hypertension, diabetes, hyperlipidemia, congestive heart failure, cerebrovascular disease, obesity, cancer, insurance, chronic kidney disease, chronic obstructive pulmonary disease, dementia, peripheral vascular disease, smoking, hospital location, and teaching status.

RESULTS

During 2010-2017, there were 310 222 liver transplant patients hospitalized. Out of these, 9826 had CDI. CDI infection in liver transplant patients was associated with higher 30-day re-admission (14.3% vs. 11.21%, hazard ratio [HR]: 1.14, 95% confidence interval [CI]: 1.01-1.28, p = .02) and in-hospital mortality (odds ratio [OR]: 1.36, 95% CI: 1.14-1.61, p < .001). The most common causes of re-admission in the CDI group were recurrent CDI (41.1%), liver transplant complications (16.5%), and sepsis (11.6%). The median cost for liver transplant patients with C. difficile was significantly higher, $53 064 (IQR $24 970-$134 830) compared to patients that did not have C. difficile, $35 703 ($18 793-$73 871) (p < .001). The median length of stay was also longer for patients with CDI, 6 days (4-14) vs. 4 days (2-7) (p < .001).

CONCLUSION

CDI in post-liver transplant patients was associated with higher mortality, re-admission, health care cost, and longer length of stay. The most common cause of re-admission was recurrent CDI, which raises the question of the efficacy of standard first-line therapy.

Early Clostridioides difficile infection characterizations, risks, and outcomes in allogeneic hematopoietic stem cell and solid organ transplant recipients

BACKGROUND

Clostridioides difficile infection (CDI) frequently complicates allogeneic hematopoietic stem cell (allo-HCT) and solid organ transplantation (SOT).

METHODS

We retrospectively analyzed risk factors and outcomes of CDI occurring within 30 days of transplant.

RESULTS

Between March 2010 and June 2015, 466 allo-HCT and 1454 SOT were performed. The CDI cumulative incidence (95% CI) was 10% (8-13) and 4% (3-5), following allo-HCT and SOT, respectively (p < .01), occurring at a median (range) 7.5 days (1-30) and 11 (1-30), respectively (p = .18). In multivariate analysis, fluoroquinolones use within 14 days pre-transplantation was a risk factor for CDI following allo-HCT (HR 4.06 [95% CI 1.31-12.63], p = .02), and thoracic organ(s) transplantation was a risk factor for CDI following SOT (HR 3.03 [95% CI 1.31-6.98]) for lung and 3.90 (1.58-9.63) for heart and heart/kidney transplant, p = .02. Compared with no-CDI patients, the length of stay (LOS) was prolonged in both allo-HCT (35 days [19-141] vs. 29 [13-164], p < .01) and SOT with CDI (16.5 [4-101] vs. 7 [0-159], p < .01), though not directly attributed to CDI. In allo-HCT, severe acute graft-versus-host disease (aGVHD) occurred more frequently in patients with CDI (33.3% vs. 15.8% without CDI, p = .01) and most aGVHD (87.5%) followed CDI. Non-relapse mortality or overall survival, not attributed to CDI, were also similar in both allo-HCT and SOT.

CONCLUSIONS

Early post-transplant CDI is frequent, associated with fluoroquinolones use in allo-HCT and the transplanted organ in SOT, and is associated with longer LOS in both the groups without difference in survival but with increased aGVHD in allo-HCT.

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.

Effectiveness of Bezlotoxumab for Prevention of Recurrent Clostridioides difficile Infection Among Transplant Recipients

Background

Bezlotoxumab significantly reduces the incidence of recurrent Clostridioides difficile infection (CDI); however, limited data are available in solid organ transplant (SOT) and hematopoietic cell transplant (HCT) recipients.

Methods

We conducted a single-center retrospective analysis comparing recurrent CDI in SOT and HCT recipients receiving standard of care alone (oral vancomycin, fidaxomicin, or metronidazole) or bezlotoxumab plus standard of care. The primary outcome was 90-day incidence of recurrent CDI, and secondary outcomes included 90-day hospital readmission, mortality, and incidence of heart failure exacerbation.

