Screening of donor and recipient in solid organ transplantation

The impact of donor hepatitis B virus infection on transplant outcomes in deceased donor kidney transplantation recipients

BACKGROUND

The use of hepatitis B virus (HBV)-positive donor kidneys to expand the donor pool has been implemented, but limited evidence exists regarding their impact on transplant outcomes. This study aimed to investigate the effects of donor HBV infection on transplant outcomes.

METHODS

Donor and recipient data between 2015 and 2021 were collected. A total of 743 kidney transplant cases were screened, including 94 donor hepatitis B surface antigen (HBsAg)+/recipient HBsAg- (D+R-) and 649 donor HBsAg-/recipient HBsAg- (D-R-) cases. The analysis endpoints included recipient HBV infection, delayed graft function (DGF), peak estimated glomerular filtration rate (eGFR) within 12 months, recipient survival, and death-censored graft survival (DCGS).

RESULTS

The D+R- group had a significantly higher risk of HBV infection compared to the D-R- group (6/72 vs. 3/231; relative risk, 6.4; p = 0.007). The risk of HBV transmission decreased significantly with increasing hepatitis B surface antibody (HBsAb) titer (p for trend = 0.003). Furthermore, the D+R- group did not exhibit an increased risk of DGF compared to the D-R- group (odds ratio, 0.70; p = 0.51) in the multivariable mixed model. Both groups had similar peak eGFR within 12 months (β = 1.01, p = 0.71), and this had no impact on patient survival (hazard ratio [HR], 0.36; p = 0.10) and DCGS (HR, 0.79, p = 0.59) in the shared-frailty Cox model.

CONCLUSION

The use of HBsAg-positive donor kidneys appears relatively safe for HBV-immunized recipients in the short term. D+R- does not negatively affect graft function recovery and provides comparable posttransplant outcomes. Maintaining an HBsAb titer over 100 mIU/mL before transplantation is critical to reduce the risk of HBV transmission.

Dengue in patients with kidney transplant: a systematic review

Introduction

The incidence of dengue and its complications increases globally, mainly in areas where it is endemic; however, little literature evaluates outcomes in kidney transplant recipients (KTR). The present analysis aimed to determine the incidence, signs and symptoms, and allograft dysfunction in dengue-infected KTR.

Methods

Systematic review of the literature following PRISMA 2020 indications with studies included until November 24, 2023.

Results

Of 309 articles found, seven full-text studies were identified for analysis. 4337 KTRs with 214 dengue cases were evaluated. The incidence of dengue was 4.93%, varying between geographic regions. The average age was 41.50 years, and 61.21% were men. A mortality of 7.01% was reported. The symptoms were fever 83.18%, arthralgia 19.46%, myalgia 43.24% and headache 34.18%. The proportions of febrile dengue, with warning signs and severe dengue, were 63.55%, 23.83% and 11.68%, respectively. Transplant dysfunction and loss occurred in 63.08% and 4.67%, respectively.

Conclusions

Although the global distribution of dengue in KTR is unknown, there is a variable incidence between geographical areas and study times in which the KTR are evaluated. There is a high incidence of febrile symptomatology and transplant dysfunction consistent with global cohorts for non-KTR and KTR patients, respectively. Dysfunction is a prevalent event in KTRs with dengue infection, so correct screening should be done for donors and transplant candidates.

Understanding immunological insights of liver transplantation: a practice for attaining operational tolerance

Liver transplantation has been at the forefront of medical research, with efforts concentrated on understanding the intricate cellular and molecular dynamics involved this complex procedure. This body of work has chronicled critical clinical advancements, identified challenges, and highlighted progressive improvements in surgical practices. These concerted efforts have significantly contributed to the evolution and enhancement of liver transplantation, elevating it to its current level of sophistication. A successful liver transplant now demands an integrated, multidisciplinary approach that includes not only expanding the donor pool from deceased to living donors but also embracing advances in surgical methods, efficiently managing post-transplant complications, and, importantly, achieving operational tolerance. The latter, operational tolerance, is a state wherein the recipient's immune system is coaxed into accepting the transplanted organ without the long-term use of immunosuppressive drugs, thereby minimizing potential side effects, and improving quality of life. Understanding the critical immune mechanisms that aim to prevent graft rejection is essential from an immunological perspective. This review aims to highlight the crucial areas of host versus graft immune responses, making a clear distinction between organs received from living and deceased donors. It examines how these immune responses, both innate and adaptive, are initiated and proposes the exploration of molecular docking sites as a strategy to curb unwanted immune reactions. Additionally, this review explores the promising potential of biomarkers in predicting graft rejection, and emphasizes the importance of achieving tolerance and the continuous quest for innovative strategies to enhance the success and longevity of liver transplants.

Minimizing risk while maximizing opportunity: The infectious disease organ offer process survey

BACKGROUND

The purpose of this study was to understand how transplant infectious disease (TID) physicians assess a potential donor with known or suspected infection and describe posttransplant management.

METHODS

We designed a survey of 10 organ offer scenarios and asked questions pertaining to organ acceptability for transplantation and management posttransplant. The survey was distributed to TID clinicians via transplant society listservs and email. Responses were recorded in REDCap, and descriptive statistics were employed.

RESULTS

One hundred thirteen infectious disease physicians responded to the survey, of whom 85 completed all cases. Respondents were generally in agreement regarding organ acceptability, although some divergence was seen when evaluating lungs from donors with influenza, tuberculosis, or multidrug-resistant Acinetobacter infection. Posttransplant management showed more variation. Areas of optimization were identified: (1) Further understanding of where risk-mitigation strategies within the donor offer process may improve donor acceptability and therefore organ utilization; (2) importance of recipient considerations in assessing degree of infectious risk; and (3) gaps in evidenced-based data regarding optimal posttransplant management of recipients.

CONCLUSION

Evaluation of donor offers by TID clinicians is a complex process. Although the survey does not itself serve to make recommendations regarding best practices, it highlights areas where generation of data to inform acceptance and management practices may allow for improved organ utilization and recipient management.

A Digital Approach to Improve Infection Screening Among Solid Organ Transplant Candidates

BACKGROUND

Pretransplant infection screening (IS) of potential organ recipients is essential to optimal outcome of solid organ transplantation (SOT).

