Infections after liver transplantation. An analysis of 101 consecutive cases

High Number of Plasma Exchanges Increases the Risk of Bacterial Infection in ABO-incompatible Living Donor Liver Transplantation

BACKGROUND

Bacterial infections are major complications that cause significant mortality and morbidity in living donor liver transplantation (LDLT). The risk of bacterial infection has not been studied in ABO-incompatible (ABOi) recipients with a desensitization protocol in relation to the number of plasma exchanges (PEs). Therefore, we aimed to analyze the risk of bacterial infection in ABOi LDLT recipients with a high number of PEs compared with recipients with a low number of PEs.

METHODS

A retrospective study was performed with 681 adult LDLT recipients, of whom 171 ABOi LDLT recipients were categorized into the high (n = 52) or low (n = 119) PE groups based on a cutoff value of 6 PE sessions. We compared bacterial infections and postoperative bacteremia within 6 mo after liver transplantation with the ABO-compatible (ABOc) LDLT group (n = 510) as a control group.

RESULTS

The high PE group showed a bacterial infection rate of 49.9% and a postoperative bacteremia rate of 28.8%, which were significantly higher than those of the low PE group (31.1%, 17.8%) and the ABOc group (26.7%, 18.0%). In multivariate analysis, the high PE group was found to have a 2.4-fold higher risk of bacterial infection ( P  = 0.008). This group presented a lower 5-y survival rate of 58.6% compared with the other 2 groups (81.5% and 78.5%; P  = 0.030 and 0.001).

CONCLUSIONS

A high number of preoperative PEs increases bacterial infection rate and postoperative bacteremia in ABOi LDLT.

Epidemiology and Prevention of Early Infections by Multi-Drug-Resistant Organisms in Adults Undergoing Liver Transplant: A Narrative Review

Invasive bacterial infections are a leading cause of morbidity and mortality after liver transplant (LT), especially during the first months after LT, and infections due to multi-drug-resistant organisms (MDRO) are increasing in this setting. Most of the infections in patients in intensive care unit arise from the endogenous microflora and, for this reason, pre-LT MDRO rectal colonization is a risk factor for developing MDRO infections in the post-LT. Moreover, the transplanted liver may carry an increased risk of MDRO infections due to organ transportation and preservation, to donor intensive care unit stay and previous antibiotic exposure. To date, little evidence is available about how MDRO pre-LT colonization in donors and recipients should address LT preventive and antibiotic prophylactic strategies, in order to reduce MDRO infections in the post-LT period. The present review provided an extensive overview of the recent literature on these topics, with the aim to offer a comprehensive insight about the epidemiology of MDRO colonization and infections in adult LT recipients, donor-derived MDRO infections, possible surveillance, and prophylactic strategies to reduce post-LT MDRO infections.

The prevalence of latent/chronic infection in liver transplant candidates in Taleghani Hospital of Tehran, Iran, from 2020 until 2021

Aim

The present study aimed to study the prevalence of various latent infections in pre-transplanted patients.

Background

Due to chronic immunosuppressive therapy, patients receiving organ transplants are at risk for reactivation of various infections. Due to the complications in the course of diagnosing and treating the post-transplant infection, screening transplant recipients and donors is vital.

Methods

This retrospective cohort study was performed between March 2020 and 2021. A total of 193 patients receiving a liver transplant in Taleghani Hospital, Tehran, Iran were enrolled.

Results

One-hundred and three (53.4%) patients were men, with an average age of 48.4 ± 13.3 years. Among viruses, 177 (91.7%) patients had a positive IgG titer for CMV. Anti-EBV IgG was positive in 169 (87.6%) patients. One-hundred and seventy-five (90.7%) patients had a positive IgG titer for the VZV. One-hundred and sixty-six (86.0%) cases had positive IgG anti-HSV antibodies. According to our findings, none of the patients were infected with HIV, but 9 (4.7%) cases and 141 (73.1%) had positive anti-HCV and anti-HAV IgG antibodies, respectively. HBV surface (HBs) antigen was also reported positive in 17 (8.8%) patients, while the HBs antibody was positive in 29 (15.0%) patients.

