Changes in the spectrum and risk factors for invasive candidiasis in liver transplant recipients: prospective, multicenter, case-controlled study

Incidence, causative organisms, and risk factors of bloodstream infections in pediatric liver transplant patients: a systematic review

Bacterial bloodstream infections (BSI) are the leading cause of mortality and morbidity in pediatric solid organ transplant recipients. This systematic review aimed to pool global data from leading transplant institutions and identify the overall incidence, risk factors, and causative organisms of BSI in pediatric liver transplant recipients. A systematic review of the PubMed and OVID databases was conducted from 2000 to 2022. The initial search yielded 252 unique articles, which were independently reviewed by 2 authors. Articles that reported pediatric-specific data on BSI in isolated liver transplant patients were included, including the incidence of BSI, isolated organisms, and involved risk factors involved. This systematic review was registered with PROSPERO (ID: CRD42023403206). Fourteen articles from the United States, France, Iran, Japan, Korea, South Africa, Thailand, and Turkey were included. A total of 4,812 liver transplants were included in the final analysis. The mean patient age was 25 months (age range, 0-18 years), and 50.9% were male. The overall incidence of BSI was 23.5% (range, 14.7%-55%). The most commonly reported organisms were Staphylococcus epidermidis, Enterococcus, Klebsiella spp., and Escherichia coli. Among the risk factors studied, postope rative biliary complications, a medical history of biliary atresia, and younger age were the risk factors most commonly associated with BSI. Bacterial BSI after pediatric liver transplantation occur at a high incidence, with a unique organism profile notable for a higher percentage of gram-negative organisms. Further studies are required to determine the most appropriate prophylactic and empirical antibiotic management strategies for this population.

The predictors of fungal infections after liver transplantation and the influence of fungal infections on outcomes

The primary objective of this study was to assess the incidence, timing, risk factors of fungal infections (FIs) within 3 months after liver transplantation (LT). The secondary objective was to evaluate the impact of FIs on outcomes. Four hundred and ten patients undergoing LT from January 2015 until January 2023 in a tertiary university hospital were included in the present retrospective cohort study to investigate the risk factors of FIs and to assess the impacts of FIs on the prognosis of LT recipients using logistic regression. The incidence of FIs was 12.4% (51/410), and median time from LT to the onset of FIs was 3 days. By univariate analysis, advanced recipient age, prolonged hospital stay prior to LT, high Model for End Stage Liver Disease (MELD) score, use of broad-spectrum antibiotics, and elevated white blood cell (WBC) count, increased operating time, massive blood loss and red blood cell transfusion, elevated alanine aminotransferase on day 1 and creatinine on day 3 after LT, prolonged duration of urethral catheter, prophylactic antifungal therapy, the need for mechanical ventilation and renal replacement therapy were identified as factors of increased post-LT FIs risk. Multivariate logistic regression analysis identified that recipient age ≥ 55 years[OR = 2.669, 95%CI: 1.292-5.513, P = 0.008], MELD score at LT ≥ 22[OR = 2.747, 95%CI: 1.274-5.922, P = 0.010], pre-LT WBC count ≥ 10 × 109/L[OR = 2.522, 95%CI: 1.117-5.692, P = 0.026], intraoperative blood loss ≥ 3000 ml [OR = 2.691, 95%CI: 1.262-5.738, P = 0.010], post-LT duration of urethral catheter > 4 d [OR = 3.202, 95%CI: 1.553-6.602, P = 0.002], and post-LT renal replacement therapy [OR = 5.768, 95%CI: 1.822-18.263, P = 0.003] were independently associated with the development of post-LT FIs. Post-LT prophylactic antifungal therapy ≥ 3 days was associated with a lower risk of the development of FIs [OR = 0.157, 95%CI: 0.073-0.340, P < 0.001]. As for clinical outcomes, FIs had a negative impact on intensive care unit (ICU) length of stay ≥ 7 days than those without FIs [OR = 3.027, 95% CI: 1.558-5.878, P = 0.001] but had no impact on hospital length of stay and 1-month all-cause mortality after LT. FIs are frequent complications after LT and the interval between the onset of FIs and LT was short. Risk factors for post-LT FIs included high MELD score at LT, advanced recipient age, pre-LT WBC count, massive intraoperative blood loss, prolonged post-LT duration of urethral catheter, and the need for post-LT renal replacement therapy. However, post-LT prophylactic antifungal therapy was independently associated with the reduction in the risk of FIs. FIs had a significant negative impact on ICU length of stay.

Risk Factors for Early Fungal Disease in Solid Organ Transplant Recipients: A Systematic Review and Meta-analysis

BACKGROUND

Invasive fungal infections are associated with high morbidity in solid organ transplant recipients. Risk factor modification may help with preventative efforts. The objective of this study was to identify risk factors for the development of fungal infections within the first year following solid organ transplant.

METHODS

We searched for eligible articles through February 3, 2023. Studies published after January 1, 2001, that pertained to risk factors for development of invasive fungal infections in solid organ transplant were reviewed for inclusion. Of 3087 articles screened, 58 were included. Meta-analysis was conducted using a random-effects model to evaluate individual risk factors for the primary outcome of any invasive fungal infections and invasive candidiasis or invasive aspergillosis (when possible) within 1 y posttransplant.

RESULTS

We found 3 variables with a high certainty of evidence and strong associations (relative effect estimate ≥ 2) to any early invasive fungal infections across all solid organ transplant groups: reoperation (odds ratio [OR], 2.92; confidence interval [CI], 1.79-4.75), posttransplant renal replacement therapy (OR, 2.91; CI, 1.87-4.51), and cytomegalovirus disease (OR, 2.97; CI, 1.78-4.94). Both posttransplant renal replacement therapy (OR, 3.36; CI, 1.78-6.34) and posttransplant cytomegalovirus disease (OR, 2.81; CI, 1.47-5.36) increased the odds of early posttransplant invasive aspergillosis. No individual variables could be pooled across groups for invasive candidiasis.

CONCLUSIONS

Several common risk factors exist for the development of any invasive fungal infections in solid organ transplant recipients. Additional risk factors for invasive candidiasis and aspergillosis may be unique to the pathogen, transplanted organ, or both.