METHODS

A pre-post study was performed during 2020-2023 to investigate the impact of the STREAM (Solid organ TRansplant stEwArdship and Multidisciplinary approach) intervention to improve IS in SOT. The intervention, performed in 2022, included the implementation of IS through educational meetings, local guidelines, and the availability of a digital screening tool. The objective of the study was the assessment of IS completion, including a list of 17 laboratory tests and the investigation of vaccination status. The reduction of unnecessary tests was also analyzed. The test of proportions and a multilevel multivariate Poisson regression model were used to compare IS completion before and after STREAM. infectious diseases (ID) consultation and urgent evaluation were investigated as predictors of IS completion.

RESULTS

A total of 171 patients were enrolled, including liver (44%), heart (32%), and kidney (24%) transplant candidates. Mean age was 56 ± 11 years, and most patients (77%) were males. Ninety-five (56%) patients were included before the intervention and 76 (44%) after STREAM. IS completion increased after STREAM (IRR 1.41, p < 0.001) with significant improvement recorded for seven (39%) IS items. Unnecessary tests decreased by 43% after the intervention. ID consultation (IRR 1.13, p = 0.02) and urgent evaluation (p = 0.68, p < 0.001) were predictors of IS improvement.

CONCLUSIONS

STREAM was successful in improving IS completion. Further research is needed to investigate the impact of this intervention on posttransplant infections.

Frequency of and reasons behind non-listing in adult patients referred for liver transplantation: Results from a retrospective study

BACKGROUND

Few studies have evaluated the frequency of and the reasons behind the refusal of listing liver transplantation candidates.

AIM

To assess the ineligibility rate for liver transplantation and its motivations.

METHODS

A single-center retrospective study was conducted on adult patients which entailed a formal multidisciplinary assessment for liver transplantation eligibility. The predictors for listing were evaluated using multivariable logistic regression.

RESULTS

In our center, 314 patients underwent multidisciplinary work-up before liver transplantation enlisting over a three-year period. The most frequent reasons for transplant evaluation were decompensated cirrhosis (51.6%) and hepatocellular carcinoma (35.7%). The non-listing rate was 53.8% and the transplant rate was 34.4% for the whole cohort. Two hundred and five motivations for ineligibility were collected. The most common contraindications were psychological (9.3%), cardiovascular (6.8%), and surgical (5.9%). Inappropriate or premature referral accounted for 76 (37.1%) cases. On multivariable analysis, a referral from another hospital (OR: 2.113; 95%CI: 1.259-3.548) served as an independent predictor of non-listing.

CONCLUSION

A non-listing decision occurred in half of our cohort and was based on an inappropriate or premature referral in one case out of three. The referral from another hospital was taken as a strong predictor of non-listing.

Diagnosing and Managing Urinary Tract Infections in Kidney Transplant Recipients

In the article, the authors review antibiotic treatment options for both acute uncomplicated UTI and complicated UTI. In addition, they review alternative regimens which are needed in the setting of drug-resistant pathogens including vancomycin-resistant Enterococcus, -extended-spectrum beta-lactamase-producing Enterobacterales (ESBL-E), carbapenem-resistant Enterobacterales, and carbapenem-resistant Pseudomonas, which are encountered with more frequency.

Infections in lung transplanted patients: A review

Lung transplantation can improve the survival of patients with severe chronic pulmonary disorders. However, the short- and long-term risk of infections can increase morbidity and mortality rates. A non-systematic review was performed to provide the most updated information on pathogen, host, and environment-related factors associated with the occurrence of bacterial, fungal, and viral infections as well as the most appropriate therapeutic options. Bacterial infections account for about 50% of all infectious diseases in lung transplanted patients, while viruses represent the second cause of infection accounting for one third of all infections. Almost 10% of patients develop invasive fungal infections during the first year after lung transplant. Pre-transplantation comorbidities, disruption of physical barriers during the surgery, and exposure to nosocomial pathogens during the hospital stay are directly associated with the occurrence of life-threatening infections. Empiric antimicrobial treatment after the assessment of individual risk factors, local epidemiology of drug-resistant pathogens and possible drug-drug interactions can improve the clinical outcomes.

Epidemiology and Management of Infections in Liver Transplant Recipients

Background: Improvements in liver transplant (LT) outcomes are attributed to advances in surgical techniques, use of potent immunosuppressants, and rigorous pre-LT testing. Despite these improvements, post-LT infections remain the most common complication in this population. Bacteria constitute the most common infectious agents, while fungal and viral infections are also frequently encountered. Multi-drug-resistant bacterial infections develop because of polymicrobial overuse and prolonged hospital stays. Immediate post-LT infections are commonly caused by viruses. Conclusions: Appropriate vaccination, screening of both donor and recipients before LT and antiviral prophylaxis in high-risk individuals are recommended. Antimicrobial drug resistance is common in high-risk LT and associated with poor outcomes; epidemiology and management of these cases is discussed. Additionally, we also discuss the effect of coronavirus disease 2019 (COVID-19) infection and monkeypox in the LT population.

Donor blood cultures and outcomes after lung transplantation: a single-center report

BACKGROUND

Transplanting lungs from donors with positive blood cultures has not been shown to adversely affect survival. There is limited evidence for potential effects on other outcomes, such as hospital course, graft function, and transmission of infection.

METHODS

This retrospective cohort study included adult patients who underwent lung-only transplantation for the first time between March 2010 and December 2022. Outcomes of patients whose donors had positive blood cultures within 72 h of transplant were compared to patients whose donors had negative blood cultures.

RESULTS

Twenty-five (10.8%) of 232 donors had positive blood cultures, including a single, unexpected case with candidemia. The most commonly isolated bacteria were Enterobacter cloacae (n = 5), Klebsiella pneumoniae (n = 5), Acinetobacter baumannii (n = 3), Pseudomonas aeruginosa (n = 3), and Staphylococcus aureus (n = 3). Eleven donors had identical bacteria in their respiratory cultures. All patients who were transplanted from donors with positive blood cultures survived beyond 90 days. Positive donor blood cultures were not associated with longer hospital stay, in-hospital complications, acute cellular rejection, or the achievement of 80% predicted forced expiratory volume in the first second. Probable transmission of donor bacteremia occurred in only two cases (both with S. aureus). These two donors had positive respiratory cultures with the same organism.

