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

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.

Comparative Effectiveness of Perioperative Antibiotic Regimens to Prevent Surgical Site Infections in Pediatric Liver Transplant Recipients

BACKGROUND

Surgical site infections (SSIs) are a common complication in liver transplant (LT) recipients. Lack of pediatric prophylaxis guidelines results in variation in preventative antibiotic regimens.

METHODS

We performed a retrospective observational study of LT recipients <18 years old using a merged data set that included data from the Pediatric Health Information System and the United Network for Organ Sharing between 2006 and 2017. The exposure was defined as the antibiotic(s) received within 24 hours of LT, with 6 categories, ranging from narrow (category 1: cefazolin), to broad). The primary outcome was presence or absence of SSI in the index admission. Mixed-effects logistic regression compared the effectiveness of each category in preventing SSI, relative to category 1.

RESULTS

Of the 2586 LT, 284 (11%) met SSI criteria. The SSI rate was higher in the younger subcohort (16.2%) than in the older (8.6%), necessitating a stratified analysis. Antibiotics from category 5 were most commonly used. In the younger subcohort, the adjusted risk was increased in all categories compared with the reference, most notably in category 3 (odds ratio [OR], 2.58 [95% confidence interval: .69-9.59]) and category 6 (2.76 [.66-11.56]). In the older subcohort, estimated ORs were also increased for each category, most notably in category 4 (2.49 [95% confidence interval: .99-6.27]). None of the ORs suggested benefit from broader-spectrum prophylaxis. Our E-value assessment suggests that it's unlikely there is unmeasured confounding by indication to the degree necessary to revert ORs to protective.

CONCLUSIONS

There was wide variation in antibiotic prophylaxis. Adjusted analyses did not reveal a protective benefit of broader-spectrum prophylaxis in either subcohort, suggesting that narrower regimens may be adequate.

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.

Diminished measles immunity after paediatric liver transplantation-A retrospective, single-centre, cross-sectional analysis

Liver transplantation in childhood has an excellent long-term outcome, but is associated with a long-term risk of infection. Measles is a vaccine-preventable infection, with case series describing severe courses with graft rejection, mechanical ventilation and even death in liver transplant recipients. Since about 30% of liver transplanted children receive liver transplants in their first year of life, not all have reached the recommended age for live vaccinations. On the contrary, live vaccines are contraindicated after transplantation. In addition, vaccination response is poorer in individuals with liver disease compared to healthy children. This retrospective, single-centre, cross-sectional study examines measles immunity in paediatric liver transplant recipients before and after transplantation. Vaccination records of 239 patients, followed up at Hannover Medical School between January 2021 and December 2022 were analysed. Twenty eight children were excluded due to stem cell transplantation, regular immunoglobulin substitution or measles vaccination after transplantation. More than 55% of all 211 children analysed and 75% of all those vaccinated at least once are measles seropositive after transplantation-48% after one and 84% after two vaccinations-which is less than in healthy individuals. Interestingly, 26% of unvaccinated children also showed measles antibodies and about 5-15% of vaccinated patients who were seronegative at the time of transplantation were seropositive afterwards, both possibly through infection. In multivariable Cox proportional hazards regression, the number of vaccinations (HR 4.30 [95% CI 2.09-8.83], p<0.001), seropositivity before transplantation (HR 2.38 [95% CI 1.07-5.30], p = 0.034) and higher age at time of first vaccination (HR 11.5 [95% CI 6.92-19.1], p<0.001) are independently associated with measles immunity after transplantation. In contrast, older age at testing is inversely associated (HR 0.09 [95% CI 0.06-0.15], p<0.001), indicating a loss of immunity. Vaccination in the first year of life does not pose a risk of non-immunity. The underlying liver disease influences the level of measles titres of twice-vaccinated patients; those with acute liver failure being the lowest compared to children with metabolic disease. In summary, vaccine response is poorer in children with liver disease. Liver transplant candidates should be vaccinated before transplantation even if this is earlier in the first year of life. Checking measles IgG and re-vaccinating seronegative patients may help to achieve immunity after transplantation.