Results

Overall, 94 patients received bezlotoxumab plus standard of care (n = 38) or standard of care alone (n = 56). The mean age was 53 years; patients had a median of 3 prior Clostridioides difficile episodes and 4 risk factors for recurrent infection. Most patients were SOT recipients (76%), with median time to index CDI occurring 2.7 years after transplantation. Ninety-day recurrent CDI occurred in 16% (6/38) in the bezlotoxumab cohort compared to 29% (16/56) in the standard of care cohort (P = .13). Multivariable regression revealed that bezlotoxumab was associated with significantly lower odds of 90-day recurrent CDI (odds ratio, 0.28 [95% confidence interval, .08–.91]). There were no differences in secondary outcomes, and no heart failure exacerbations were observed.

Conclusions

In a cohort of primarily SOT recipients, bezlotoxumab was well tolerated and associated with lower odds of recurrent CDI at 90 days. Larger, prospective trials are needed to confirm these findings among SOT and HCT populations.

A Review of Clostridioides difficile Infection and Antibiotic-Associated Diarrhea

Antibiotic-associated diarrhea and Clostridioides difficile infection (CDI) occur frequently among adults. The pathophysiology of CDI is related to disruption of normal gut flora and risk factors include hospitalization, use of antibiotic therapy, and older age. Clinical manifestations can range from mild disease to toxic megacolon. Diagnosis is challenging and is based on a combination of clinical symptoms and diagnostic tests. Therapy includes cessation of antibiotics, or use of other agents depending on the severity of illness. Many novel agents for the treatment and prevention of CDI show promise and are under investigation.

Infectious Gastroenteritis in Transplant Patients

Infectious gastroenteritis is common after transplantation and can lead to increased morbidity and mortality. A wide range of organisms can lead to gastroenteritis in this patient population. Clostridioides difficile, cytomegalovirus, and norovirus are the most common pathogens. Newer diagnostic methods, especially multiplex polymerase chain reaction, have increased the diagnostic yield of infectious etiologies. In this review, we describe the epidemiology and risk factors for common infectious pathogens leading to gastroenteritis.

Sepsis in Immunocompromised Patients Without Human Immunodeficiency Virus

Sepsis remains among the most common complications from infectious diseases worldwide. The morbidity and mortality rates associated with sepsis range from 20% to 50%. The advances in care for patients with an immunocompromised status have been remarkable over the last 2 decades, but sepsis continues to be a major cause of death in this population Immunocompromised patients who are recipients of a solid organ or hematopoietic stem cell transplant are living longer with a better quality of life. However, some of these patients need lifelong treatment with immunosuppressive medications to maintain their transplant status. A consequence of the need for this permanent immunosuppression is the high risk of opportunistic, community, and hospital-acquired infections, all of which can lead to sepsis. In addition, the detection of serious infections may be more challenging owing to patients' lower ability to mount the clinical symptoms that usually accompany sepsis. This article provides an update on the current knowledge of sepsis in immunocompromised patients without human immunodeficiency virus. It reviews the most pertinent causes of sepsis in this population, and addresses the specific diagnostic and therapeutic challenges in neutropenia and solid organ and hematopoietic stem cell transplantation.

Clostridium difficile disease in solid organ transplant recipients: a recommended treatment paradigm

PURPOSE OF REVIEW

Organ transplant recipients have an increased incidence of Clostridium difficile disease and lower clinical response rates compared with the general population. Transplant specific treatment approaches are not defined. Therefore, a review of therapeutics in the transplant population is needed.

RECENT FINDINGS

A literature review on the current therapies for C. difficile was performed focusing on the evidence in transplant recipients and immunosuppressed populations.

SUMMARY

Transplant patients warrant an aggressive approach to treatment. The authors propose a suggested treatment paradigm for therapy.

Outcomes of C difficile infection in solid-organ transplant recipients: The National Inpatient Sample (NIS) 2015-2016

BACKGROUND

Clostridioides (formerly Clostridium) difficile infection (CDI) is one of the leading causes of morbidity and mortality worldwide. Solid organ transplant (SOT) recipients are at an increased risk for CDI. A recent study showed an overall improvement in mortality amongst hospitalized individuals with CDI, but it is unclear if this benefit extends to SOT recipients.