CONCLUSION

The study did not find an increased risk of adverse events when transplanting lungs from donors with positive blood cultures. Allograft cultures may be more predictive of the risk of transmitting infections.

Pre-Transplant Seroprevalence, Associated Factors, and Post-Transplant Incidence of Toxoplasma gondii Infection Among Heart Transplant Recipients in Japan

BACKGROUND

Among solid organ transplant (SOT) recipients, heart transplant (HT) recipients are at a higher risk of Toxoplasma gondii infection. As Toxoplasma seroprevalence varies by geographic location, updated local epidemiology is essential to guide preventive and therapeutic strategies. However, the Toxoplasma seroprevalence and incidence of post-transplant toxoplasmosis among SOT recipients in Japan are unknown.

METHODS

We performed a single-center retrospective observational study at an HT center in Tokyo, Japan. All HT recipients aged ≥18 years between 2006 and April 2019 were included. We reviewed patient charts and conducted a questionnaire survey to investigate the risk factors for infection.

RESULTS

Among 105 recipients included in the study, 11 (10.5%) were seropositive before transplant. Ninety-five recipients (90.5%), including all pre-transplant seropositive recipients, answered the questionnaire. The recipients who had lived in Okinawa (odds ratio [OR] 7.5 [95% CI 1.42-39.61]; P = .032) and who reported raw-meat eating habits (OR 4.64 [95% CI 1.04-23.3]; P = .021) were more likely to be seropositive. None of the patients developed symptoms of toxoplasmosis. The post-transplant incidence of other major adverse outcomes was not significantly different according to the pre-transplant serostatus.

CONCLUSIONS

About 10% of HT recipients at an HT center in Tokyo were seropositive for Toxoplasma pre-transplant, and none developed symptomatic toxoplasmosis post-transplant on trimethoprim-sulfamethoxazole. The history of raw meat consumption was associated with seropositivity; therefore, avoiding it might be recommended for HT recipient candidates.

Optimal Perioperative Antimicrobial Management Strategies of Kidney Transplant Recipients Guided by Metagenomic Next-Generation Sequencing of Deceased Donors' Microbiology Samples

Background

There is no consensus on the optimal use of perioperative antibiotics prophylaxis after kidney transplantation, but there is a common trend to limit the duration of antibiotic use worldwide. Metagenomic next-generation sequencing (mNGS) has emerged as a novel technology for pathogen detection in clinical practice due to its noninvasive, rapid, precise and high susceptibility to detect infectious pathogens. However, data are lacking on whether mNGS analyses could be used to detect pathogens and guide anti-infection regimens in kidney transplant donors and recipients.

Methods

We conducted a retrospective study to review all clinic data of mNGS and traditional laboratory methods (TMs) for pathogen detection in kidney transplant recipients and their corresponding deceased donors from August 1, 2021 to October 30, 2022 in our center.

Results

A total of 57 donors and 112 of their corresponding recipients were included. The antimicrobial strategy mainly depended on mNGS results combined with traditional pathogen culture and clinical conditions. The percentages of positive pathogen detected by mNGS in blood, urine, bronchoalveolar lavage fluid (BALF) and preservation fluids (PFs) were 50.9% (29/57), 35.1% (20/57), 84.2% (48/57) and 54.4% (31/57) respectively, and were 24.6% (14/57), 15.8% (9/57), 57.9% (33/57) and 14.1% (8/57) respectively when using TMs. mNGS could detected all of pathogens which were detected by TMs. However, samples with negative TMs testing can be additionally detected as positive by mNGS (15/43 in blood, 11/48 in urine, 15/24 in BALF and 23/49 in PFs). Drug resistance genes were detected in 9 donors by mNGS,which were consistent with 6 donors by TMs. There was only one case of donor-derived infection in this study.

Conclusion

This study showed that it is effective to combine mNGS with traditional pathogen detection methods and clinical features to develop optimal perioperative antimicrobial management strategies for deceased donor kidney transplantation.

Prevention, diagnosis, and management of donor derived infections in pediatric kidney transplant recipients

Donor derived infections (DDIs) in pediatric kidney transplant recipients remain challenging to diagnose and can result in serious morbidity and mortality. This review summarizes the current guidelines and recommendations for prevention, diagnosis, and treatment of unexpected DDIs in pediatric kidney transplant recipients. We provide a contemporary overview of DDI terminology, surveillance, epidemiology, and recommended approaches for assessing these rare events with an emphasis on the pediatric recipient. To address prevention and risk mitigation, important aspects of donor and pediatric candidate evaluations are reviewed, including current Organ Procurement and Transplantation Network (OPTN) and American Society of Transplantation (AST) recommendations. Common unexpected DDI encountered by pediatric transplant teams including multi-drug resistant organisms, tuberculosis, syphilis, West Nile Virus, toxoplasmosis, Chagas disease, strongyloidiasis, candidiasis, histoplasmosis, coccidioidomycosis, and emerging infections such as COVID-19 are discussed in detail. Finally, we consider the general challenges with management of DDIs and share our experience with a novel application of next generation sequencing (NGS) of microbial cell-free DNA that will likely define a future direction in this field.

Bacterial and Viral Infections in Liver Transplantation: New Insights from Clinical and Surgical Perspectives

End-stage liver disease patients undergoing liver transplantation are prone to develop numerous infectious complications because of immunosuppression, surgical interventions, and malnutrition. Infections in transplant recipients account for the main cause of mortality and morbidity with rates of up to 80%. The challenges faced in the early post-transplant period tend to be linked to transplant procedures and nosocomial infections commonly in bloodstream, surgical, and intra-abdominal sites. Viral infections represent an additional complication of immunosuppression; they can be donor-derived, reactivated from a latent virus, nosocomial or community-acquired. Bacterial and viral infections in solid organ transplantation are managed by prophylaxis, multi-drug resistant screening, risk assessment, vaccination, infection control and antimicrobial stewardship. The aim of this review was to discuss the epidemiology of bacterial and viral infections in liver transplants, infection control issues, as well as surgical frontiers of ex situ liver perfusion.