Update on Epidemiology and Outcomes of Infection in Pediatric Organ Transplant Recipients

Pediatric solid organ transplant (SOT) recipients are at risk for infection following transplantation. Data from adult SOT recipients are often used to guide prevention and treatment of infections associated with organ transplantation in children. This article highlights key recent pediatric SOT-specific publications for an array of infectious complications of organ transplantation. Attention is given to areas of need for future study.

Bacteremia in Pediatric Liver Transplant Recipients

BACKGROUND

We aimed to determine the frequency of bacteremia, septic shock and bacterial meningitis in pediatric liver transplant recipients (pLTRs) in the outpatient setting and to identify clinical factors associated with bacteremia.

METHODS

Multicenter retrospective study of pLTRs evaluated in the emergency department or outpatient clinic between 2010 and 2018 for suspected infection, defined as fever ≥38 °C or a blood culture obtained. We excluded patients with nontransplant immunodeficiency, multiorgan transplants or intestinal failure. The primary outcome was bacteremia; secondary outcomes included fluid-refractory septic shock, bacterial meningitis and antibiotic resistance. The unit of analysis was the encounter.

RESULTS

A total of 151 children had 336 encounters for infection evaluation within 2 years of transplant. Of 307 (91.4%) encounters with blood cultures, 17 (5.5%) had bacteremia, with 10 (58.8%) occurring within 3 months of transplant. Fluid-refractory septic shock and bacterial meningitis occurred in 7 out of 307 (2.8%) and 0 out of 307 encounters, respectively. Factors associated with bacteremia included closer proximity to transplant (<3 months) [odds ratio (OR): 3.6; 95% confidence interval (CI): 1.3-9.8; P = 0.01], shorter duration of illness (OR: 4.3; 95% CI: 1.5-12.0; P < 0.01) and the presence of a central venous catheter (CVC) (OR: 12.7; 95% CI: 4.4-36.6; P < 0.01). However, 5 (29.4%) encounters with bacteremia had none of these factors. Among Gram-positive pathogens, 1 out of 7 (14.2%) isolates were resistant to vancomycin. Among Gram-negative pathogens, 3 out of 13 (23.1%) isolates were resistant to 3rd generation cephalosporins.

CONCLUSIONS

Bacteremia was an important cause of infection within 2 years of pLTR. Clinical factors increased the risk of bacteremia. Further, large sample studies should derive multivariable models to identify those at high and low risk of bacteremia to optimize antibiotic use.

Intestinal Dominance by Multidrug-Resistant Bacteria in Pediatric Liver Transplant Patients

