Pattern of bacterial and fungal infections in the first 3 months after pediatric living donor liver transplantation: an 11-year single-center experience

Surgical Site Infections After Pediatric Liver Transplantation-Impact of a Change in Perioperative Prophylactic Antibiotic Protocol

BACKGROUND

In spite of improved survival rates after pediatric liver transplantation, infections remain major contributors to perioperative morbidity and mortality. This study aimed to understand the impact of type and duration of perioperative antibiotic prophylaxis (PAP) on the occurrence of surgical site infections (SSIs).

METHODS

In total, 125 patients who underwent liver transplantation between 2014 and 2020 were retrospectively included. Patients were categorized into two periods based on changes in the standard PAP regimen. Risk factors for SSIs were investigated, including the influence of PAP duration, antibiotic substances used, and abdominal patch placement using multivariable regression models.

RESULTS

SSIs occurred in 23 (19%) of 119 analyzed patients and were not impacted by changes in the PAP regimen. The placement of an abdominal patch was a relevant risk factor for SSIs (odds ratio 3.81; 95% confidence interval [CI] 1.15-12.68). Longer PAP duration reduced the occurrence of SSIs by up to 4.6 percentage points (95% CI 0.0-9.1) per day, with its effect diminishing with longer duration. The choice of antibiotic substances for PAP changed after implementation of the new protocol, with a decline in vancomycin usage from 14% to 3%.

CONCLUSION

The results of this study emphasize the need for evidence-based PAP regimens tailored to the unique needs of pediatric liver transplant recipients. The occurrence of SSIs remains complex and is influenced by various factors beyond the PAP regimen. Multicentric efforts to develop effective prevention strategies against SSIs in this vulnerable population are warranted.

Epidemiology and Risk Factors of Early Bacterial Infections After Pediatric Living Donor Liver Transplantation

BACKGROUND

Advancements in surgical techniques, immunosuppression regimens, and peri-operative and postoperative care have resulted in marked improvement in outcomes after pediatric living donor liver transplantation (PLDLT). Despite these developments, infectious complications remain a major cause of morbidity and mortality.

METHODS

This is a retrospective cohort analysis of pediatric recipients from January 2004 to December 2018. Patients were classified into infected and non-infected groups based on the occurrence of bacterial infection during the first 3 months after transplant. Perioperative risk factors for early post-transplant bacterial infections and postoperative outcomes were investigated.

RESULTS

Seventy-two out of 221 children developed early bacterial infection (32.6%). The first episodes of bacterial infection most frequently occurred in the second week after LDLT (37.5%). In multivariate analysis, active infection before transplant and complications with Clavien-Dindo grading >3 were the only independent risk factors. Early bacterial infections were independently associated with longer intensive care unit stays, longer hospital stays, and a higher incidence of readmission for bacterial infection during the first year after transplant. Additionally, the overall patient survival rate was significantly higher in the non-infected group (P = .001). Risk factors for infection, such as age, weight, disease severity, ABO-incompatible, and other operative factors, were not identified as independent risk factors.

CONCLUSION

We have demonstrated that there are similarities and disparities in the epidemiology and risk factors for early bacterial infection after transplant between centers. Identification and better characterization of these predisposing factors are essential in the modification of current preventive strategies and treatment protocols to improve outcomes for this highly vulnerable group.

Pediatric Infectious Diseases Related to Transplantation: Insights From Japan

Infectious diseases after transplantation account for significant morbidity and mortality in children undergoing transplantation; the importance of pediatric transplant infectious disease (TID) specialists has therefore been recognized. Although tremendous advancement continues in transplantation medicine, pediatric-specific data and evidence are limited. In Japan, the majority of TIDs had not been managed by infectious disease specialists because pediatric infectious diseases have not been recognized as a solo subspecialty until recently in Japan. However, in the last decade, there was a new movement for pediatric TID in Japan; some pediatric infectious disease specialists trained outside Japan have been playing an important role in managing pediatric TID in a few academic and pediatric institutions. In this review article, we introduce the current status of infectious complications related to pediatric hematopoietic cell and solid organ transplantation, highlighting currently available local evidence, common practice and issues in the field of pediatric TID in Japan.