Chronic Infections in Mammals Due to Microsporidia

Microsporidia are pathogenic organism related to fungi. They cause infections in a wide variety of mammals as well as in avian, amphibian, and reptilian hosts. Many microsporidia species play an important role in the development of serious diseases that have significant implications in human and veterinary medicine. While microsporidia were originally considered to be opportunistic pathogens in humans, it is now understood that infections also occur in immune competent humans. Encephalitozoon cuniculi, Encephalitozoon intestinalis, and Enterocytozoon bieneusi are primarily mammalian pathogens. However, many other species of microsporidia that have some other primary host that is not a mammal have been reported to cause sporadic mammalian infections. Experimental models and observations in natural infections have demonstrated that microsporidia can cause a latent infection in mammalian hosts. This chapter reviews the published studies on mammalian microsporidiosis and the data on chronic infections due to these enigmatic pathogens.

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.

Artificial Intelligence May Predict Early Sepsis After Liver Transplantation

Background: Sepsis, post-liver transplantation, is a frequent challenge that impacts patient outcomes. We aimed to develop an artificial intelligence method to predict the onset of post-operative sepsis earlier. Methods: This pilot study aimed to identify "physiomarkers" in continuous minute-by-minute physiologic data streams, such as heart rate, respiratory rate, oxygen saturation (SpO2), and blood pressure, to predict the onset of sepsis. The model was derived from a cohort of 5,748 transplant and non-transplant patients across intensive care units (ICUs) over 36 months, with 92 post-liver transplant patients who developed sepsis. Results: Using an alert timestamp generated with the Third International Consensus Definition of Sepsis (Sepsis-3) definition as a reference point, we studied up to 24 h of continuous physiologic data prior to the event, totaling to 8.35 million data points. One hundred fifty-five features were generated using signal processing and statistical methods. Feature selection identified 52 highly ranked features, many of which included blood pressures. An eXtreme Gradient Boost (XGB) classifier was then trained on the ranked features by 5-fold cross validation on all patients (n = 5,748). We identified that the average sensitivity, specificity, positive predictive value (PPV), and area under the receiver-operator curve (AUC) of the model after 100 iterations was 0.94 ± 0.02, 0.9 ± 0.02, 0.89 ± 0.01, respectively, and 0.97 ± 0.01 for predicting sepsis 12 h before meeting criteria. Conclusion: The data suggest that machine learning/deep learning can be applied to continuous streaming data in the transplant ICU to monitor patients and possibly predict sepsis.

Reactivation of latent infections in solid organ transplant recipients from sub-Saharan Africa: What should be remembered?

International migration from Sub-Saharan African countries to the European Union and the United States has significantly increased over the past decades. Although the vast majority of these immigrants are young and healthy people, a minority can be affected by chronic conditions eventually leading to solid organ transplantation (SOT). Importantly, these candidates can bear geographically restricted fungal and parasitic latent infections that can reactivate after the procedure. An appropriate evaluation before transplantation followed by treatment, whenever necessary, is essential to minimize such risk, as covered in the present review. In short, infection due to helminths (Schistosoma spp. and Strongyloides stercoralis) and intestinal protozoa (Entamoeba histolytica, Giardia lamblia or Cyclospora cayetanensis) can be diagnosed by multiple direct stool examination, serological assays and stool antigen testing. Leishmaniasis can be assessed by means of serology, followed by nucleic acid amplification testing (NAAT) if the former test is positive. Submicroscopic malaria should be ruled out by NAAT. Screening for Histoplasma spp. or Cryptococcus spp. is not routinely indicated. Consultation with an Infectious Diseases specialist is recommended in order to adjust preemptive treatment among Sub-Saharan African SOT candidates and recipients.

How I prevent infections in patients receiving CD19-targeted chimeric antigen receptor T cells for B-cell malignancies

Adoptive immunotherapy using B-cell-targeted chimeric antigen receptor (CAR)-modified T cells to treat hematologic malignancies is transforming cancer care for patients with refractory or relapsed diseases. Recent and anticipated regulatory approval for products targeting acute lymphoblastic leukemia, lymphomas, and multiple myeloma have led to global implementation of these novel treatments. The rapidity of commercial utilization of CAR-T-cell therapy has created a largely unexplored gap in patient supportive-care approaches. Such approaches are critical in these complex patients given their high net state of immunosuppression prior to CAR-T-cell infusion coupled with unique acute and persistent insults to their immune function after CAR-T-cell infusion. In this "How I Treat" article, we focus on key questions that arise during 3 phases of management for patients receiving CD19-targeted CAR-T cells: pre CAR-T-cell infusion, immediate post CAR-T-cell infusion, and long-term follow-up. A longitudinal patient case is presented for each phase to highlight fundamental issues including infectious diseases screening, antimicrobial prophylaxis, immunoglobulin supplementation, risk factors for infection, and vaccination. We hope this discussion will provide a framework for institutions and health care providers to formulate their own approach to preventing infections in light of the paucity of data specific to this treatment modality.

Update in Viral Infections in the Intensive Care Unit

The advent of highly sensitive molecular diagnostic techniques has improved our ability to detect viral pathogens leading to severe and often fatal infections that require admission to the Intensive Care Unit (ICU). Viral infections in the ICU have pleomorphic clinical presentations including pneumonia, acute respiratory distress syndrome, respiratory failure, central or peripheral nervous system manifestations, and viral-induced shock. Besides de novo infections, certain viruses fall into latency and can be reactivated in both immunosuppressed and immunocompetent critically ill patients. Depending on the viral strain, transmission occurs either directly through contact with infectious materials and large droplets, or indirectly through suspended air particles (airborne transmission of droplet nuclei). Many viruses can efficiently spread within hospital environment leading to in-hospital outbreaks, sometimes with high rates of mortality and morbidity, thus infection control measures are of paramount importance. Despite the advances in detecting viral pathogens, limited progress has been made in antiviral treatments, contributing to unexpectedly high rates of unfavorable outcomes. Herein, we review the most updated data on epidemiology, common clinical features, diagnosis, pathogenesis, treatment and prevention of severe community- and hospital-acquired viral infections in the ICU settings.