Culture-independent diagnostic approaches for invasive aspergillosis in solid organ transplant recipients

Prompt and accurate diagnosis of invasive aspergillosis (IA) is crucial for immunocompromised patients, including those who have received a solid organ transplant (SOT). Despite their low sensitivity, microscopic detection and conventional culture are considered the 'gold standard' methods. In conjunction with conventional culture, culture-independent assays such as serum galactomannan testing and Aspergillus polymerase chain reaction (PCR) have been incorporated into the diagnostic process for IA. The recently revised consensus definitions from the European Organization for Research and Treatment of Cancer and the Mycosis Study Group have adjusted the threshold for positive galactomannan testing based on the sample type, and have excluded 1,3-β-D-glucan testing as a mycological criterion. Following extensive standardization efforts, positive Aspergillus PCR tests using serum, plasma, or bronchoalveolar lavage fluid have been added. However, there are limited studies evaluating the clinical utility of these culture-independent assays for the early diagnosis of IA in SOT recipients. Therefore, further research is required to determine whether these assays could aid in the early diagnosis of IA in SOT recipients, particularly in relation to the organ transplanted. In this review, we examine the culture-independent diagnostic methods for IA in SOT recipients, as well as the clinical utility of these assays.

Invasive fungal infections in liver diseases

Patients with liver diseases, including decompensated cirrhosis, alcohol-associated hepatitis, and liver transplant recipients are at increased risk of acquiring invasive fungal infections (IFIs). These infections carry high morbidity and mortality. Multiple factors, including host immune dysfunction, barrier failures, malnutrition, and microbiome alterations, increase the risk of developing IFI. Candida remains the most common fungal pathogen causing IFI. However, other pathogens, including Aspergillus, Cryptococcus, Pneumocystis, and endemic mycoses, are being increasingly recognized. The diagnosis of IFIs can be ascertained by the direct observation or isolation of the pathogen (culture, histopathology, and cytopathology) or by detecting antigens, antibodies, or nucleic acid. Here, we provide an update on the epidemiology, pathogenesis, diagnosis, and management of IFI in patients with liver disease and liver transplantation.

Invasive Fungal Infections: The Early Killer after Liver Transplantation

BACKGROUND

Liver transplantation is a standard of care and a life-saving procedure for end-stage liver diseases and certain malignancies. The evidence on predictors and risk factors for poor outcomes is lacking. Therefore, we aimed to identify potential risk factors for mortality and to report on overall 90-day mortality after orthotopic liver transplantation (OLT), especially focusing on the role of fungal infections.

METHODS

We retrospectively reviewed medical charts of all patients undergoing OLT at a tertiary university center in Europe.

RESULTS

From 299 patients, 214 adult patients who received a first-time OLT were included. The OLT indication was mainly due to tumors (42%, 89/214) and cirrhosis (32%, 68/214), including acute liver failure in 4.7% (10/214) of patients. In total, 8% (17/214) of patients died within the first three months, with a median time to death of 15 (1-80) days. Despite a targeted antimycotic prophylaxis using echinocandins, invasive fungal infections occurred in 12% (26/214) of the patients. In the multivariate analysis, patients with invasive fungal infections had an almost five times higher chance of death (HR 4.6, 95% CI 1.1-18.8; p = 0.032).

CONCLUSIONS

Short-term mortality after OLT is mainly determined by infectious and procedural complications. Fungal breakthrough infections are becoming a growing concern. Procedural, host, and fungal factors can contribute to a failure of prophylaxis. Finally, invasive fungal infections may be a potentially modifiable risk factor, but the ideal perioperative antimycotic prophylaxis has yet to be determined.

Antifungals: From Pharmacokinetics to Clinical Practice

The use of antifungal drugs started in the 1950s with polyenes nystatin, natamycin and amphotericin B-deoxycholate (AmB). Until the present day, AmB has been considered to be a hallmark in the treatment of invasive systemic fungal infections. Nevertheless, the success and the use of AmB were associated with severe adverse effects which stimulated the development of new antifungal drugs such as azoles, pyrimidine antimetabolite, mitotic inhibitors, allylamines and echinochandins. However, all of these drugs presented one or more limitations associated with adverse reactions, administration route and more recently the development of resistance. To worsen this scenario, there has been an increase in fungal infections, especially in invasive systemic fungal infections that are particularly difficult to diagnose and treat. In 2022, the World Health Organization (WHO) published the first fungal priority pathogens list, alerting people to the increased incidence of invasive systemic fungal infections and to the associated risk of mortality/morbidity. The report also emphasized the need to rationally use existing drugs and develop new drugs. In this review, we performed an overview of the history of antifungals and their classification, mechanism of action, pharmacokinetic/pharmacodynamic (PK/PD) characteristics and clinical applications. In parallel, we also addressed the contribution of fungi biology and genetics to the development of resistance to antifungal drugs. Considering that drug effectiveness also depends on the mammalian host, we provide an overview on the roles of therapeutic drug monitoring and pharmacogenomics as means to improve the outcome, prevent/reduce antifungal toxicity and prevent the emergence of antifungal resistance. Finally, we present the new antifungals and their main characteristics.

Invasive Fungal Infections after Liver Transplantation

Invasive fungal infections represent a major challenge in patients who underwent organ transplantation. Overall, the most common fungal infections in these patients are candidiasis, followed by aspergillosis and cryptococcosis, except in lung transplant recipients, where aspergillosis is most common. Several risk factors have been identified, which increase the likelihood of an invasive fungal infection developing after transplantation. Liver transplant recipients constitute a high-risk category for invasive candidiasis and aspergillosis, and therefore targeted prophylaxis is favored in this patient population. Furthermore, a timely implemented therapy is crucial for achieving optimal outcomes in transplanted patients. In this article, we describe the epidemiology, risk factors, prophylaxis, and treatment strategies of the most common fungal infections in organ transplantation, with a focus on liver transplantation.

Invasive Fungal Breakthrough Infections under Targeted Echinocandin Prophylaxis in High-Risk Liver Transplant Recipients

Invasive fungal infections (IFIs) are frequent and outcome-relevant complications in the early postoperative period after orthotopic liver transplantation (OLT). Recent guidelines recommend targeted antimycotic prophylaxis (TAP) for high-risk liver transplant recipients (HR-LTRs). However, the choice of antimycotic agent is still a subject of discussion. Echinocandins are increasingly being used due to their advantageous safety profile and the increasing number of non-albicans Candida infections. However, the evidence justifying their use remains rather sparse. Recently published data on breakthrough IFI (b-IFI) raise concerns about echinocandin efficacy, especially in the case of intra-abdominal candidiasis (IAC), which is the most common infection site after OLT. In this retrospective study, we analyzed 100 adult HR-LTRs undergoing first-time OLT and receiving echinocandin prophylaxis between 2017 and 2020 in a tertiary university hospital. We found a breakthrough incidence of 16%, having a significant impact on postoperative complications, graft survival, and mortality. The reasons for this may be multifactorial. Among the pathogen-related factors, we identified the breakthrough of Candida parapsilosis in 11% of patients and one case of persistent IFI due to the development of a secondary echinocandin resistance of an IAC caused by Candida glabrata. Consequently, the efficacy of echinocandin prophylaxis in liver transplantation should be questioned. Further studies are necessary to clarify the matter of breakthrough infections under echinocandin prophylaxis.