Epidemiology and outcomes of surgical site infections among pediatric liver transplant recipients

INTRODUCTION

Surgical site infections (SSI) are a significant cause of morbidity in liver transplant recipients, and the current data in the pediatric population are limited. The goal of this study was to identify the incidence, classification, risk factors, and outcomes of SSIs among children undergoing liver transplantation (LT).

METHODS

A single-center, retrospective descriptive analysis was performed of patients age ≤18 years undergoing LT between September 2007 and April 2017. SSI identified within the first 30 days were analyzed. Primary endpoints included incidence, classification, risk factors, and outcomes associated with SSIs.

RESULTS

We included 86 patients, eight patients (9.3%) developed SSIs. Among segmental grafts (SG) recipients, 7/61 (11.4%) developed SSI. Among whole grafts recipients, 1/25 (4%) developed SSI. SSIs were associated with the presence of biliary complications (35% vs. 3%, p < .01; odds ratios 24, 95% CI: 3.41-487.37, p<.01). There were no differences in long term graft or patient survival associated with SSI. Patients who developed SSI were more likely to undergo reoperation (50% vs. 16.7%, p = .045) and had an increased total number of hospital days in the first 60 days post-transplant (30.5 vs. 12.5 days, p = .001).

CONCLUSIONS

SSIs after pediatric LT was less frequent than what has been previously reported in literature. SSIs were associated with the presence of biliary complications without an increase in mortality. SG had an increased rate of biliary complications without an association to SSIs but, considering its positive impact on organ shortage barriers, should not be a deterrent to the utilization of SGs.

A single-center report of COVID-19 disease course and management in liver transplanted pediatric patients

BACKGROUND

In 2019, SARS-CoV-2 causing COVID-19 emerged. Severe COVID-19 symptoms may evolve by virtue of hyperactivation of the immune system. Equally, immunocompromised patients may be at increased risk to develop COVID-19. However, treatment guidelines for children following liver transplantation are elusive.

METHODS

As a liver transplantation center, we diagnosed and followed up 10 children (male/female: 8/2) with a median age of 8.5 years (IQR: 5.2-11.0), with COVID-19 post-liver transplant between March 2019 and December 2020. COVID-19 diagnosis was based on PCR test and or florid X-ray findings compatible with COVID-19 in the absence of other cause. We retrospectively collected clinical and laboratory data from electronic patient records following written consent from patients/parents.

RESULTS

Nine patients were diagnosed as definitive (PCR positive) with one patient being diagnosed as probable COVID-19. Seven patients recovered without any support whereas three were admitted for non-invasive oxygenation. Lymphopenia and/or high levels of serum IL-6 were detected in four patients. Six patients mounted anti-SARS-CoV-2 antibodies at median 30 days (IQR: 26.5-119.0) following COVID-19 diagnosis. Antibiotic therapy, favipiravir, anakinra, and IVIG were used as treatment in 4,1,1 and 2 patients, respectively. Furthermore, we kept the tacrolimus with or without everolimus but stopped MMF in 2 patients. Importantly, liver allograft function was retained in all patients.

CONCLUSIONS

We found that being immunocompromised did not affect disease severity nor survival. Stopping MMF yet continuing with tacrolimus was an apt treatment modality in these patients.

Bacterial infections in children after liver transplantation: A single-center surveillance study of 345 consecutive transplantations

BACKGROUND

Infectious complications after pediatric liver transplantation frequently occur and are potentially serious. Data concerning strictly defined bacterial infections and their associated risk factors are lacking.

METHODS

For the pediatric liver transplant postoperative period, we analyzed data from the nosocomial infection surveillance (2006-2015).