Measles outbreak risk assessment for transplant candidates and recipients

Solid organ transplant (SOT) candidates and recipients are at risk of significant morbidity and mortality from infection, including those circulating in the community from unexpected outbreaks. In late 2018-summer of 2019, a measles outbreak occurred in the New York City area, with a total of 649 cases reported. We developed a systematic 3-part approach to address measles risk in our adult SOT program through: (a) identification of nonimmune adults living in outbreak ZIP codes, (b) education focused on risk reduction for patients from outbreak ZIP codes, and (c) risk reduction for nonimmune patients. All waitlisted or previously transplanted patients residing in outbreak areas received a measles patient education handout. The electronic medical record of patients born in or after 1957 was reviewed for serologic evidence of measles immunity. Measles immunity testing was performed in patients without documentation of immunity. Patients who tested nonimmune were offered MMR vaccination or intravenous immunoglobulin depending on their transplant phase and risk profile. Thus, we demonstrate successful implementation of a systematic risk assessment during a large measles outbreak to identify and protect at-risk SOT patients. As vaccine hesitancy persists, our strategies may be increasingly relevant to transplant centers and those caring for immunocompromised patients.

Donor-derived fatal hyperinfection strongyloidiasis in renal transplant recipient

Strongyloides stercoralis is a nematode, endemic in tropical and subtropical areas. Strongyloidiasis has been reported in recipients of hematopoietic stem cells, kidney, liver, heart, intestine, and pancreas, eventually presenting as disseminated strongyloidiasis and hyperinfection syndrome (SHS) which is associated with high mortality. We report one case of a recent renal transplant recipient, who presented with gastrointestinal and respiratory symptoms, evolving into shock. The identification of Strongyloides stercoralis in the bronchoalveolar lavage (BAL) lead us to the diagnosis of SHS. Treatment with subcutaneous ivermectin was started, however the patient did not survive. Retrospective serum donor analysis allowed us to identify the donor as the source of infection.

Selection criteria of solid organ donors in relation to infectious diseases: A Spanish consensus

The immunosuppressive treatment that recipients receive from a solid organ transplantation hinders the defensive response to infection. Its transmission from the donor can cause dysfunction or loss of the graft and even death of the recipient if proper preventive measures are not established. This potential risk should be thoroughly evaluated to minimise the risk of infection transmission from donor to recipient, especially with organ transplantation from donors with infections, without increasing graft dysfunction and morbidity and mortality in the recipient. This document aims to review current knowledge about infection screening in potential donors and offer clinical and microbiological recommendations about the use of organs from donors with infection based on available scientific evidence.

Antibiotic therapy in case of positive cultures of kidney transplant preservation fluid: a nationwide survey of prescribing practices

Our survey aimed to describe current prescribing practices for perioperative antibiotic prophylaxis in French kidney transplant centers. We conducted a nationwide cross-sectional clinical vignette-based survey that we sent via email to hospital practitioners involved in perioperative management of kidney transplant patients (KTR). Nearly half of practitioners contacted (182/427, 42.6%) were respondents. A total of 167 getting enough kidney transplant activity were eligible for the survey. The response rate was 50.7% (68/134) among interns and 33.8% (99/293) among seniors. Positive perfusion fluids (PF) cultures for methicillin-susceptible Staphylococcus aureus were associated with antibiotic prescribing in 35% of cases, with no difference in prescribing in patients with diabetes, obesity, or delayed graft function. Antibiotic prescribing was most frequent with Pseudomonas aeruginosa (67%) and Klebsiella pneumoniae strains producing extended spectrum β-lactamases (57%). About 77%, 16%, and 13% of respondents, respectively, reported the existence of local practice guidelines for surgical antibiotic prophylaxis, a standardized approach for antibiotic prescribing in case of positive kidney transplant PF cultures, and local practice guidelines for systematical antibiotic prophylaxis in the early post-transplant period. In France, antibiotic prophylaxis practices in the perioperative kidney transplant period are very heterogeneous. To prevent unnecessary prescribing and bacterial resistance, evidence-based practice guidelines should be developed.

Donor-derived bacterial infections in lung transplant recipients in the era of multidrug resistance

OBJECTIVES

Our aim was to analyze the prevalence of multidrug-resistant bacterial infections in lung transplant donors and to evaluate its influence on donor-derived bacterial infections.

METHODS

We conducted a retrospective study of adult patients who underwent lung transplantation (2013-2016) at our hospital. Donor-derived bacterial infection was defined as the isolation of the same bacteria with identical antibiotic susceptibility patterns in the recipient and the perioperative cultures from the donor during the first month posttransplantation. We utilized a preventive antibiotic strategy adapted to the bacteria identified in donor cultures using systemic and nebulized antibiotics.

RESULTS

252 lung transplant recipients and 243 donors were included. In 138/243 (56.8%) donors, one bacterial species was isolated from at least one sample; graft colonization (118/243; 48.6%), blood cultures (5/243; 2.1%) and the contamination of preservation fluids (56/243; 23%). Multidrug-resistant bacteria were isolated from 12/243 (4.9%) donors; four Enterobacterales, four Stenotrophomonas maltophilia, three Pseudomonas aeruginosa and one methicillin-resistant Staphylococcus aureus. There was no transmission of these multidrug-resistant bacteria. Donor-derived infections, primarily tracheobronchitis due to non-MDR bacteria, were diagnosed in 7/253 (2.9%) recipients, with good clinical outcomes.

CONCLUSIONS

The lungs of donors colonized with multidrug-resistant bacteria may be safely used when recipients receive prompt tailored antibiotic treatment.

Microbiological epidemiology of preservation fluids in transplanted kidney: a nationwide retrospective observational study

OBJECTIVES

Kidney transplant recipients are at high-risk for donor-derived infections in the early post-transplant period. Transplant preservation fluid (PF) samples are collected for microbiological analysis. In case of positive PF cultures, the risk for the recipient is unknown and there is no consensus for prescribing prophylactic antibiotics. This nationwide observational study aimed to determine the epidemiology of bacterial and fungal agents in kidney transplant PF cultures and identify risk factors associated with positive PF cultures.