Incidence of Invasive Fungal Infections in Liver Transplant Recipients under Targeted Echinocandin Prophylaxis

Invasive fungal infections (IFIs) are one of the most important infectious complications after liver transplantation, determining morbidity and mortality. Antimycotic prophylaxis may impede IFI, but a consensus on indication, agent, or duration is still missing. Therefore, this study aimed to investigate the incidence of IFIs under targeted echinocandin antimycotic prophylaxis in adult high-risk liver transplant recipients. We retrospectively reviewed all patients undergoing a deceased donor liver transplantation at the Medical University of Innsbruck in the period from 2017 to 2020. Of 299 patients, 224 met the inclusion criteria. We defined patients as being at high risk for IFI if they had two or more prespecified risk factors and these patients received prophylaxis. In total, 85% (190/224) of the patients were correctly classified according to the developed algorithm, being able to predict an IFI with a sensitivity of 89%. Although 83% (90/109) so defined high-risk recipients received echinocandin prophylaxis, 21% (23/109) still developed an IFI. The multivariate analysis identified the age of the recipient (hazard ratio-HR = 0.97, p = 0.027), split liver transplantation (HR = 5.18, p = 0.014), massive intraoperative blood transfusion (HR = 24.08, p = 0.004), donor-derived infection (HR = 9.70, p < 0.001), and relaparotomy (HR = 4.62, p = 0.003) as variables with increased hazard ratios for an IFI within 90 days. The fungal colonization at baseline, high-urgency transplantation, posttransplant dialysis, bile leak, and early transplantation showed significance only in a univariate model. Notably, 57% (12/21) of the invasive Candida infections were caused by a non-albicans species, entailing a markedly reduced one-year survival. The attributable 90-day mortality rate of an IFI after a liver transplant was 53% (9/17). None of the patients with invasive aspergillosis survived. Despite targeted echinocandin prophylaxis, there is still a notable risk for IFI. Consequently, the prophylactic use of echinocandins must be critically questioned regarding the high rate of breakthrough infections, the increased occurrence of fluconazole-resistant pathogens, and the higher mortality rate in non-albicans Candida species. Adherence to the internal prophylaxis algorithms is of immense importance, bearing in mind the high IFI rates in case algorithms are not followed.

Infective Artery Rupture of Renal Allografts: A Single-Center Retrospective Study in China

OBJECTIVE

This study investigated the composition of pathogenic microorganisms, clinical features, and therapeutic strategies of infective artery rupture of renal allografts in recipients receiving deceased donor (DD) kidneys.

METHODS

We retrospectively studied the clinical data of the DD kidney transplant recipients with donor-associated infection at Tongji Hospital, Wuhan, China from January 1, 2015 to December 31, 2018, related recipients and corresponding donors. We collected the entire results of pathogenic microorganisms cultured from these related ruptured kidneys and then analyzed their distribution and differences.

RESULTS

A total of 1440 kidney transplants from DD were performed in our center. The total incidence of infective artery rupture in kidney transplants was about 0.76% (11/1440), and the annual incidence ranged from 0.25% to 1.03%. The microbial culture results revealed that 11 recipients suffered from infective artery rupture and 3 recipients who accepted the kidney from same donor had the donor-associated pathogens, including 9 fungal strains (28.1%) and 23 bacterial strains (71.9%). There were 4 recipients infected with multi-drug-resistant Staphylococcus and Klebsiella pneumoniae from the above 11 recipients, of which, 10 recipients underwent graft loss, and one died of septic shock. The microbial cultures of the remaining 3 recipients who received appropriate anti-infective regimens turned negative eventually, and the patients were discharged successfully without significant complications.

CONCLUSION

Renal recipients with infections derived from DDs were at high risk of artery rupture, graft loss, or even death. Appropriate anti-infective treatment is essential to reduce the incidence of artery rupture and mortality.

Risk factors of invasive fungal infections in liver transplant recipients: A systematic review and meta-analysis

Invasive fungal infections (IFIs) remain one of the most common infectious complications after organ transplantation, and liver transplant recipients (LTRs) have the highest mortality rate. However, risk factors associated with IFIs have only been evaluated in small single-center studies. We performed a meta-analysis by conducting a comprehensive search using Ovid MEDLINE, Ovid Embase, Cochrane database of systematic reviews, and Cochrane central register of controlled trials. All case-control and cohort studies evaluating risk factors for IFIs in adult LTRs were screened. Utilizing a random-effects model, a multivariate analysis was completed, and 28 studies were eligible for meta-analysis. Rates of IFIs ranged from 1.4% to 32.7%. Previous antibiotic use (OR 9.3; 95% CI 3.2-27.0) and bacterial infection (OR 4.3; 95% CI 2.1-8.6) were risk factors of invasive candidiasis. Yet for invasive aspergillosis, posttransplant renal replacement therapy (OR 9.2; 95% CI 4.2-20.4), reoperation (OR 8.0; 95% CI 2.9-21.7), and cytomegalovirus infection (OR 6.2; 95% CI 2.0-19.3) were risk factors. The top independent risk factors for IFIs during studies from 2010 to 2019 were previous fungal colonization (OR 9.19; 95% CI 4.92-17.16), reoperation (OR 5.45; 95% CI 2.93-10.15), and previous bacterial infections (OR 3.81; 95% CI 2.13-6.83). These risk factors may be targeted by antifungal prophylaxis in LTRs.