RESULTS

A total of 235 bacterial infections in 162 transplantations (47%) occurred, including 32 bacterial pneumonia cases, 104 surgical site infections, 27 urinary tract infections, and 40 bloodstream infections. Sepsis was diagnosed in 127 cases (54%), severe sepsis in 22 (9%) cases, and septic shock in 41 (17%) cases. Thirty patients (9%) died, and septic shock was the leading cause of death. The carrier status of multi-drug resistant bacteria and a tacrolimus level >20 ng/mL were independent risk factors for surgical site infections and the occurrence of severe sepsis or septic shock. The length of mechanical ventilation was an independent risk factor for pneumonia and surgical site infection.

CONCLUSION

Bacterial infections in the early postoperative period after pediatric liver transplantation are associated with high morbidity and mortality. Physicians involved in the medical care of these patients should be aware of the specific risk factors, and further development of prevention programs is highly recommended.

Analysis of Bacterial and Fungal Infections after Cytoreduction Surgery and Hyperthermic Intraperitoneal Chemotherapy: An Observational Single-Centre Study

Introduction

While hyperthermic intraperitoneal chemotherapy (HIPEC) after cytoreduction surgery (CRS) has been shown to improve patient survival and disease-free progression in peritoneal carcinoma (PC) patients, the procedure relates to a high postoperative infection rate. Herein, we report the bacterial and fungal infections after CRS and HIPEC from a single institution in Saudi Arabia.

Patients and Methods

A prospective observational study was conducted on 38 patients with PC selected for CRS/HIPEC procedure between 2012 and 2015 in our centre.

Results

Postoperative bacterial and fungal infection within 100 days was 42.2%, bacterial infection was reported always, and fungal infection was reported in 5 (13.2%) cases. Infections from the surgical site were considered the most common infection site. Multidrug-resistant extended-spectrum beta-lactamase (ESBL) Escherichia coli was the most frequent isolate, followed by multidrug-resistant Acinetobacter baumannii and Pseudomonas aeruginosa. Lower preoperative albumin and a prolonged preoperative activated partial thromboplastin time (APTT) are associated with postoperative infections, while a prolonged preoperative hospital stay (hazard ratio (HR) = 1.064; confidence interval (CI) = 1.002–1.112; P=0.042) and more intraoperative blood loss (>10%) (HR = 3.919; 95% CI = 1.024–14.995; P=0.046) were independent risk factors for postoperative infections. Three cases died during the follow-up period; all were due to infection.

Discussion

The infection rate in our centre compared to previous studies of comparable patients was matching. Effective management of postoperative infections should be considered, and identified risk factors in this study can help to focus on effective prevention and treatment strategies.

Clinical course of human herpesvirus 6 infection in pediatric living donor liver transplantation

Differentiation between active and latent viral infection is critical for analysis of HHV-6-associated disease. HHV-6 infection has been associated with several clinical manifestations; however, the precise role of HHV-6 in pediatric LDLT remains unclear. This retrospective cohort study included 33 pediatric patients who received LDLT. All of the recipients were monitored for HHV-6 infection using viral isolation and real-time PCR. HHV-6 infection was observed in 14 of 33 (42.4%) recipients, and HHV-6B infection occurred within 2 weeks after LDLT in 10 of 14 (71.4%) recipients. HHV-6 was isolated from 10 of 33 (30.3%) recipients. Multivariate analysis showed that independent predictors of HHV-6B infection were age (OR 0.975; 95% CI 0.943-0.999; P = .041), PELD (OR 1.091; P = .038), and biliary atresia (OR 16.48; P = .035). The occurrence of unexplained fever was significantly higher in recipients with HHV-6B infection (11/14) compared with uninfected recipients (6/19) (P = .013). Additionally, ALT levels at 8 and 9 weeks after transplantation were significantly higher in the recipients with HHV-6B infection. Younger age, high MELD/PELD score, and biliary atresia as an underlying disease were identified as risk factors for viral infection.