METHODS

We performed a retrospective observational study on the following data collected from a national database between October 2015 and December 2016: characteristics of donor, recipient, transplantation, infection in donor and PF microbiological data.

RESULTS

Of 4487 kidney transplant procedures, including 725 (16.2%, 725/4487) from living donors, 20.5% had positive PF cultures (living donors: 1.8%, 13/725; deceased donors: 24.1%, 907/3762). Polymicrobial contamination was found in 59.9% (485/810) of positive PF cultures. Coagulase-negative staphylococci (65.8%, 533/810) and Enterobacteriaceae (28.0%, 227/810) were the most common microorganisms. Factors associated with an increased risk of positive PF cultures in multivariable analysis were (for deceased-donor kidney transplants): intestinal perforation during procurement (OR 4.4, 95% CI 2.1-9.1), multiorgan procurement (OR 1.4, 95% CI 1.1-1.7) and en bloc transplantation (OR 2.5, 95% CI 1.3-4.9). Use of perfusion pump and donor antibiotic therapy were associated with a lower risk of positive PF cultures (OR 0.4, 95% CI 0.3-0.5 and OR 0.6, 95% CI 0.5-0.7, respectively).

CONCLUSION

In conclusion, 24% of deceased-donor PF cultures were positive, and PF contamination during procurement seemed to be the major cause.

A scoping review of transmission of dengue virus from donors to recipients after solid organ transplantation

Dengue virus can infect humans through vectorial and non-vectorial transmission. Classically, non-vectorial transmission has been related to vertical transmission and health care-associated infections, but recently transmission to solid organ and bone marrow recipients has been reported. We performed a scoping review of the available literature searching for evidence on screening for dengue in potential organ donors and the use of these infected organs. From 372 unique records identified, 17 were eligible to be included in our scoping study. After applying inclusion and exclusion criteria, three studies were included. These studies described a total of six patients from India (two case reports; n=2) and Colombia (one case series; n=4). Three patients received a liver, two received a kidney and one had a heart transplant. The onset of symptoms occurred in the first week after transplant in all cases and all experienced fever as the primary symptom. All patients presented thrombocytopenia with a platelet count <50 000. None of the patients developed graft rejection. However, four patients presented graft complications. No recipient deaths occurred. There is not a strong recommendation for dengue screening of donors in transplantation guidelines, but in endemic areas, physicians should be aware of this type of transmission before transplantation.

Romiplostim as a transfusion saving strategy in 20 patients after heart or lung transplantation: a single centre before-after pilot study

BACKGROUND

Thrombocytopenia is a common disorder after heart or lung transplantation. Platelet transfusion is often required to maintain haemostasis but represents a specific cause of morbidity and mortality in this setting including alloimmunisation and graft rejection.

STUDY DESIGN AND METHODS

As part of a health-care quality improvement project, in a single-centre before-after pilot study, the relevance of a platelet transfusion saving strategy based on romiplostim administration after transplantation was assessed in patients with platelet count <100 × 10⁹/L. Transfusions on days 28 and 90 were compared using propensity matched score for adjustment of demographic characteristics at baseline. The primary outcome was platelet transfusion until day 28 after transplantation.

RESULTS

Ninety-three patients were analysed (73 before vs. 20 after). The median [interquartile range] number of platelet concentrate was 1 [0;4.0] before versus 0.5 [0;2.0] in the after period, mean difference 0.5 confidence interval 95% [-0.7 to 1.7], p = 0.39. On day 28, median [interquartile range] red blood cell transfusion was significantly higher in the before versus the after period, 7 [2.0;13.5] versus 6 [1.5;8.5], mean difference 3.2 CI 95% [0.4-6.0], p = 0.02. At 6 months, the rate of patients with de novo anti-human leukocyte antigen alloimmunisation was 45% before versus 53% in the after period (p = 0.56). Deep venous thrombosis was detected in nine patients (12%) before versus seven patients (35%) in the after period (p = 0.04).

CONCLUSION

Romiplostim did not significantly reduce platelet transfusion after heart or lung transplantation. Its relevance and safety in a global transfusion strategy remains to be studied in this setting in a large randomised study.

Carbapenem-Resistant Enterobacteriaceae in Solid Organ Transplantation: Management Principles

PURPOSE OF REVIEW

Carbapenem-resistant Enterobacteriaceae (CRE) have emerged as a worldwide problem. Given their degree of immunosuppression and the level of contact with the healthcare system, solid organ transplant (SOT) recipients are at a disproportionately higher risk of acquisition, colonization, and infection with CRE, and outcomes from infection tend to be worse compared to non-transplant patients. Therapeutic options are limited for CRE infections although several newer agents have recently been approved for use. How well these agents perform in the setting of immunosuppression and SOT is unclear. We sought to review the epidemiology of CRE in SOT and the management principles.

RECENT FINDINGS

CRE infections are becoming an increasing problem in SOT, and donor-derived infections present a challenge in the peri-transplant period. Newer treatments for CRE are emerging that are less toxic and potentially more effective than prior CRE-active agents, but supportive clinical data are limited. Newer beta-lactamase inhibitors have good activity against KPC carbapenemases, but they lack activity against metallo-beta-lactamases (e.g., NDM). Promising data is emerging with newer agents that have activity against most carbapenemases, but, again, clinical data is needed. Combination therapy in addition to optimal pharmacokinetic and pharmacodynamics may go some way to improve outcomes against these difficult-to-treat organisms. Other novel therapies that prevent the emergence of resistance (oral beta-lactamase inhibitors) and eradication of resistant Gram-negative colonization (fecal microbiota transplant) may eventually become part of a bundle approach to reduce CRE infections in the future. As in non-transplant patients, CRE infections in the transplant setting are challenging to treat and prevent. Infection prevention and control remains crucial to prevent widespread dissemination, and unique challenges exist with donor-derived CRE and how best to manage recipients in the peri-transplant period. Newer treatments are now in early-phase clinical studies, and in vitro activity data are supportive for several agents providing hope for improved outcomes with these typically difficult-to-treat and highly morbid infections in transplant recipients.