Conclusion

In our study, most of the patients had positive serology for latent viral infections such as CMV, EBV, VZV, and HSV, but the prevalence of latent tuberculosis and viral hepatitis was low among transplant candidates.

Four Decades of Clinical Liver Transplantation Research: Results of a Comprehensive Bibliometric Analysis

BACKGROUND

Nearly 40 y have passed since the 1983 National Institutes of Health Consensus-Development-Conference, which has turned liver transplantation (LT) from a clinical experiment into a routine therapeutic modality. Since' clinical LT has changed substantially. We aimed to comprehensively analyze the publication trends in the most-cited top-notch literature in LT science over a 4-decade period.

METHODS

A total of 106 523 items were identified between January 1981 and May 2021 from the Web of Science Core Collection. The top 100 articles published were selected using 2 distinct citation-based strategies to minimize bias. Various bibliometric tools were used for data synthesis and visualization.

RESULTS

The citation count for the final dataset of the top 100 articles ranged from 251 to 4721. Most articles were published by US authors (n = 61). The most prolific institution was the University of Pittsburgh (n = 15). The highest number of articles was published in Annals of Surgery, Hepatology, and Transplantation ; however, Hepatology publications resulted in the highest cumulative citation of 9668. Only 10% of the articles were classified as evidence level 1. Over 90% of first/last authors were male. Our data depict the evolution of research focus over 40 y. In part, a disproportional flow of citations was observed toward already well-cited articles. This might also project a slowed canonical progress, which was described in other fields of science.

CONCLUSIONS

This study highlights key trends based on a large dataset of the most-cited articles over a 4-decade period. The present analysis not only provides an important cross-sectional and forward-looking guidance to clinicians, funding bodies, and researchers but also draws attention to important socio-academic or demographic aspects in LT.

A Prospective Review of Preoperative Nutritional Status and Its Influence on the Outcome of Abdominal Surgery

Aim

To assess the incidence of malnutrition in a surgical gastroenterology unit and analyze its impact on postoperative complication rates.

Method

Data were prospectively accrued from patients admitted for emergency or elective surgery to the gastrointestinal surgery unit at Jaslok Hospital between May 2013 and May 2014. The nutritional status was preoperatively assessed by using anthropometric parameters like body mass index (BMI), midarm circumference (MAC), and tissue skinfold thickness (TSFT). In addition, a subjective global assessment scale (SGA), serum albumin, and absolute lymphocyte count (ALC) were used. Patients with BMI <18.5, MAC <24 cm in males and <22 cm in females, and TSFT <10 mm were considered malnourished. Patients with serum albumin between 3 and 3.5 g/dl were considered mild, 2.4-2.9 g/dl was moderate, and <2.4 g/dl were severely malnourished. Patients with ALC between 1200 and 2000/cm were labelled mild, between 800 and 1199/cm were moderate, and <800/cm were severely malnourished. As per SGA, well-nourished had less than 5% weight loss or if more than 5%, with recent gain and improved appetite, mild/moderately malnourished had 5% to 10% weight loss with no gain, mild subcutaneous fat loss, and those severely malnourished had more than 10% weight loss, severe subcutaneous fat loss, and muscle wasting. Postoperative complications were graded as per the Clavien-Dindo classification. Patients with grades 1 and 2 complications were labelled as minor and the rest as major.

Result

Men in the age group of 40-60 years comprised the majority of the study population. The most frequent reason for admission was cholelithiasis. The overall incidence of malnutrition was 22.16%. Out of the 96 patients who had complications, 45 had minor and 41 had significant complications. Amongst the well-nourished, the incidence of complications was 26.62% of which the majority were minor complications. Severely malnourished patients had a high complication rate (63.38%); 32% out of the 63.38% developed significant complications. The majority of the patients suffering from severe malnutrition belonged to the sub-group with chronic pancreatitis and carcinoma of the pancreas. According to the chi-square analysis of the data, ALC, serum albumin, and SGA correlate with the postoperative complication rate with a p-value <0.05 as significant. On the contrary, BMI, MAC, and TSFT did not correlate with postoperative complications.