Case report: retroperitoneal aspergilloma in a patient with rheumatoid arthritis presenting as malignant tumor

Background

Aspergillosis in patients with impaired immunity usually presents with invasive pulmonary infection and dissemination to a variety of organs via hematogenous spread. Aspergilloma in the retroperitoneal cavity is a rare disease with only a few cases reported in the literature. To the best of our knowledge, the present case of a retroperitoneal aspergilloma with no surgical history is only the second report in the literature.

Case presentation

A 65 year-old man, who had been receiving immunosuppressive treatment for rheumatoid arthritis with vasculitis for 9 years, was referred to the Urology Department with a retroperitoneal mass. This was confirmed by computed tomography performed during treatment for pulmonary aspergilloma. Because it was not possible to rule out malignant disease (e.g., liposarcoma), surgical exploration was performed. Pathological examination revealed aspergillus hyphae with fat necrosis, and retroperitoneal aspergilloma was diagnosed and appropriately treated. The tumor did not recur subsequently.

Conclusion

Our present case emphasizes that pharmacological treatments for aspergilloma in the retroperitoneal cavity have poor drug transitivity, so the relative effectiveness of pharmacological response is not useful for differentiating retroperitoneal aspergilloma from malignant disease.

Characteristics and Risk Factors of Late-onset Bloodstream Infection Beyond 6 Months After Liver Transplantation in Children

BACKGROUND

Bloodstream infection (BSI) is a major cause of morbidity and mortality after pediatric liver transplantation (LT). However, most studies have focused on BSI occurring within a few months after LT. In this study, we evaluated the characteristics of BSI occurring beyond 6 months after pediatric LT.

METHODS

We conducted a retrospective cohort study at a pediatric LT center in Japan from November 2005 to March 2016. We evaluated the causative organisms and site of late-onset BSI in children ≤ 18 years of age. The risk factors for developing late-onset BSI and the associations of late-onset BSI with long-term outcomes were also evaluated.

RESULTS

Three hundred forty cases of LT were evaluated. Thirty-eight BSI developed in 29 (9%) LT recipients. There were 42 organisms (nine Gram-positive cocci, 33 Gram-negative rods) isolated from the blood cultures of recipients with late-onset BSI. The most frequent sites of late-onset BSI was intraabdominal infection (18/38; 47%). There were also 14 (39%) episodes with no apparent focus. In multivariate analysis, a prolonged operative time > 12 hours (odds ratio [OR] = 3.55; P = 0.04) and biliary stenosis (OR = 4.60; P = 0.006) were independent risk factors for developing late-onset BSI. Late-onset BSI was associated with increased retransplantation rate (P = 0.04) and mortality (P < 0.001).

CONCLUSION

Late-onset BSI developed in 9% of recipients after pediatric LT. Gram-negative rods accounted for the majority of late-onset BSI as a consequence of abdominal infection, but the focus was often unclear. Prolonged operative time at LT and biliary stenosis were independent risk factors for developing late-onset BSI.

Epidemiological Analysis of Extended-Spectrum Beta-Lactamase-Producing Bacterial Infections in Adult Live Donor Liver Transplant Patients

Introduction:

Bacterial infections are a leading cause of morbidity and mortality in patients receiving solid-organ transplants. Extended-spectrum beta-lactamases (ESBL) pathogens are the most important pathogenic bacteria infecting these patients.

Aim:

This study aims to evaluate for the incidence and characteristics of ESBL-positive organism, to look for the clinical outcomes in ESBL-positive infected cases, and to evaluate and draft the antibiotic policy in posttransplant patients during the first 28 days posttransplant.

Materials and Methods:

This is a retrospective data analysis of liver transplant recipients infected with ESBL culture-positive infections. All the culture sites such as blood, urine, and endotracheal tube aspirates were screened for the first ESBL infection they had and noted. This data were collected till day 28 posttransplant. The antibiotic susceptibility pattern and the most common organism were also noted.