Fungal infections following liver transplantation

With increasing morbidity and mortality from chronic liver disease and acute liver failure, the need for liver transplantation is on the rise. Most of these patients are extremely vulnerable to infections as they are immune-compromised and have other chronic co-morbid conditions. Despite the recent advances in practice and improvement in diagnostic surveillance and treatment modalities, a major portion of these patients continue to be affected by post-transplant infections. Of these, fungal infections are particularly notorious given their vague and insidious onset and are very challenging to diagnose. This mini-review aims to discuss the incidence of fungal infections following liver transplantation, the different fungi involved, the risk factors, which predispose these patients to such infections, associated diagnostic challenges, and the role of prophylaxis. The population at risk is increasingly old and frail, suffering from various other co-morbid conditions, and needs special attention. To improve care and to decrease the burden of such infections, we need to identify the at-risk population with more robust clinical and diagnostic parameters. A more robust global consensus and stringent guidelines are needed to fight against resistant microbes and maintain the longevity of current antimicrobial therapies.

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.

Catastrophic Brain Aspergillosis after Liver Transplantation

Background. Liver transplantation has many complications. Because of receiving immunosuppressive regimens, infectious complications in these patients may have fatal results. Aspergillosis in solid organ recipients is one of the most common fungal infections that usually occur 1 month after transplantation. Aspergillus infection mainly involves the lungs. Although the central nervous system may get involved due to hematogenous spreading from lungs, isolated central nervous system involvement is rarely reported. Case Presentation. The patient was an 8-year-old boy, with a case of Wilson disease, who underwent liver transplantation due to acute fulminant hepatic failure. Four days after the surgery, he was affected by fever, agitation, loss of consciousness, hemiparesis, and focal seizure. Brain MRI showed abscess formation, whereas chest X-ray was normal. Intravenous antibiotics were initiated but the patient's condition was not improving; therefore, surgical drainage of the abscess was performed. The pathological investigation was compatible with aspergillosis. Antifungal therapy with voriconazole was administrated. His symptoms were resolved but unfortunately, brain lesions caused persistent vegetative state. Discussion. Aspergillus is a ubiquitous organism that mainly occurs in immunocompromised patients. Aspergillosis could be prevented by environmental modification such as installing high-efficiency particulate air filters. Chemoprevention with triazoles, echinocandins, and polyenes is also effective. Voriconazole is the drug of choice for aspergillosis treatment. Although voriconazole is a highly effective antifungal drug, cerebral aspergillosis is often fatal.

Soluble intercellular adhesion molecule (ICAM)-1 detects invasive fungal infections in patients following liver transplantation

PURPOSE

Despite antifungal prophylaxis, liver transplanted patients are endangered by invasive fungal infections (IFI). Routinely used microbiological procedures are hallmarked by significant weaknesses, which may lead to a delay in antifungal treatment.

METHODS

Culture-based fungal findings, routinely used biomarkers of infection/inflammation (e.g., procalcitonin or C-reactive protein), as well as corresponding plasma concentrations of soluble Intercellular Adhesion Molecule (ICAM)-1 were analysed in 93 patients during a period of 28 days following liver transplantation (LTX).

RESULTS

Plasmatic sICAM-1 was significantly elevated in patients affected by an IFI within the first 28 days in comparison to fungally colonised or unobtrusive LTX patients. sICAM-1 might therefore be helpful for the identification of IFI patients after LTX (e.g., Receiver Operating Characteristic (ROC)-Area Under the Curve (AUC): 0.714 at 14d after LTX). The diagnostic performance of sICAM-1 was further improved by its combined use with different other IFI biomarkers (e.g., midregional proadrenomedullin).

CONCLUSION

The diagnostic deficiencies of routinely used microbiological procedures for IFI detection in patients after LTX may be reduced by plasmatic sICAM-1 measurements. Clinical Trial Notation. German Clinical Trials Register: DRKS00005480.

Beta-D-Glucan Levels With Use of an Anti-adhesion Barrier Film in Pediatric Living Donor Liver Transplantation

INTRODUCTION

Serum beta-D-glucan (BDG) levels may increase with anti-adhesion barrier film (ABF) use during pediatric living donor liver transplantation (LDLT). It may affect detection of fungal infections after LDLT. We evaluate BDG levels after pediatric LDLT.

METHODS

Pediatric patients who received an ABF during LDLT were included. Patients who may have had fungal infections prior to LDLT were excluded. One sheet of ABF was placed in the peritoneum during abdominal closure. Serum BDG levels before transplantation and on postoperative days (PODs) 1, 4, 7, 14, 21, and 28 and peritoneal fluid BDG levels on PODs 1 and 7 were measured.

RESULTS

Sixteen patients received an ABF during LDLT. Median age at transplant was 1.9 years (range, 6-11 years). Median body weight was 12.6 kg (range, 6.8-39 kg). Indications for LDLT were biliary atresia (n = 10) and other (n = 5). Prior to transplantation, the mean serum BDG level was 3.8 pg/mL. Mean Serum BDG levels were 18.1, 38.3, 5.3, 3.8, 3.3, and 3.3 pg/mL on PODs 1, 4, 7, 14, 21, and 28, respectively. Mean peritoneal fluid BDG levels were 485.9 and 240.4 pg/mL on PODs 1 and 7, respectively. No clinical fungal infections were observed.

CONCLUSIONS

BDG levels were high in serum and peritoneal fluid after pediatric LDLT. Serum BDG levels normalized after POD 7. Careful interpretation of BDG levels until POD 7 is needed when an ABF has been used.

Invasive Fungal Infections With Good Survival Following Liver Transplant: A Single-Center Experience From a Developing Country

OBJECTIVES

Invasive fungal infection following liver transplant is considered as one of the important factors influencing morbidity and mortality among liver transplant recipients. The aim of the present study was to describe the prevalence of invasive fungal infections and their predisposing factors in a singlecenter cohort of patients who received liver transplant.

MATERIALS AND METHODS

For this study, 250 adult patients undergoing orthotopic liver transplant between March 2010 and March 2015 were enrolled. All patients were followed prospectively for infections.

RESULTS

The diagnosis of invasive fungal infection was made in 15 patients (6%). One patient had 2 episodes of fungal infection, and reoperation was performed for 3 patients. Invasive aspergillosis developed in 8 patients (53.3%),followed by Candida species infection in 3 patients (20%) and cryptococcosis in 2 patients (13.3%).The main predisposing factors were renal failure (12/15) and positive history of rejection (11/15). Other risk factors for development of invasive fungal infections were choledochojejunostomy in 3 patients (20%), bile leaks in 3 patients (20%), and pretransplant steroid use in 2 patients (11.8%). Two patients (13.3%) died due to invasive fungal infections.