METHODS

We scrutinized the 2015 and 2016 National Inpatient Sample (NIS), the largest all-payer inpatient database in the United States for CDI data in patients with SOT. SOT was defined as any recipient who had received a heart, lung, liver, intestinal, kidney, pancreas, or combined thoracic and/or abdominal organ transplantation. Baseline characteristics, comorbidities, and concomitant diagnosis of pneumonia or urinary tract infection were adjusted for in our analysis. Primary outcomes included inpatient mortality, hospital length of stay and total hospital charges.

RESULTS

A total of 105 780 hospital discharges of SOT recipients were included. The incidence of CDI was 3554 (3.36%) among SOTs. CDI was associated with a higher inpatient mortality (OR 1.85, 95% CI 1.56-2.20, P < .01), longer length of hospital stay (mean difference 5.07 days, 95% CI 4.43-5.71, P < .01) and higher total hospital charges (mean difference 43 958 US dollars, P < .01).

CONCLUSION

Our study found that CDI is associated with poorer overall outcomes among hospitalized SOT recipients. However, there was a possible improving trend of the outcomes when compare to previous studies.

A multicenter study to define the epidemiology and outcomes of Clostridioides difficile infection in pediatric hematopoietic cell and solid organ transplant recipients

Hematopoietic cell transplant (HCT) and solid organ transplant (SOT) recipients are at increased risk for Clostridioides difficile infection (CDI). We conducted a multicenter retrospective study to describe the incidence of CDI in children transplanted between January 2010 and June 2013. Nested case-control substudies, matched 1:1 by transplant type, institution, patient age, and time of year (quartile) of transplant, identified CDI risk factors. Cohorts included 1496 HCT and 1090 SOT recipients. Among HCT recipients, 355 CDI episodes were diagnosed in 265 recipients (18.2%). Nested case-control study identified prior history of CDI (odds ratio [OR] 2.6, 95% confidence interval [CI] 1.5-4.7), proton pump inhibitors (PPIs; OR 2.1, 95% CI 1.3-3.4), and exposure to third- (OR 2.4, 95% CI 1.4-4.2) or fourth-generation (OR 2.1, 95% CI 1.2-3.7) cephalosporins as risk factors. Notably, fluoroquinolone exposure appeared protective (OR 0.6, 95% CI 0.3-0.9). Ninety-two episodes of CDI were diagnosed among 79 SOT recipients (7.3%), and exposure to PPIs (OR 2.4, 95% CI 1.1-5.4) and third-generation cephalosporin therapy (OR 3.9, 95% CI 1.4-10.5) were identified as risk factors. Strategies to decrease PPI use and changes in the class of prophylactic antibiotics may impact CDI incidence and warrant further study.

Universal molecular Clostridioides difficile screening and overtreatment in solid organ transplant recipients

BACKGROUND

Screening for Clostridioides difficile (CD) colonization can be performed using molecular testing to identify the presence of microbial DNA of the toxin gene. Colonization rates for hospitalized patients are as high as 20% and may be considerably higher in solid organ transplant (SOT) recipients. Treatment for CD should be based on clinical disease and not colonization, yet clinicians may misinterpret a positive CD screen resulting in overtreatment.

OBJECTIVES

The objective of this analysis is to determine how often positive CD screens resulted in inappropriate treatment with oral vancomycin.

METHODS

Clostridioides difficile screens were performed using the Xpert C difficile assay (Cepheid), a nucleic acid amplification testing method utilizing polymerase chain reaction (PCR), on peri-rectal swabs for newly admitted patients. This was a single-center cohort study of adult patients with CD screens hospitalized between July 2015 and November 2018. The primary outcome was the rate of inappropriate oral vancomycin treatment in all patients and in SOT recipients, defined as therapy in the absence of diarrhea.