Results:

A total of 484 patients was screened and 116 patients had ESBL-positive cultures. Out of these, 54 patients had infections and 62 patients were ESBL colonizers. The primary infection site was abdominal fluid (40.7%), with Klebsiella accounting for most of the ESBL infections. Colistin was the most sensitive antibiotic followed by tigecycline. The overall mortality was 11.4% and 31 out of 54 ESBL-infected patients died.

Conclusions:

Infections with ESBL-producing organism in liver transplant recipients has a high mortality and very limited therapeutic options.

DCD liver transplant infection: experience from a single centre in China

AIM

The purpose of our study was to evaluate the incidence, timing, location and risk factors for bacterial and fungal infections after donation after cardiac death (DCD) liver transplant and clearly delineate any relationship between infection and survival in DCD liver transplant recipients.

METHODS

We retrospectively reviewed 257 consecutive patients undergoing DCD liver transplant between October 2010 and May 2015 at our centre.

RESULTS

A total of 133 patients (51.8%) developed at least one bacterial or fungal infection episode. The predominant infection site was the respiratory tract, followed by the blood stream. Most of the infections occurred within the first week after liver transplant (61.9%). A recipient respiratory support time greater than 7 days (p = 0.041), post-transplant hospital time greater than 24 days (p = 0.002) and renal failure after DCD liver transplant (p = 0.039) were independent predictors of bacterial and fungal infection. The area under the receiver operating characteristic (ROC) curve (AUC) of the transplant infection risk assessment model was 0.788. The 1- and 3-year survival rates for recipients without infection were significantly increased compared with recipients with infection (96.1% and 89.0% vs. 81.5% and 75.9%, p = 0.007).

CONCLUSION

This is the first study that offers detailed data revealing the timing and incidence of bacterial and fungal infection among adult DCD liver transplant recipients. Bacterial and fungal infection occurs at a high rate during the first week after DCD liver transplant, especially in patients with prolonged respiratory support time and renal failure, and infection is related to increased hospital stay.

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.

Outcome of Hepatitis B Virus Infection After Living-Donor Liver Transplant: A Single-center Experience Over 20 Years

OBJECTIVES

Despite living-donor liver transplant being a life-saving therapy for patients with hepatitis B virus with or without hepatocellular carcinoma, outcomes for patients with these diseases are worse. Hepatitis B virus recurrence or relapse of hepatocellular carcinoma can result in subsequent graft loss or patient death. In this study, we discuss the postoperative outcomes of patients with hepatitis B virus infection after living-donor liver transplant.

MATERIALS AND METHODS

We retrospectively analyzed 125 patients with hepatitis B virus-related end-stage liver disease, comparing results with 1228 control patients who had other pathologies, including hepatitis C virus, combined hepatitis B virus and hepatitis C virus, and neither virus.

RESULTS

Survival rates of patients with hepatitis B virus did not differ from the control groups (P > .05). Patients with concurrent hepatitis B virus and hepatocellular carcinoma were significantly older (P < .0001), had critical status (P < .0001), had chronic underlying pathology (P = .001), lower graft-to-recipient body weight ratio (P = .047), needed more intraoperative plasma transfusion, and experienced more rejection episodes than those without hepatocellular carcinoma. Of interest, in 5 patients who had hepatitis B virus recurrence after living-donor liver transplant, Model for End-Stage Liver Disease score was significantly higher than those who did not have recurrence (P = .015). In addition, 2 patients had hepatocellular carcinoma recurrence in the form of peritoneal metastasis, with both patients having high preoperative alpha-fetoprotein levels.

CONCLUSIONS

Our study provides details on long-term outcomes of patients with hepatitis B virus infection who had undergone living-donor liver transplant. Based on our results, we suggest that prolonged antiviral prophylactic therapy in the form of hepatitis B immunoglobulin with either lamivudine or entecavir be considered for patients who associated with risk factors to prevent postoperative recurrence.