Donor-derived infections, lessons learnt from the past, and what is the future going to bring us

PURPOSE OF REVIEW

Donor-derived transmission of infectious diseases is a well-recognized complication of solid organ transplantation (SOT). Most donor-derived disease transmissions are expected. Although uncommon, unexpected donor-derived infections can be associated with significant morbidity and mortality, and as the volume of patients undergoing SOT increases, the number of infections transmitted through organ donation can also be expected to rise. The growing gap between the number of patients waiting for transplantation and available organs continue in fact to be the number one issue facing the transplant community. As a consequence the major focus in organ transplantation has been developing strategies to increase the available organs, including the use of organs from donors with infections or risky behaviors that have disqualified them from the donation in the past.

RECENT FINDINGS

In addition to the commonly reported donor-derived transmissions, an increasing number of studies have reported unusual infections transmitted by SOT.

SUMMARY

Transplant surgeons and physicians should increase their awareness toward uncommon donor-derived infections including them in the differential diagnosis of unusual clinical pictures in their recipients.

The prevention of hepatitis C virus transmission to hemodialysis patients and staff members

In this review article, we cover 4 topics very relevant to those involved in the care of hemodialysis (HD) patients and in the management of a HD unit. We start with an overview of the progress made over the last 25 years to reduce hepatitis C virus (HCV) transmission in HD. Next, we discuss the potential strategies to prevent the residual ongoing transmission of HCV to HD patients. Third, we discuss the actions to be taken if a seroconversion for HCV is nevertheless detected in a HD patient. Finally, we briefly discuss how best to protect HD staff members from occupationally acquired HCV infection.

Infections among pediatric transplant candidates: An approach to decision-making

INTRODUCTION

The presence of infections in the immediate pretransplant period poses challenges in decision-making. Delaying transplantation because of these infections may be required, but is associated with a risk to the potential recipient. The aim of this project was to develop a structured framework based on expert opinion to guide decision-making regarding the safety of transplantation for candidates with infection immediately before transplant, and to show how this framework can be applied to clinical scenarios.

METHODS

Categories were created as follows: Category A: no delay; Category B: brief delay (≤1 week); Category C: intermediate delay (>1 week); and Category D: more prolonged or indefinite delay. A survey containing 59 clinical scenarios was sent to members of the IPTA ID CARE committee. Answers were reviewed, and the level of agreement was characterized as follows: Level 1: ≥75% agreement; Level 2:51%-74% agreement; and Level 3: ≤50% agreement. 95% CIs were calculated for the mean overall agreement across 59 scenarios.

RESULTS

Among the panel, the agreement level ranged from 33% to 92% with the mean overall agreement across the 59 scenarios being 61%. For 7/59 scenarios, the lower bound of 95% CI was greater than 50%, indicating a difference at the 5% level of significance between the observed proportion and the chance level of 0.5.

SUMMARY

The document provides expert opinion regarding the need to delay transplantation in the setting of different infections. The most important points in the decision to proceed to SOT included the urgency of transplantation and the severity of infection.

Donor-derived Viral Infections in Liver Transplantation

Donor-derived infections are defined as any infection present in the donor that is transmitted to 1 or more recipients. Donor-derived infections can be categorized into 2 groups: "expected" and "unexpected" infections. Expected transmissions occur when the donor is known to have an infection, such as positive serology for cytomegalovirus, Epstein Barr virus, or hepatitis B core antibody, at the time of donation. Unexpected transmissions occur when a donor has no known infection before donation, but 1 or more transplant recipients develop an infection derived from the common donor. Unexpected infections are estimated to occur in far less than 1% of solid organ transplant recipients. We will review the epidemiology, risk factors, and approaches to prevention and management of donor-derived viral infectious disease transmission in liver transplantation.

Seroprevalence of Strongyloides stercoralis and Evaluation of Universal Screening in Kidney Transplant Candidates: A Single-Center Experience in Houston (2012-2017)

Background

Disseminated strongyloidiasis in solid organ transplant recipients is a rare but devastating infection. In our center, we implemented a universal screening of all candidates for kidney transplantation. We assessed the seroprevalence and utility of universal screening for strongyloidiasis in our center.

Methods

Patients were identified from our transplant referral list (from July 2012 to June 2017). Demographics, pretransplant laboratory, and serological screenings were retrospectively collected. For Strongyloides-seropositive (SSp) patients, data on travel history, symptoms, treatment, and stool ova and parasite examinations were extracted. Logistic regression and multiple imputation for missing data were performed.

Results

A total of 1689 patients underwent serological screening, of whom 168 (9.9%) were SSp. Univariate analysis revealed that SSp patients had higher rates of eosinophilia, diabetes mellitus, latent tuberculosis and were likely to be either Hispanic or Asian (P < .05). In multivariate analysis, eosinophilia (P = .01), diabetes mellitus (P = .02), and Asian race (P = .03) were associated with being SSp, but 45 (27%) of the SSp patients did not have any of these 3 factors, and 18 SSp patients (11%) had no epidemiological risk factors. All patients received ivermectin, and none developed disseminated strongyloidiasis. Of patients who underwent serological screening on multiple occasions, 6.8% seroconverted while waiting for kidney transplantation.

Conclusions

We found a high rate of Strongyloides seropositivity among our kidney transplantation candidates. No epidemiological risk factors effectively predicted SSp status in our population, and universal screening identified a large number of patients without such factors. Serial screening should be considered when a long wait time is expected before transplantation.

Urinary tract 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 urinary tract infections (UTI) in solid organ transplantation, focusing on kidney transplant (KT) recipients. KT recipients have unique risk factors for UTI, including indwelling stents and surgical manipulation of the genitourinary tract. KT recipients experience multi-drug antibiotic-resistant infections-UTI prevention and management strategies must consider risks of antimicrobial resistance. Non-antimicrobial prevention strategies for UTI in KT recipients are reviewed. It is important to recognize that some renal transplant recipients with UTI may primarily present with fever, malaise, leukocytosis, or a non-specific sepsis syndrome without symptoms localized to the urinary tract. However, asymptomatic bacteriuria (AB) must be distinguished from UTI because AB is not necessarily a disease state. Accumulating data indicate that there are no benefits of antibiotics for treatment of AB in KT recipients more than 2 months after post-transplant. Further research is needed on management of AB in the early (<2 months) post-transplant period, prophylaxis for UTI in this era of antibiotic resistance, recurrent UTI, non-antimicrobial prevention of UTI, and uropathogens identified in donor urine and/or preservative fluid cultures.