Conclusion

Preoperative malnutrition is common among patients undergoing abdominal surgeries in the urban private health care sector. Although there have been studies that have analyzed the incidence of malnutrition in patients undergoing oncological surgeries, there is limited literature on malnutrition among patients subjected to gastrointestinal surgeries. We conclude that simple bedside nutritional assessment tools like serum albumin, absolute lymphocyte count, and SGA can accurately identify malnourished patients preoperatively and are good predictors of postoperative complications. Hence, it is imperative to assess and attempt to improve the nutritional status of the patients preoperatively.

Invasive Fungal Infections After Liver Transplantation: A Retrospective Matched Controlled Risk Analysis

Background

Invasive fungal infections (IFI) are major risks for mortality after liver transplantation (LT). The aim of this study was to evaluate possible risk factors for the development of IFI after LT.

Material/Methods

All adult patients with IFI after LT between January 2012 and December 2016 at Essen University were identified. Pre-, intra-, and postoperative data were reviewed. These were compared to a 1-to-3 matched control group. Multinominal univariate and multivariate regression analyses were performed.

Results

Out of the 579 adults who underwent LT, 33 (5.6%) developed postoperative IFI. Fourteen had invasive aspergillosis with 7 (50%) mortality, and 19 had Candida sepsis with 7 (37%) mortality. The overall mortality due to invasive fungal infections was 42%. Perfusion fluid contamination with yeast was detected in 5 patients (15%). Multivariate regression analyses showed that preoperative dialysis (OR=1.163; CI: 1.038–1.302), Eurotransplant donor risk index (OR=0.04; CI=0.003–0.519), length of hospital stay (OR=25.074; CI: 23.99–26.208), and yeast contamination of the preservation fluid (OR=47.8; CI: 4.77–478, 96) were associated with IFI in the Candida group, whereas duration of surgery (OR=1.013; CI: 1.005–1.022), ventilation hours (OR=0.993; CI=0.986–0.999), and days of postoperative dialysis (OR=1.195; CI: 1.048–1,362) were associated with IFI in the aspergillosis group.

Conclusions

Post-LT IFI had 42% mortality in our cohort. Prophylactic antifungal therapy should be expanded to broader risk groups as defined above.

Oral diseases after liver transplantation: a systematic review and meta-analysis

Objective To conduct a systematic review and meta-analysis to evaluate the impact of liver transplantation on the occurrence and frequency of oral diseases in humans.Data sources The study query was performed on Medline/PubMed, Ovid, Cochrane Library and Embase databases, including the grey literature.Data selection Observational studies comparing the frequency of oral manifestations in post-liver transplantation patients versus reference population were eligible for inclusion.Data extraction and analysis The article selection, data extraction and quality assessment were executed by three independent investigators. A random-effects meta-analysis was carried out for computation of relative risks of oral malignancies (standardised incidence ratio [SIR] and 95% confidence interval [CI]).Data synthesis Among 248 studies identified, 11 met the eligibility criteria and six were included in the meta-analysis. Opportunistic fungal infections (Candida spp.) and lesions with malignant potential were reported to be more frequently prevalent after liver transplantation. Calculations indicated that after liver transplantation, the patients have a fivefold increased risk for oral cancer occurrence compared to the general population (SIR = 5.006; 95% CI 2.803 to 8.94; p <0.001).Conclusions The findings suggest that liver transplantation increases the risk of oral malignancies and the frequency of other mucosal lesions.

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.

Risk factor for lung infection in recipients after liver transplantation: A meta-analysis

Lung infection (LI) often occurs in patients with liver transplantation (LT). This meta-analysis was conducted to determine the risk factors associated with LI after LT. We retrieved relevant research published as of February 2020 from eight electronic databases. The studies were reviewed against the inclusion and exclusion criteria. The Z test was used to determine the combined odds ratio (OR) or the standardized mean difference (SMD) of the risk factors. We used the OR and its corresponding 95% confidence interval (CI) or the SMD and its corresponding 95% CI to identify significant differences in risk factors. A total of nine studies were included, comprising a total of 1624 recipients. Six risk factors associated with LI were identified after LT: Model for end-stage liver disease score (MELD score) (SMD = 0.40), Child-Pugh class C (OR = 3.00), intensive care unit (ICU) hospital stay (SMD = 1.35), mechanical ventilation (SMD = 1.03), bilirubin (SMD = 0.39), and atelectasis (OR = 7.28). Although certain risk factors have been identified as important factors for LI after LT, which may provide a basis for clinical prevention, a well-designed prospective study should be conducted to validate the findings of this study.