Risk factors and outcomes of carbapenem-resistant Klebsiella pneumoniae infections in liver transplant recipients

Carbapenem-resistant Klebsiella pneumoniae (CRKP) infection is increasing in incidence and is associated with increased mortality in liver transplantation (LT) recipients. We performed a retrospective cohort study of all patients transplanted between January 2010 and January 2013 to identify the incidence and risk factors for post-LT CRKP infection and evaluate the impact of this infection on outcomes in a CRKP-endemic area. We studied 304 recipients, of whom 20 (6.6%) developed CRKP and 36 (11.8%) carbapenem-susceptible Klebsiella pneumoniae (CSKP) infections in the year following LT. Among the 20 recipients with post-LT CRKP infection, 8 (40%) were infected in ≥ 2 sites; 13 (65%) had surgical site-intra-abdominal infections; 12 (60%) had pneumonia; and 3 (15%) had a urinary tract infection. There were 6 patients with a CRKP infection before LT, 5 of whom developed a CRKP infection after LT. Significant risk factors for post-LT CRKP infection in multivariate analysis included laboratory Model for End-Stage Liver Disease at LT (odds ratio [OR], 1.07; P = 0.001), hepatocellular carcinoma (OR, 3.19; P = 0.02), Roux-en-Y biliary choledochojejunostomy (OR, 3.15; P = 0.04), and bile leak (OR, 5.89; P = 0.001). One-year estimated patient survival was 55% (95% confidence interval, 31%-73%), 72% (55%-84%), and 93% (89%-96%), for patients with CRKP, CSKP, and no Klebsiella pneumoniae infection, respectively. In multivariate analysis, CRKP (hazard ratio [HR], 6.92; P < 0.001) and CSKP infections (CSKP, HR, 3.84; P < 0.001), as well as bile leak (HR, 2.10; P = 0.03) were the strongest predictors of post-LT mortality. In an endemic area, post-LT CRKP infection is common, occurring in 6.6% of recipients, and is strongly associated with post-LT mortality. Improved strategies for screening and prevention of CRKP infection are urgently needed.

Changes in Surgical Site Infections after Living Donor Liver Transplantation

Surgical site infections (SSIs) are a major threat for liver transplant recipients. We prospectively studied SSIs after living donor liver transplantation (LDLT) at Kyoto University Hospital from April 2001 to March 2002 (1st period) and from January 2011 to June 2012 (2nd period). We investigated the epidemiology of SSIs after LDLT and determined the differences between the two periods. A total of 129 adult recipients (66 during the 1st period and 63 during the 2nd period) and 72 pediatric recipients (39 and 33) were included in this study. The SSI rates for each period were 30.3% (1st period) and 41.3% (2nd period) among the adult recipients and 25.6% and 30.3% among the pediatric recipients. The overall rates of 30-day mortality among adult transplant recipients with SSIs were 10.0% (1st period) and 3.9% (2nd period). No pediatric recipient died from SSIs after LDLT in either period. The incidence of Enterococcus faecium increased from 5.0% to 26.9% in the adults and from 10.0% to 40.0% in the pediatric patients. Extended-spectrum β-lactamase-producing Enterobacteriaceae were emerging important isolates during the 2nd period. For this period, a univariate analysis showed that ABO incompatibility (P = 0.02), total operation duration (P = 0.01), graft-to-recipient body weight ratio (GRWR [P = 0.04]), and Roux-en-Y biliary reconstruction (P<0.01) in the adults and age (P = 0.01) and NHSN risk index (P = 0.02) in the children were associated with SSI development. In a multivariate analysis, lower GRWR (P = 0.02) and Roux-en-Y biliary reconstruction (P<0.01) in the adults and older age (P = 0.01) in the children were independent risk factors for SSIs during the 2nd period. In conclusion, SSIs caused by antibiotic resistant bacteria may become a major concern. Lower GRWR and Roux-en-Y biliary reconstruction among adult LDLT recipients and older age among pediatric LDLT recipients increased the risk of developing SSIs after LDLT.