RESULTS

Of the 47 076 total CD screens reviewed, 1,921 were positive. In the SOT cohort, 58 of 329 screens were positive (4.1% vs 17.9%, P < .01). Of all patients with a positive CD screen, 20.1% (386/1921) were treated with oral vancomycin within 48 hours of swab collection. In the SOT cohort, 39.6% (23/58) with positive CD screens were treated with oral vancomycin within 48 hours. Of the SOT patients who received oral vancomycin, 39% (9/23) did not have true CD infection.

CONCLUSION

Solid organ transplant recipients were more likely to have CD colonization detected by peri-rectal screening than the general inpatient population. SOT and non-SOT patients were treated with oral vancomycin at similar rates in response to the positive screen. Nearly half of the oral vancomycin use in SOT recipients was likely overtreatment, but this finding is limited by the low number of patients in this cohort.

Management and prophylaxis of bacterial and mycobacterial infections among lung transplant recipients

Bacterial and mycobacterial infections are associated with morbidity and mortality in lung transplant recipients. Infectious complications are categorized by timing post-transplant: <1, 1–6, and >6 months. The first month post-transplant is associated with the highest risk of infection. During this period, infections are most commonly healthcare-associated, and include infections related to surgical complications. The lungs and bloodstream are common sites of infections. Common healthcare-associated organisms include methicillin-resistant Staphylococcus aureus (MRSA), Gram-negative bacilli such as Pseudomonas aeruginosa, and Clostridioides difficile. More than 1-month post-transplant, opportunistic infections can occur. Tuberculosis occurs in 0.8–10% of lung transplant recipients which reflects variation in background prevalence. The majority of post-transplant tuberculosis stems from reactivation of untreated or undiagnosed latent tuberculosis. Most post-transplant tuberculosis occurs in the lungs and develops within a year of transplant. Non-tuberculous mycobacteria commonly colonize the lungs of lung transplant candidates and are often hard to eradicate even with prolonged courses of antimycobacterial agents. Drug interactions between antimycobacterial agents and calcineurin and mTOR inhibitors also complicates treatment post-transplant. Given that infection adversely impacts outcomes after lung transplant, and that anti-infective therapy is often less effective after transplant, infection prevention is key to long-term success. A comprehensive approach that includes pre-transplant evaluation, perioperative prophylaxis, long-term antimicrobial prophylaxis, immunization, and safer living at home and in the community, should be employed to minimize the risk of infection.

Management of Antimicrobial Agents in Abdominal Organ Transplant Patients in Intensive Care Unit

PURPOSE OF REVIEW

Early diagnosis of infections and immediate initiation of appropriate antimicrobials are crucial in the management of patients before and after organ transplantation. We reviewed the most recent literature and guidelines in this field and organized the current recommendations for healthcare professionals caring for critically ill organ transplant recipients.

RECENT FINDINGS

The incidence of multidrug-resistant organisms is increasing. Multidrug-resistant Gram-negative bacteria comprise about 14% of organisms. Vancomycin-resistant enterococci bloodstream infections are also on the rise, as 20.5% of nosocomial enterococci are now vancomycin-resistant, changing empiric antibiotic selection. Fluconazole-resistant Candida species comprise up to 46% of cases of candidemia in hospitalized patients. Consequently, new guidelines recommend primary use of echinocandins in patients with candidemia who have moderate-to-severe disease. Finally, the incidence of emergence of ganciclovir-resistant cytomegalovirus infection in patients is 5-12%, requiring early recognition and change to alternative regimens in the case of poor response to therapy.

SUMMARY

Bloodstream infections are a major cause of mortality and morbidity in solid organ transplantation. Mortality as high as 24% and 50% have been reported with sepsis and septic shock respectively. As such, bloodstream infections should be diagnosed rapidly and intravenous antibiotics should be started immediately. Appropriate resuscitation should be initiated and the number and/or dose of immunosuppressive drugs should be reduced. Proper source control must also be achieved with radiologic drainage or surgical intervention as appropriate. Initial antibiotic treatment of these patients should cover both Gram-positive organisms, especially in the presence of intravascular catheters, and Gram-negative bacteria. Echinocandins like caspofungin should also be considered especially in critically ill patients, particularly if a patient has been on total parenteral nutrition or broad-spectrum antibiotics.