Pediatric liver transplantation (PLTx) is commonly associated with extensive antibiotic treatments that can produce gut microbiome alterations and open the way to dominance by multidrug-resistant organisms (MDROs). In this study, the relationship between intestinal Relative Loads (RLs) of β-lactamase genes, antibiotic consumption, microbiome disruption, and the extraintestinal dissemination of MDROs among PLTx patients is investigated. 28 PLTx patients were included, from whom 169 rectal swabs were collected. Total DNA was extracted and bla_{CTX-M-1-Family}, bla_OXA-1, bla_OXA-48, and bla_VIM were quantified via quantitative polymerase chain reaction (qPCR) and normalized to the total bacterial load (16SrRNA) through LogΔΔCt to determine the RLs. 16SrRNA sequencing was performed for 18 samples, and metagenomic sequencing was performed for 2. Patients' clinical data were retrieved from the hospital's database. At least one of the genes tested were detected in all of the patients. The RLs for bla_{CTX-M-1-Family}, bla_OXA-1, bla_OXA-48, and bla_VIM were higher than 1% of the total bacterial population in 67 (80.73%), 56 (78.87%), 57 (77.03%) and 39 (61.9%) samples, respectively. High RLs for bla_{CTX-M-1-Family}, bla_OXA-1, and/or bla_OXA-48, were positively associated with the consumption of carbapenems with trimethoprim-sulfamethoxazole and coincided with low diversity in the gut microbiome. Low RLs were associated with the consumption of noncarbapenem β-lactams with aminoglycosides (P < 0.05). Extraintestinal isolates harboring the same gene(s) as those detected intraintestinally were found in 18 samples, and the RLs of the respective swabs were high. We demonstrated a relationship between the consumption of carbapenems with trimethoprim-sulfamethoxazole, intestinal dominance by MDROs and extraintestinal spread of these organisms among PLTx patients. IMPORTANCE In this study, we track the relative intestinal loads of antibiotic resistance genes among pediatric liver transplant patients and determine the relationship between this load, antibiotic consumption, and infections caused by antibiotic-resistant organisms. We demonstrate that the consumption of broad spectrum antibiotics increase this load and decrease the gut microbial diversity among these patients. Moreover, the high loads of resistance genes were related to the extraintestinal spread of multidrug-resistant organisms. Together, our data show that the tracking of the relative intestinal loads of antibiotic resistance genes can be used as a biomarker that has the potential to stop the extraintestinal spread of antibiotic-resistant bacteria via the measurement of the intestinal dominance of these organisms, thereby allowing for the application of preventive measures.

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.

Incidence, Clinicomicrobiological Characteristics, Risk Factors, and Treatment ‎Outcomes of Bacterial Infections Following Liver Transplantation in Pediatrics: A ‎Retrospective Cohort Study

Background: Liver transplantation (LT) is the definitive treatment for patients with advanced liver failure. Bacterial infections are common consequences of organ transplantation resulting from immune suppression and prolonged hospitalization. Methods: This retrospective cohort study examined the records of all liver transplant pediatrics under 18 years of age in Abu-Ali Sina hospital, Shiraz, Fars province, Iran, from April 2019 to February 2020. Demographic, laboratory, and clinical data were extracted along with the administered therapeutic approach for the patient. Results: Of 80 enrolled patients, 52 were male, and 28 were female, with a median age of 60 months. An incidence of 67.9% of bacterial infections was recorded. Gram-negative and Gram-positive pathogens accounted for 64.06% and 35.93% of infections, respectively. Surgical site infections were the most common ones. The length of ICU stay, hospitalization, mechanical ventilation duration, and re-hospitalization were significantly higher in the infected group than in non-infected pediatrics (P-value < 0.05). Multivariate regression analysis showed that the only risk factor for bacterial infections after LT was the length of ICU stay. The mortality rate was 22%, which was significantly higher among the infection group (P = 0.008). Conclusions: A high rate of bacterial infections and an increasing prevalence of nosocomial and antibiotic-resistant pathogens were detected in the early period after LT.

Epidemiology, Risk Factors and Outcome Due to Multidrug Resistant Organisms in Paediatric Liver Transplant Patients in the Era of Antimicrobial Stewardship and Screening