CONCLUSIONS

In this single-center series of liver transplant recipients, the incidence of invasive fungal infections was relatively low, probably due to the universal prophylaxis with fluconazole and limited use of the broad-spectrum antibiotics. Early diagnosis and treatment of invasive fungal infections could lead to a better prognosis for liver transplant recipients with invasive fungal infections.

New approaches for the detection of invasive fungal diseases in patients following liver transplantation-results of an observational clinical pilot study

PURPOSE

Despite antifungal prophylaxis following liver transplantation (LTX), patients are at risk for the development of subsequent opportunistic infections, such as an invasive fungal disease (IFD). However, culture-based diagnostic procedures are associated with relevant weaknesses.

METHODS

Culture and next-generation sequencing (NGS)-based fungal findings as well as corresponding plasma levels of ß-D-glucan (BDG), galactomannan (GM), interferon gamma (IFN-γ), tumor necrosis factor alpha (TNF-α), interleukin (IL)-2, -4, -6, -10, -17A and mid-regional proadrenomedullin (MR-proADM) were evaluated in 93 patients at 6 consecutive time points within 28 days following LTX.

RESULTS

A NGS-based diagnostic approach was shown to be suitable for the early identification of fungal pathogens in patients following LTX. Moreover, MR-proADM and IL-17A in plasma proved suitable for the identification of patients with an IFD.

CONCLUSION

Plasma measurements of MR-proADM and IL-17A as well as a NGS-based diagnostic approach were shown to be attractive methodologies to attenuate the weaknesses of routinely used culture-based diagnostic procedures for the determination of an IFD in patients following LTX. However, an additional confirmation within a larger multicenter trial needs to be recommended.

TRIAL REGISTRATION

German Clinical Trials Register: DRKS00005480 .

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.

Yeast Infections in Solid Organ Transplantation

Invasive candidiasis (IC) remains the most common invasive fungal infection following solid-organ transplant (SOT), but risk factors are evolving. Current challenges include infection due to drug resistant non-albicans and emerging novel species such as Candida auris. Preventive antifungal use in SOT needs to be re-examined in light of these current challenges. Cryptococcosis is the second most common IFI following SOT. Cryptococcus gattii is an emerging pathogen that can have reduced in-vitro susceptibility to antifungal agents. Cryptococcus associated IRIS in SOT is a clinical entity that warrants heightened awareness for timely recognition and management.

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

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

Epidemiology, risk factors and outcomes of invasive aspergillosis in solid organ transplant recipients in the Swiss Transplant Cohort Study

BACKGROUND

There is lack of recent multicenter epidemiological data on invasive aspergillosis (IA) among solid organ transplant recipient (SOTr) in the mold-acting antifungal era. We describe the epidemiology and outcomes of IA in a contemporary cohort of SOTr using the Swiss Transplant Cohort Study.

METHODS

All consecutive SOTr with proven or probable IA between 01.05.2008 and 31.12.2014 were included. A case-control study to identify IA predictors was performed: 1-case was matched with 3-controls based on SOT type, transplant center, and time post-SOT.

RESULTS

Among 2868 SOTr, 70 (2.4%) patients were diagnosed with proven (N: 30/70, 42.9%) or probable (N: 40/70, 57.1%) IA. The incidence of IA was 8.3%, 7.1%, 2.6%, 1.3%, and 1.2% in lung, heart, combined, kidney, and liver transplant recipients, respectively, Galactomannan immunoassay was positive in 1/3 of patients tested. Only 33/63 (52.4%) of patients presented with typical pulmonary radiographic findings. Predictors of IA included: renal insufficiency, re-operation, and bacterial and viral infections. 12-week mortality was higher in liver (85.7%, 6/7) compared to other (15.9%, 10/63; P < .001) SOTr.

CONCLUSIONS

Invasive aspergillosis remains a rare complication post-SOT, with atypical radiographic presentations and low positivity rates of biomarkers posing significant diagnostic challenges. Although overall mortality has decreased in SOTr, it remains high in liver SOTr.

Risk Analysis for Invasive Fungal Infection after Living Donor Liver Transplantation: Which Patient Needs Potent Prophylaxis?

BACKGROUND

Invasive fungal infection (IFI) is associated with high mortality after living donor liver transplant (LDLT). The aim of this study was to identify the risk factors for post-LDLT IFI for early diagnosis and improvement of antifungal treatment outcome.

METHODS

Risk analysis data were available for all 153 patients who underwent LDLT between January 2005 and April 2012.

RESULTS

During the follow-up period (1,553 ± 73 days, range 20-2,946 days), 15 patients (9.8%) developed IFI classified as "proven" (n = 8) and "probable" (n = 7) with fungal pathogens including Candida spp. (n = 10), Aspergillus spp. (n = 4), and Trichosporon (n = 2). Of these patients, 7 patients with IFI died despite treatment. The 1-, 3-, and 5-year survival rates were lower in patients with IFI than those without IFI (66.7/59.3/44.4 vs. 90.4/85.7/81.8%, respectively; p = 0.0026). Multivariate analysis identified model for end-stage liver disease score of ≥26 (OR 16.0, p = 0.0012) and post-transplant acute kidney injury (RIFLE criteria I- or F-class; OR 4.87, p = 0.047) as independent risk factors for IFI.

CONCLUSION

Preoperative recipients' status and postoperative kidney dysfunction can affect an occurrence of post-transplant IFI. These risk factors would be taken into consideration for designation of proper antifungal therapy.

Effects of infection on post-transplant outcomes: living versus deceased donor liver transplants

Introduction

Post-transplant infections have been studied widely but data on comparisons of deceased donor liver transplants (DDLT) and living donor liver transplants (LDLT), type and timings of infections, and their relations to outcomes are not explored.

Material and methods

We analysed data from 612 participants of the Adult-to-Adult Living Donor Liver Transplantation Study (A2ALL), a retrospective data set of LDLT and DDLT. We compared the type and timing of the first post-transplant infection in relation to transplant outcomes between the two groups.

Results

Out of 611 patients, 24.5% experienced the first post-transplant infection, the majority of which were bacterial (35.3%), followed by fungal (11%) and viral infections (4.2%). There was no significant difference in the rate, type or timing of infection between LDLT and DDLT. Patients with late (> 1 year) first infection were 1.8 times more likely to die (95% CI: 1.12-2.98, p = 0.015) and 9 times more likely to have graft failures (95% CI: 3.26-24.8, p < 0.001). DDLT recipients who experienced bacterial infection had a significantly lower survival rate compared to LDLT recipients (p < 0.001).