Is Routine Prophylaxis Against Pneumocystis jirovecii Needed in Liver Transplantation? A Retrospective Single-Centre Experience and Current Prophylaxis Strategies in Spain

In liver transplant (LT) recipients, Pneumocystis jirovecii pneumonia (PJP) is most frequently reported before 1992 when immunosuppressive regimens were more intense. It is uncertain whether universal PJP prophylaxis is still applicable in the contemporary LT setting. We aimed to examine the incidence of PJP in LT recipients followed at our institution where routine prophylaxis has never been practiced and to define the prophylaxis strategies currently employed among LT units in Spain. All LT performed from 1990 to October 2019 were retrospectively reviewed and Spanish LT units were queried via email to specify their current prophylaxis strategy. During the study period, 662 LT procedures were carried out on 610 patients. Five cases of PJP were identified, with only one occurring within the first 6 months. The cumulative incidence and incidence rate were 0.82% and 0.99 cases per 1000 person transplant years. All LT units responded, the majority of which provide prophylaxis (80%). Duration of prophylaxis, however, varied significantly. The low incidence of PJP in our unprophylaxed cohort, with most cases occurring beyond the usual recommended period of prophylaxis, questions a one-size-fits-all approach to PJP prophylaxis. A significant heterogeneity in prophylaxis strategies exists among Spanish LT centres.

Risk Factors for Acquisition of Carbapenem-Resistant Klebsiella pneumoniae and Mortality Among Abdominal Solid Organ Transplant Recipients with K. pneumoniae Infections

Background

For abdominal solid organ transplant (ASOT) recipients, infection with Klebsiella pneumoniae, particularly carbapenem-resistant K. pneumoniae (CRKP), can be life-threatening. The aims of this study were to characterize the risk factors associated with acquisition of CRKP and 90-day crude mortality among patients.

Material/Methods

In our cohort study, we retrospectively reviewed 68 K. pneumoniae-infected transplant recipients, studied their demographics, clinical manifestations, microbiology, and outcomes, and determined the risk factors associated with the occurrence of CRKP and crude mortality due to K. pneumoniae infections.

Results

Sixty-eight ASOT recipients (5.4%) experienced 78 episodes of K. pneumoniae infection. Among these, 20 patients (29.4%) died. The independent risk factors associated with mortality were multiple infected organs or sites (odds ratio=22.034, 95% confidence intervals=4.348–111.653, P=0.001) and septic shock (odds ratio=27.090, 95% confidence intervals=1.841–398.512, P=0.016). Risk factors associated with acquisition of CRKP were multiple infected organs or sites (odds ratio=3.056, 95% confidence intervals=1.091–8.556, P=0.033).

Conclusions

K. pneumoniae infections, especially CRKP, frequently occurred among ASOT recipients, with a high mortality rate. Multiple infected organs or sites and septic shock were predictors of crude mortality caused by K. pneumoniae infections, while CRKP infections were associated with multiple infected organs or sites. Greater efforts are needed towards improved antibiotic administration, early diagnosis and precise treatment, recognition of septic shock, and reduced length of hospitalization.

Infection within 2 weeks before liver transplantation closely related to prognosis of posttransplant infection: A single-center retrospective observational study in China

BACKGROUND

Infections still represent the main factors influencing morbidity and mortality following liver transplantation. This study aimed to evaluate the incidence and risk factors for infection and survival after liver transplantation.

METHODS

We retrospectively examined medical records in 210 liver recipients who underwent liver transplantation between April 2015 and October 2017 in our hospital. Clinical manifestations and results of pathogen detection test were used to define infection. We analyzed the prevalence, risk factors and prognosis of patients with infection.