(1) Background: Multidrug-resistant organisms (MDRO) are a growing problem in liver transplant recipients (LTR), associated with high morbidity and mortality. We reviewed the impact of antimicrobial stewardship (AMS) and active screening of MDRO on the epidemiology and outcomes in paediatric LTR. (2) Methods: Single-centre retrospective review of paediatric LTR from January 2017 to December 2018. (3) Results: Ninety-six children were included; 32 (33%) patients were colonised with ≥1 MDRO and 22 (23%) patients had MDRO infections. Median (IQR) duration for start of infection was 9.5 (1.8−16.0) days. Colonisation rate with Gram-positive MDRO was 15.6%, with infection rate of 6.2%; majority due to Vancomycin-Resistant Enterococcus faecium (VRE). Colonisation with Gram-negative MDRO was 27.0%, with infection rate of 16.6%; majority due to extended-spectrum β-lactamase producing Enterobacteriaceae. Colonisation and infection rate due to Carbapenem-resistant Enterobacteriaceae was 6% and 3%, respectively, during screening and AMS, compared to historical control of 25% and 30%, respectively, without screening and AMS. There was significant reduction in VRE and CRE infection during AMS period in comparison to historical control. Pre-transplant risk factors including bacterial infections pre-transplant (p < 0.01), diagnosis of biliary atresia (p = 0.03), exposure to antibiotics (p < 0.01), EBV viraemia (p = 0.01), and auxiliary transplantation (p < 0.01) were associated with post-transplant MDRO infections. Patients with MDRO infections had longer length of hospital and paediatric intensive care unit stay days (p < 0.01) but associated with no mortality. (4) Conclusions: Our results demonstrate low incidence of colonisation and infections with MDRO, which were associated with high morbidity but no mortality in paediatric LTR. There was significant reduction in MRSA, VRE, and CRE during AMS period compared to pre-AMS era. Some risk factors are unavoidable but antibiotic overuse, early initiation of appropriate antibiotic therapy and effective infection prevention strategies can be monitored with multifaceted approach of AMS and screening of MDRO. With limited therapeutic options for MDRO and efficacy data of newer antibiotics in paediatric LTR, robust infection control practices are of paramount importance.

Surgical Antimicrobial Prophylaxis in Abdominal Surgery for Neonates and Paediatrics: A RAND/UCLA Appropriateness Method Consensus Study

Surgical site infections (SSIs), i.e., surgery-related infections that occur within 30 days after surgery without an implant and within one year if an implant is placed, complicate surgical procedures in up to 10% of cases, but an underestimation of the data is possible since about 50% of SSIs occur after the hospital discharge. Gastrointestinal surgical procedures are among the surgical procedures with the highest risk of SSIs, especially when colon surgery is considered. Data that were collected from children seem to indicate that the risk of SSIs can be higher than in adults. This consensus document describes the use of preoperative antibiotic prophylaxis in neonates and children that are undergoing abdominal surgery and has the purpose of providing guidance to healthcare professionals who take care of children to avoid unnecessary and dangerous use of antibiotics in these patients. The following surgical procedures were analyzed: (1) gastrointestinal endoscopy; (2) abdominal surgery with a laparoscopic or laparotomy approach; (3) small bowel surgery; (4) appendectomy; (5) abdominal wall defect correction interventions; (6) ileo-colic perforation; (7) colorectal procedures; (8) biliary tract procedures; and (9) surgery on the liver or pancreas. Thanks to the multidisciplinary contribution of experts belonging to the most important Italian scientific societies that take care of neonates and children, this document presents an invaluable reference tool for perioperative antibiotic prophylaxis in the paediatric and neonatal populations.

Under-Vaccination in Pediatric Liver Transplant Candidates with Acute and Chronic Liver Disease—A Retrospective Observational Study of the European Reference Network TransplantChild

Infection is a serious concern in the short and long term after pediatric liver transplantation. Vaccination represents an easy and cheap opportunity to reduce morbidity and mortality due to vaccine-preventable infection. This retrospective, observational, multi-center study examines the immunization status in pediatric liver transplant candidates at the time of transplantation and compares it to a control group of children with acute liver disease. Findings show only 80% were vaccinated age-appropriately, defined as having received the recommended number of vaccination doses for their age prior to transplantation; for DTP-PV-Hib, less than 75% for Hepatitis B and two-thirds for pneumococcal conjugate vaccine in children with chronic liver disease. Vaccination coverage for live vaccines is better compared to the acute control group with 81% versus 62% for measles, mumps and rubella (p = 0.003) and 65% versus 55% for varicella (p = 0.171). Nevertheless, a country-specific comparison with national reference data suggests a lower vaccination coverage in children with chronic liver disease. Our study reveals an under-vaccination in this high-risk group prior to transplantation and underlines the need to improve vaccination.