Viral Diagnostics

This chapter discusses recent developments in diagnostics for cytomegalovirus (CMV), Epstein-Barr virus (EBV), BK virus (BKV), community respiratory viruses (CRVs), parvovirus, hepatitis viruses, HIV, and other viral agents of importance in solid organ and hematopoietic stem cell transplantation.

Infectious Disease Transmission in Solid Organ Transplantation: Donor Evaluation, Recipient Risk, and Outcomes of Transmission

In 2016, the Transplantation Society of Australia and New Zealand, with the support of the Australian Government Organ and Tissue authority, commissioned a literature review on the topic of infectious disease transmission from deceased donors to recipients of solid organ transplants. The purpose of this review was to synthesize evidence on transmission risks, diagnostic test characteristics, and recipient management to inform best-practice clinical guidelines. The final review, presented as a special supplement in Transplantation Direct, collates case reports of transmission events and other peer-reviewed literature, and summarizes current (as of June 2017) international guidelines on donor screening and recipient management. Of particular interest at the time of writing was how to maximize utilization of donors at increased risk for transmission of human immunodeficiency virus, hepatitis C virus, and hepatitis B virus, given the recent developments, including the availability of direct-acting antivirals for hepatitis C virus and improvements in donor screening technologies. The review also covers emerging risks associated with recent epidemics (eg, Zika virus) and the risk of transmission of nonendemic pathogens related to donor travel history or country of origin. Lastly, the implications for recipient consent of expanded utilization of donors at increased risk of blood-borne viral disease transmission are considered.

Infections in Liver Transplantation

Liver transplantation has become an important treatment modality for patients with end-stage liver disease/cirrhosis, acute liver failure, and hepatocellular carcinoma. Although surgical techniques and immunosuppressive regimens for liver transplantation have improved significantly over the past 20 years, infectious complications continue to contribute to the morbidity and mortality in this patient population. The use of standardized screening protocols for both donors and recipients, coupled with targeted prophylaxis against specific pathogens, has helped to mitigate the risk of infection in liver transplant recipients. Patients with chronic liver disease and cirrhosis have immunological deficits that place them at increased risk for infection while awaiting liver transplantation. The patient undergoing liver transplantation is prone to develop healthcare-acquired infections due to multidrug-resistant organisms that could potentially affect patient outcomes after transplantation. The complex nature of liver transplant surgery that involves multiple vascular and hepatobiliary anastomoses further increases the risk of infection after liver transplantation. During the early post-transplantation period, healthcare-acquired bacterial and fungal infections are the most common types of infection encountered in liver transplant recipients. The period of maximal immunosuppression that occurs at 1–6 months after transplantation can be complicated by opportunistic infections due to both primary infection and reactivation of latent infection. Severe community-acquired infections can complicate the course of liver transplantation beyond 12 months after transplant surgery. This chapter provides an overview of liver transplantation including indications, donor-recipient selection criteria, surgical procedures, and immunosuppressive therapies. A focus on infections in patients with chronic liver disease/cirrhosis and an overview of the specific infectious complications in liver transplant recipients are presented.

Is This Organ Donor Safe?: Donor-Derived Infections in Solid Organ Transplantation

Infection is an inevitable complication of solid organ transplantation. Unrecognized infection may be transmitted from a donor and result in disseminated disease in the immunosuppressed host. Recent outbreaks of deceased donor-derived infections resulting in high rates of mortality and severe morbidity have emphasized the need to be cautious in using donors with possible meningoencephalitis. Screening of organ donors for potential transmissible infections is paramount to improving transplantation outcomes.

Is This Organ Donor Safe?: Donor-Derived Infections in Solid Organ Transplantation

Infection is an inevitable complication of solid organ transplantation. Unrecognized infection may be transmitted from a donor and result in disseminated disease in the immunosuppressed host. Recent outbreaks of deceased donor-derived infections resulting in high rates of mortality and severe morbidity have emphasized the need to be cautious in using donors with possible meningoencephalitis. Screening of organ donors for potential transmissible infections is paramount to improving transplantation outcomes.

Use of Organs From Hepatitis C Virus-Positive Donors for Uninfected Recipients: A Potential Cost-Effective Approach to Save Lives?

BACKGROUND

Organs from hepatitis C virus (HCV) seropositive (HCVpos) individuals are seldom used for transplantation because of the risk of disease transmission. Because transmitted HCV is now amenable to effective treatment, we estimated the potential impact of using HCVpos deceased donor organs for transplantation.

METHODS

The Potential Donor Audit of patients (<80 years) dying in UK critical care units and the UK Transplant Registry was searched to identify HCVpos potential and proceeding deceased donors. Donor organ quality was assessed using validated donor organ quality indices. Cost analysis was performed by comparing the cumulative cost of direct-acting antivirals with hemodialysis and renal transplantation.

RESULTS

Between 2009 and 2016, 120 patients identified from the Potential Donor Audit were not considered as potential donors because of the presence of HCV. Between 2000 and 2015, 244 HCVpos potential deceased donors were identified from the UK Transplant Registry, and 76 (31%) proceeded to donation, resulting in 63 liver, 27 kidney, and 2 heart transplants. Recipient and graft survival was not adversely impacted by donor HCVpos status. Most (69%) offered organs were declined because of positive virology although their quality was similar to that of other transplanted organs. The additional costs of treating recipients exposed to HCV by receiving a HCVpos kidney was cost-neutral with dialysis 5 years from transplantation.

CONCLUSIONS

HCVpos donors represent a potential source of organs for HCV seronegative recipients as many good quality HCVpos donor organs are not currently used for transplantation. This change in practice may increase access to transplantation without having an adverse effect on transplant outcome.