Conclusions

Late infection is associated with lower survival in both DDLT and LDLT. Bacterial infection might be more detrimental for DDLT than LDLT. Late infection should be managed aggressively to improve outcomes.

Infectious diseases in solid organ transplant recipients: Analysis of autopsied cases in Japan

BACKGROUND

With the improvements in immunosuppressive agents and graft survival, infections such as mycoses have become major complications after solid organ transplantation (SOT).

METHODS

Our group has continuously updated an epidemiological database of visceral mycoses (VM) among autopsy cases in Japan since 1989. Data on infectious agents and clinical information were complied using similar procedures.

RESULTS

Among the all autopsied cases studied, 356 undergone SOT. Of these, 214 (60.1%) suffered from one or more types of infections, including 51 (14.3%) with VM. Thus, the incidence of VM was higher in SOT recipients than in non-transplanted cases (P < 0.0001). Aspergillus spp. (Asp) was the most predominant agent and Candida spp. was second. Specifically, among SOT recipients, Asp was the most predominant in liver and lung transplant recipients. Among the 217 autopsied liver transplants cases, the incidence of VM was highest in those with fulminant hepatitis (FH, P = 0.01). The incidence of cytomegalovirus infection tended to be higher in cases with mycosis (P = 0.06). Multivariate logistic regression analysis identified FH (odds ratio, 3.61, 95% confidence interval 1.34-9.75; P = 0.03) as an independent risk factor for mycosis in liver transplant recipients.

CONCLUSION

This epidemiological analysis of autopsied cases provides a strong incentive to intensify efforts to diagnose and treat post-SOT infectious diseases.

Invasive Candida Infections in Liver Transplant Recipients: Clinical Features and Risk Factors for Mortality

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Background

Invasive fungal infections remain a leading cause of morbidity and mortality among liver transplant recipients (LTRs). In this patient population, invasive Candida infections (ICIs) account for the large majority of cases. To date, only small studies and case-series analysing clinical presentation and risk factors for mortality in LTRs with ICIs are available.

Methods

We performed a retrospective multicenter multinational study in 10 centers in Europe and Brazil. All consecutive LTRs developing ICIs during the period January 2011 to December 2013 were included in the study.

Results

A total of 42 LTRs were included. Median age was 52.5 years, and 78.6% of patients were men. Viral hepatitis was the most common cause for liver transplantation (42.9%). Candidemia represented the majority of cases (24, 57.1%), followed by intra-abdominal candidiasis (18, 42.9%). Overall 30-day mortality was 23.8%, with higher mortality in patients with candidemia compared with intra-abdominal candidiasis (37.5% vs 5.6%, P = 0.02). Multivariate analysis showed candidemia to be a risk factor associated with mortality among LTRs presenting ICIs (odds ratio, 11.86; 95% confidence interval, 1.5-280; P = 0.01). Candida albicans represented the most common isolate (59.5%). High rates of antifungal resistances were found, with 16.7% and 4.8% of isolates displaying resistance to azoles and caspofungin, respectively.

Conclusions

Our study confirms the occurrence of high mortality rates in LTRs developing ICIs. Mortality rates varied according to the type of infection, with candidemia representing a risk factor for mortality. The high rates of antifungal resistance should be considered in the choice of the empiric antifungal regimen.

The epidemiology and outcomes of invasive Candida infections among organ transplant recipients in the United States: results of the Transplant-Associated Infection Surveillance Network (TRANSNET)

BACKGROUND

Invasive candidiasis (IC) is a common cause of mortality in solid organ transplant recipients (OTRs), but knowledge of epidemiology in this population is limited.

METHOD

The present analysis describes data from 15 US centers that prospectively identified IC from nearly 17 000 OTRs. Analyses were undertaken to determine predictors of infection and mortality.

RESULTS

A total of 639 cases of IC were identified. The most common species was Candida albicans (46.3%), followed by Candida glabrata (24.4%) and Candida parapsilosis (8.1%). In 68 cases >1 species was identified. The most common infection site was bloodstream (44%), followed by intra-abdominal (14%). The most frequently affected allograft groups were liver (41.1%) and kidney (35.3%). All-cause mortality at 90 days was 26.5% for all species and was highest for Candida tropicalis (44%) and C. parapsilosis (35.2%). Non-white race and female gender were more commonly associated with non-albicans species. A high rate of breakthrough IC was seen in patients receiving antifungal prophylaxis (39%). Factors associated with mortality include organ dysfunction, lung transplant, and treatment with a polyene antifungal. The only modifiable factor identified was choice of antifungal drug class based upon infecting Candida species.

CONCLUSION

These data highlight the common and distinct features of IC in OTRs.

Complications of invasive mycoses in organ transplant recipients

INTRODUCTION

Opportunistic mycoses remain a significant complication in organ recipients. Areas covered: This review is an evidence-based presentation of current state-of-knowledge and our perspective on recent developments in the field Expert commentary: Invasive fungal infections are associated with reduced allograft and patient survival, increase in healthcare resource utilization, and newly appreciated but largely unrecognized immunologic sequelae, such as immune reconstitution syndrome. Given adverse outcomes associated with established infections, prophylaxis is a widely used strategy for the prevention of these infections. Currently available biomarkers that detect circulating fungal cell wall constituents i.e., galactomannan and 1, 3-β-D-glucan have not proven to be beneficial as screening tools for employing targeted prophylaxis or as diagnostic assays in this patient population. However, subsets of patients at risk for opportunistic fungal infections can be identified based on clinically identifiable characteristics or events. Preventive strategies targeted towards these patients are a rational approach for optimizing outcomes.

Invasive candidiasis in liver transplant patients: Incidence and risk factors in a pediatric cohort

Prolonged OR, re-transplantation, and high-volume intraoperative transfusion have been associated with increased risk for IC in adult LT recipients. Antifungal prophylaxis is recommended for adult patients with these risk factors. There are limited data on the incidence of and risk factors for IC in pediatric LT recipients. A retrospective cohort study of all pediatric LT patients at the CHOP between 2000 and 2012 and the CHP between 2004 and 2012 was performed to define the incidence of IC within 30 days of LT. A 3:1 matched case-control study with incidence density sampling was performed. Conditional logistic regression analyses were used to explore risk factors associated with IC. Among 397 recipients, the incidence of IC was 2.5%. Bivariate analyses showed that ICU admission prior to transplant, OR > 10 h, intraoperative volume infusion of >300 mL/kg, and broad-spectrum antibiotics were significantly associated with IC. In a multivariate model, only ICU admission remained significantly associated with IC. Antifungal prophylaxis was not significantly protective against IC. The low incidence of IC and lack of an identified protective effect from antifungal prophylaxis suggest that prophylaxis in pediatric LT recipients should not be routinely recommended to prevent IC events in the first 30 days post-transplant.