Bacterial and fungal bloodstream infections in pediatric liver and kidney transplant recipients

Background

Bacterial and fungal bloodstream infections (BSI) are common after pediatric liver and kidney transplantations and associated with morbidity and mortality. However, knowledge about incidence rates, pathogen composition, and resistance patterns is limited. We aimed to describe the pattern of bacterial and fungal BSI in a cohort of pediatric liver and kidney transplant recipients.

Methods

A prospective study of 85 pediatric liver and kidney transplant recipients transplanted from 2010 to 2017 with a total of 390 person-years of follow-up. Clinical characteristics and BSI were retrieved from national registries assuring nationwide follow-up for at least 1 year. BSI incidence rates and pathogen composition were investigated and stratified by the time post-transplantation and type of transplanted organ.

Results

A total of 29 BSI were observed within the first 5 years post-transplantation with 16 different pathogens. The overall incidence rate of first BSI was 1.91 per 100 recipients per month (95% CI, 1.1–3.1) in the first year post-transplantation. The most common pathogens were Enterococcus faecium, Candida albicans, Escherichia coli, and Klebsiella pneumoniae. The pathogen composition depended on the transplanted organ with a higher proportion of BSI with Enterobacterales in kidney transplant recipients than in liver transplant recipients (67% vs. 20%, p = 0.03), while multiple pathogens were detected in the liver transplant recipients.

Conclusions

BSI were common in pediatric liver and kidney transplant recipients and the pathogen composition differed between liver and kidney transplant recipients. Guidelines for empiric antibiotic therapy should consider the type of transplanted organ as well as the local resistance patterns.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06224-2.

High prevalence of multidrug-resistant gram-negative bacterial infection following pediatric liver transplantation

Bacterial infection has been identified as one of the most significant complications of liver transplantation (LT). Multidrug-resistant (MDR) gram-negative bacteria (GNB) infection remains problematic issue following LT in the adults. However, data in children are scarce. We aimed to examine the prevalence and associated factors of MDR-GNB infection among pediatric LT recipients.We performed a single-center retrospectively study of 118 children who underwent LT between January 2010 and December 2018. Data on the prevalence, clinical characteristics, types, and sites of MDR-GNB infection within 3 months after LT as well as the treatment outcomes were collected. Multidrug resistance was defined as acquired non-susceptibility to at least 1 agent in 3 or more antibiotic classes.In total, 64 (53.7%) patients developed 96 episodes of culture-proven bacterial infection with 93 GNB isolates. Moreover, there were 58 (62.4%) MDR-GNB isolates, with a predominance of Klebsiella pneumoniae (32.7%), Escherichia coli (31%), and Pseudomonas aeruginosa (10.3%). Interestingly, 10 (17.2%) isolates were determined to be carbapenem-resistant Enterobacteriaceae. The median time to MDR-GNB infection was 9 (interquartile range: 5-33) days. The most common type of infection was intra-abdominal infection (47.9%). In the multivariate analysis, the significant variables associated with post-LT MDR-GNB infection include exposure to third-generation cephalosporins (hazard ratio [HR]: 2.16, P = .023), operative time (hazard ratio [HR] 1.20, P = .009), and length of intensive care unit stay (HR 1.03, P = .049). With a focus on carbapenem-resistant Enterobacteriaceae infection, a pediatric end-stage liver disease score >21 was the only significant 6 variable in the multivariate analysis (HR 11.48, P = .024). The overall 3-month mortality rate was 6.8%.This study has highlighted the high prevalence rate of MDR-GNB infection after pediatric LT. Therefore, caution on the emergence of MDR-GNB infection should be paid in at-risk children. Moreover, knowledge regarding the prevalence of MDR-GNB infection and resistant patterns is essential for guideline development to prevent and minimize the risk of MDR-GNB infection in this group of patients.