Staphylococcus aureus infections among children receiving a solid organ transplant: clinical features, epidemiology, and antimicrobial susceptibility

BACKGROUND

Staphylococcus aureus is among the most common causes of healthcare-associated infection (HAI) in the United States. Patients who have received a solid organ transplant (SOT) represent a unique population for the acquisition of HAIs, given their preoperative organ failure, immunosuppression, and need for invasive procedures. However, limited literature is published on S. aureus infections among children with SOT. We describe the epidemiology, antimicrobial susceptibility, and clinical features of S. aureus infections among pediatric SOT recipients.

DESIGN

An ongoing prospective S. aureus surveillance database from 2001 to 2012 was searched for infections in patients with a history of SOT at Texas Children's Hospital. Medical records and antibiotic susceptibility profiles were reviewed; specific attention was applied to the time since transplantation to infection.

RESULTS

Out of the total of 696 transplants performed during the study period, 38 pediatric SOT recipients developed 41 S. aureus infections; the highest incidence of infection was among heart recipients. Overall, the most common infectious diagnoses were skin-and-soft-tissue infections (66.1%), followed by bacteremia (15.3%). Among isolates in SOT patients, 47.5%, 16.9%, and 6.7% were resistant to methicillin, clindamycin, or mupirocin, respectively. Three infections (7.3%) occurred in the early post-transplant period (<1 month), all of which were bacteremia (P = 0.007) and all caused by methicillin-susceptible S. aureus (MSSA). The majority of infections (90.2%) occurred in the late post-transplant period (>6 months). In 10 cases (16.9%), S. aureus infection was associated with graft rejection during the same admission.

CONCLUSIONS

S. aureus represents an important cause of morbidity in pediatric SOT recipients. While the majority of infections occurred late after transplant (>6 months), those acquired in the early post-transplant period were more often invasive and caused by MSSA in our hospital. Physicians caring for SOT recipients should be aware of the risks posed by this pathogen and the potential concomitant morbidity including graft rejection.

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.

Multidrug-resistant bacterial infections after liver transplantation: An ever-growing challenge

Bacterial infections are a leading cause of morbidity and mortality among solid organ transplant recipients. Over the last two decades, various multidrug-resistant (MDR) pathogens have emerged as relevant causes of infection in this population. Although this fact reflects the spread of MDR pathogens in health care facilities worldwide, several factors relating to the care of transplant donor candidates and recipients render these patients particularly prone to the acquisition of MDR bacteria and increase the likelihood of MDR infectious outbreaks in transplant units. The awareness of this high vulnerability of transplant recipients to infection leads to the more frequent use of broad-spectrum empiric antibiotic therapy, which further contributes to the selection of drug resistance. This vicious cycle is difficult to avoid and leads to a scenario of increased complexity and narrowed therapeutic options. Infection by MDR pathogens is more frequently associated with a failure to start appropriate empiric antimicrobial therapy. The lack of appropriate treatment may contribute to the high mortality occurring in transplant recipients with MDR infections. Furthermore, high therapeutic failure rates have been observed in patients infected with extensively-resistant pathogens, such as carbapenem-resistant Enterobacteriaceae, for which optimal treatment remains undefined. In such a context, the careful implementation of preventive strategies is of utmost importance to minimize the negative impact that MDR infections may have on the outcome of liver transplant recipients. This article reviews the current literature regarding the incidence and outcome of MDR infections in liver transplant recipients, and summarizes current preventive and therapeutic recommendations.