Bloodstream infections after solid-organ transplantation

Solid-organ transplantation (SOT) has become the preferred strategy to treat a number of end-stage organ disease, because a continuous improvement in survival and quality of life. While preventive strategies has decreased the risk for classical opportunistic infections (such as viral, fungal and parasite infections), bacterial infections, and particularly bloodstream infections (BSIs) remain the most common and life-threatening complications in SOT recipients. The source of BSI after transplant depends on the type of transplantation, being urinary tract infection, pneumonia, and intraabdominal infections the most common infections occurring after kidney, lung and liver transplantation, respectively. The risk for candidemia is higher in abdominal-organ than in thoracic-organ transplantation. Currently, the increasing prevalence of multi-drug resistant (MDR) Gram-negative pathogens, such as extended-spectrum betalactamase-producing Enterobacteriaciae and carbapenem-resistant Klebsiella pneumoniae, is causing particular concerns in SOT recipients, a population which presents several risk factors for developing infections due to MDR organisms. The application of strict preventive policies to reduce the incidence of post transplant BSIs and to control the spread of MDR organisms, including the implementation of specific stewardship programs to avoid the overuse of antibiotics and antifungal drugs, are essential steps to reduce the impact of post transplant infections on allograft and patient outcomes.

Fungal infections after liver transplantation: incidence and outcome

BACKGROUND

Fungal infections, although less frequent than bacterial infections, represent a severe comorbidity with an exponential increase in mortality rate in liver transplantation patients. The incidence of invasive fungal infections (IFIs) after solid organ transplantation ranges from 7% to 42%, with Candida spp. and Aspergillus spp. as the most common pathogens. Fungal infections in liver transplant recipients have been associated with poor outcome and mortality rates ranging from 65% to 90% for invasive aspergillosis and 30% to 50% for invasive candidiasis. The results largely depend on early diagnosis and early initiation of specific treatment for IFIs. Therefore, the diagnosis must be prompt, preferably based on microbiological data, both cultures and biomarkers, and/or based on clinical features and known risk factors.

MATERIALS AND METHODS

This study evaluated the incidence of fungal infections in patients after liver transplantation in our center between January 2003 and December 2012. The retrospective analysis of 215 consecutive liver transplantation patients was undertaken to estimate incidence, risk factors, and clinical courses of IFIs in the first 3 months after liver transplantation.

RESULTS

Candidemia and invasive candidiasis microbiologically proven were found in 26 patients (12%), whereas in 6 patients (2.8%) invasive fungal infections from other non-Candida fungi developed: Aspergillus (4 cases: 2 A fumigatus, 2 A terreus), Fusarium oxysporum (1 case), and Rhodotorula rubra (1 case). Two patients with Aspergillus and the patient with Fusarium died. The patient with Rhodotorula as well as 22 of the patients with candidemia (85%) survived. All of the episodes developed during the first 3 months posttransplantation. All cases have followed a previous polymicrobial bacterial infection (especially in the biliary tract) with large use of combined antibiotic therapies.

CONCLUSIONS

The rate of fungal infection was found to increase in parallel with the number of risk factors. Prophylactic strategies can decrease the risk of fungal infections. Early detection and treatment with adequate early empiric therapy is the key to obtaining a better outcome in liver transplantation patients.

Prophylactic use of liposomal amphotericin B in preventing fungal infections early after liver transplantation: a retrospective, single-center study

In this study the authors evaluated the efficacy of prophylaxis with liposomal amphotericin B (L-AmB) in the incidence of fungal infections (FI) during the first 3 months after liver transplant (LT). The study was retrospective and accessed a 4-year period from 2008 to 2011. All patients who died in the first 48 hours after LT were excluded. Patients were divided by the risk groups for FI: Group 1, high-risk (at least 1 of the following conditions: urgent LT; serum creatinine >2 mg/dL; early acute kidney injury [AKI] after LT; retransplantation; surgical exploration early post-LT; transfused cellular blood components [>40 U]); and Group 2, low-risk patients. Group 1 patients were further separated into those who received antifungal prophylaxis with L-AmB and those who did not. Prophylaxis with L-AmB consisted of intravenous administration of L-AmB, 100 mg daily for 14 days. Four hundred ninety-two patients underwent LT; 31 died in the first 48 hours after LT. From the remaining 461 patients, 104 presented with high-risk factors for FI (Group 1); of these, 66 patients received antifungal prophylaxis and 38 did not. In this group 8 FI were observed, 5 in patients without antifungal prophylaxis (P = .011). Three more FI were identified in Group 2. By logistic regression analysis, the categorical variable high-risk group was independently related to the occurrence of invasive FI (P = .006). We conclude that prophylaxis with L-AmB after LT was effective in reducing the incidence of FI. No influence on mortality was detected.

Targeted versus universal antifungal prophylaxis among liver transplant recipients

Guidelines recommend targeted antifungal prophylaxis for liver transplant (LT) recipients based on tiers of risk, rather than universal prophylaxis. The feasibility and efficacy of tiered, targeted prophylaxis is not well established. We performed a retrospective study of LT recipients who received targeted prophylaxis (n = 145; voriconazole [VORI; 54%], fluconazole [8%], no antifungal [38%]) versus universal VORI prophylaxis (n = 237). Median durations of targeted and universal prophylaxis were 11 and 6 days, respectively (p < 0.0001). The incidence of invasive fungal infections (IFIs) in targeted and universal groups was 6.9% and 4.2% (p = 0.34). Overall, intra-abdominal candidiasis (73%) was the most common IFI. Posttransplant bile leaks (p = 0.001) and living donor transplants (p = 0.04) were independent risk factors for IFI. IFIs occurred in 6% of high-risk transplants who received prophylaxis and 4% of low-risk transplants who did not receive prophylaxis (p = 1.0). Mortality rates (100 days) were 10% (targeted) and 7% (universal) (p = 0.26); attributable mortality due to IFI was 10%. Compliance with prophylaxis recommendations was 97%. Prophylaxis was discontinued for toxicity in 2% of patients. Targeted antifungal prophylaxis in LT recipients was feasible and safe, effectively prevented IFIs and reduced the number of patients exposed to antifungals. Bile leaks and living donor transplants should be considered high-risk indications for prophylaxis.