Staphylococcus aureus - antimicrobial resistance and the immunocompromised child

Children with immunocompromising conditions represent a unique group for the acquisition of antimicrobial resistant infections due to their frequent encounters with the health care system, need for empiric antimicrobials, and immune dysfunction. These infections are further complicated in that there is a relative paucity of literature on the clinical features and management of Staphylococcus aureus infections in immunocompromised children. The available literature on the clinical features, antimicrobial susceptibility, and management of S. aureus infections in immunocompromised children is reviewed. S. aureus infections in children with human immunodeficiency virus (HIV) are associated with higher HIV viral loads and a greater degree of CD4 T-cell suppression. In addition, staphylococcal infections in children with HIV often exhibit a multidrug resistant phenotype. Children with cancer have a high rate of S. aureus bacteremia and associated complications. Increased tolerance to antiseptics among staphylococcal isolates from pediatric oncology patients is an emerging area of research. The incidence of S. aureus infections among pediatric solid organ transplant recipients varies considerably by the organ transplanted; in general however, staphylococci figure prominently among infections in the early posttransplant period. Staphylococcal infections are also prominent pathogens among children with a number of immunodeficiencies, notably chronic granulomatous disease. Significant gaps in knowledge exist regarding the epidemiology and management of S. aureus infection in these vulnerable children.

Retroperitoneal aspergilloma

We report a previously healthy 8-year-old boy who presented to the hospital with a palpable abdominal mass, fever and abdominal pain. CT and MRI scans confirmed a large mass that was centered in the retroperitoneum. The lesion was biopsied and the histology showed branching hyphae. Tissue cultures grew Aspergillus fumigatus and a diagnosis of aspergilloma was made. The immunological work-up did not reveal an immunodeficiency. This case is a unique presentation of aspergilloma presenting in an unusual location and in an immunocompetent patient.

Analysis of infections in the first 3-month after living donor liver transplantation

AIM: To identify factors related to serious postoperative bacterial and fungal infections in the first 3 mo after living donor liver transplantation (LDLT).

METHODS: In the present study, the data of 207 patients from 2004 to 2011 were reviewed. The pre-, intra- and post-operative factors were statistically analyzed. All transplantations were approved by the ethics committee of West China Hospital, Sichuan University. Patients with definitely preoperative infections and infections within 48 h after transplantation were excluded from current study. All potential risk factors were analyzed using univariate analyses. Factors significant at a P < 0.10 in the univariate analyses were involved in the multivariate analyses. The diagnostic accuracy of the identified risk factors was evaluated using receiver operating curve.

RESULTS: The serious bacterial and fungal infection rates were 14.01% and 4.35% respectively. Enterococcus faecium was the predominant bacterial pathogen, whereas Candida albicans was the most common fungal pathogen. Lung was the most common infection site for both bacterial and fungal infections. Recipient age older than 45 years, preoperative hyponatremia, intensive care unit stay longer than 9 d, postoperative bile leak and severe hyperglycemia were independent risk factors for postoperative bacterial infection. Massive red blood cells transfusion and postoperative bacterial infection may be related to postoperative fungal infection.

CONCLUSION: Predictive risk factors for bacterial and fungal infections were indentified in current study. Pre-, intra- and post-operative factors can cause postoperative bacterial and fungal infections after LDLT.

Risk factors for infection after liver transplantation

Infection is a common cause of morbidity and mortality after liver transplantation. Risk factors relate to transplantation factors, donor and recipient factors. Transplant factors include ischaemia-reperfusion damage, amount of intra-operative blood transfusion, level and type of immunosuppression, rejection, and complications, prolonged intensive care stay with dialysis or ventilation, type of biliary drainage, repeat operations, re-transplantation, antibiotics, antiviral regimen, and environment. Donor risk factors include infection, prolonged intensive care stay, quality of the donor liver (e.g. steatosis), and viral status. For the recipient the most important are MELD score >30, malnutrition, renal failure, acute liver failure, presence of infection or colonisation, and immune status for viruses like cytomegalovirus. In recent years it has become clear that genetic polymorphisms in innate immunity, especially the lectin pathway of complement activation and in Toll-like receptors importantly contribute to the infection risk after liver transplantation. Therefore, the risk for infections after liver transplantation is a multifactorial problem and all factors need attention to reduce this risk.