Antifungal prophylaxis in liver transplantation: a systematic review and network meta-analysis

Invasive fungal infections (IFIs) cause significant morbidity and mortality in liver transplant recipients, but the need and best agent for prophylaxis is uncertain. A comprehensive literature search was performed to identify randomized controlled trials comparing regimens for antifungal prophylaxis in liver transplant recipients. Direct comparisons were made between treatments using random-effects meta-analysis and a Bayesian network meta-analysis was performed for the primary end point of proven IFI. Fourteen studies met inclusion criteria, reporting comparisons of fluconazole, liposomal amphotericin B (L-AmB), itraconazole, micafungin and placebo. Overall, antifungal prophylaxis reduced the rate of proven IFI (odds ratio [OR] 0.37, confidence interval [CI] 0.19-0.72, p = 0.003), suspected or proven IFI (OR 0.40, CI 0.25-0.66, p = 0.0003) and mortality due to IFI (OR 0.32, CI 0.10-0.83, p = 0.02) when compared to placebo. All-cause mortality was not significantly affected. There was no difference in risk of adverse events requiring cessation of prophylaxis (OR 1.11, 95% CI 0.48-2.55, p = 0.81). In the network meta-analysis an equivalent reduction in the rate of IFI was seen with fluconazole (OR 0.21, CI 0.06-0.57) and L-AmB (OR 0.21, CI 0.05-0.71) compared with placebo. Routine prophylaxis with fluconazole or L-AmB reduces the incidence of IFI following liver transplantation, and the available evidence suggests that the two are equivalent in efficacy.

Infections after orthotopic liver transplantation

Opportunistic infections are a leading cause of morbidity and mortality after orthotopic liver transplantation. Systemic immunosuppression renders the liver recipient susceptible to de novo infection with bacteria, viruses and fungi post-transplantation as well to reactivation of pre-existing, latent disease. Pathogens are also transmissible via the donor organ. The time from transplantation and degree of immunosuppression may guide the differential diagnosis of potential infectious agents. However, typical systemic signs and symptoms of infection are often absent or blunted after transplant and a high index of suspicion is needed. Invasive procedures are often required to procure tissue for culture and guide antimicrobial therapy. Antimicrobial prophylaxis reduces the incidence of opportunistic infections and is routinely employed in the care of patients after liver transplant. In this review, we survey common bacterial, fungal, and viral infections after orthotopic liver transplantation and highlight recent developments in their diagnosis and management.

Surveillance of bacterial and fungal infections in the postoperative period following liver transplantation: a series from 2005-2011

Orthotopic liver transplantation (OLT) is a life-saving procedure for the treatment of many end-stage diseases, but infectious and acute rejection episodes remain major causes of morbidity and mortality. Bacterial and fungal infections can be due to intra-abdominal, biliary, respiratory, urinary, wound, central venous catheters (CVC) or unknown sources. Using the computerized database of our microbiology laboratory, we analyzed all the bacterial and fungal infections in the first three months following OLT among 151 consecutive adult recipients at single center between January 2005 and December 2011. Samples included blood, bile CVC, urine, and bronchoalveolar lavage (BAL) specimen. Culture and identification of the isolated microorganisms was done in accordance with standard microbiological procedures. Three hundred thirteen samples from the above sites showed positive results for gram-positive cocci (n = 137; 43.8%), gram-negative rods (n = 156; 49.8%), and Candida species (n = 19; 6.1%). One patient (0.3%) experienced a CVC-related infection caused by Fusarium oxysporum. Bacterial and particularly biliary tract infections seem to play major roles in morbidity and mortality in the first three months following OLT. The major contributors to patient morbidity and mortality were candidemia and/or invasive candidiasis mainly from the biliary tract and/or CVC-related infections.

Candida norvegensis fungemia in a liver transplant recipient

BACKGROUND

The incidence of candidemia due to non-Candida albicans Candida species has been progressively increasing in recent years. The use of fluconazole as antifungal prophylaxis has been described as a risk factor for the development of infections by fluconazole resistant Candida strains. We report a case of Candida norvegensis bloodstream infection in a liver transplant recipient.

CASE REPORT

A 61-year-old man, who received a third liver allograft and became worse with the onset of ischemic cholangiopathy and recurrent episodes of cholangitis, was admitted to our hospital due to the development of intra-abdominal abscesses. He received multiple antibiotic schemes, and after 3 months he was discharged, maintaining parenteral antibiotic at home. While he was on fluconazole prophylaxis, a breakthrough candidemia due to C. norvegensis occurred. In vitro susceptibilities of the isolate to several antifungal agents were as follows: amphotericin B MIC 0.5 mg/l, flucytosine 64 mg/l, fluconazole 64 mg/l, itraconazole 4 mg/l, voriconazole 0.75 mg/l, and caspofungin 0.047 mg/l. He was treated with anidulafungin with resolution of candidemia.

CONCLUSIONS

The use of fluconazole for antifungal prophylaxis may lead to the emergence of fluconazole-resistant Candida infections, with C. norvegensis being a possible emerging pathogen in organ transplant recipients.

Nosocomial infections within the first month of solid organ transplantation

Infections remain a common complication of solid organ transplantation. Early postoperative infections remain a significant cause of morbidity and mortality in solid organ transplant (SOT) recipients. Although significant effort has been made to understand the epidemiology and risk factors for early nosocomial infections in other surgical populations, data in SOT recipients are limited. A literature review was performed to summarize the current understanding of pneumonia, urinary tract infection, surgical-site infection, bloodstream infection, and Clostridium difficult colitis, occurring within the first 30 days after transplantation.

Emerging trends in infections among renal transplant recipients

Outcomes following renal and simultaneous kidney-pancreas transplants have improved significantly due to better surgical techniques and improved modalities of antirejection therapy. However, infection remains a significant cause of morbidity and mortality. The use of new modalities of immunosuppression and routine use of antimicrobial prophylaxis has changed the pattern of infections post-transplantation. Cytomegalovirus remains a significant problem and BK virus has emerged as an important pathogen. New antimicrobial agents are now available to treat infection, however, antimicrobial resistance remains a concern.