RESULTS

The median follow-up was 214 days; the incidence of infection after liver transplantation was 46.7% (n = 98) which included pneumonia (43.4%), biliary tract infection (21.9%), peritonitis (21.4%) and bloodstream infection (7.6%). Among the pathogens in pneumonia, the most frequently isolated was Acinetobacter baumanii (23.5%) and Klebsiella pneumoniae (21.2%). Model for end-stage liver disease (MELD) score (OR = 1.083, 95% CI: 1.045-1.123; P < 0.001), biliary complication (OR = 4.725, 95% CI: 1.119-19.947; P = 0.035) and duration of drainage tube (OR = 1.040, 95% CI: 1.007-1.074; P = 0.017) were independent risk factors for posttransplant infection. All-cause mortality was 11.0% (n = 23). The prognostic factors for postoperative infection in liver recipients were prior-transplant infection, especially pneumonia within 2 weeks before transplantation. Kaplan-Meier curves of survival showed that recipients within 2 weeks prior infection had a significantly lower cumulative survival rate compared with those without infection (65.2% vs. 90.0%; hazard ratio: 4.480; P < 0.001).

CONCLUSIONS

Infection, especially pneumonia within 2 weeks before transplantation, complication with impaired renal function and MELD score after 7 days of transplantation was an independent prognostic factor for postoperative infection in liver transplant recipients.

Post liver transplant recurrent and de novo viral infections

Survival following liver transplantation has changed dramatically owing to improvement in surgical techniques, peri-operative care and optimal immunosuppressive therapy. Post-Liver transplant (LT) de novo or recurrent viral infection continues to cause major allograft dysfunction, leading to poor graft and patient survival in untreated patients. Availability of highly effective antiviral drugs has significantly improved post-LT survival. Patients transplanted for chronic hepatitis B infection should receive life-long nucleos(t)ide analogues, with or without HBIg for effective viral control. Patients with chronic hepatitis C should be commenced on directly acting antiviral (DAA) drugs prior to transplantation. DAA therapy for post-LT recurrent hepatitis C infection is associated with close to 100% sustained virological response (SVR), irrespective of genotype. De novo chronic Hepatitis E infection is an increasingly recognised cause of allograft dysfunction in LT recipients. Untreated chronic HEV infection of the graft may lead to liver fibrosis and allograft failure. CMV and EBV can reactivate leading to systemic illness following liver transplantation. With COVID-19 pandemic, post-transplant patients are at risk of SARS-Co-V2 infection. Majority of the LT recipients require hospitalization, and the mortality in this population is around 20%. Early recognition of allograft dysfunction and identification of viral aetiology is essential in the management of post-LT de novo or recurrent infections. Optimising immunosuppression is an important step in reducing the severity of allograft damage in the treatment of post-transplant viral infections. Viral clearance or control can be achieved by early initiation of high potency antiviral therapy.

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

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

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.

Pre- and post-transplant bacterial infections in liver transplant recipients

BACKGROUND

Early (<1 month) bacterial infection after liver transplant is a major cause of morbidity and mortality among liver transplant recipients. We investigated the impact of pre-transplant bacterial infection on early post-transplant bacterial infection incidence and outcomes.

METHODS

A retrospective cohort study identified all patients who underwent liver transplantation between January 1, 2011, and December 31, 2012, at a single tertiary center in the United States. Infections occurring within the 30 days prior to transplant and within the 30 following transplant were identified. Information regarding pre-transplant morbidity and post-transplant outcomes was collected.

RESULTS

One-hundred seventy-four patients were included in the study. Forty patients (23%) experienced a total of 50 pre-transplant infections. Fifty-two (30%) developed a total of 62 post-transplant infections. Patients with a pre-transplant infection were more likely to develop a post-transplant infection compared to patients without a pre-transplant infection (48% [19 of 40] vs. 25% [33 of 134], respectively, P = .006). Patients with a pre-transplant infection had a longer mean post-transplant length of stay compared to those without a pre-transplant infection (16.3 days vs. 10.4 days, respectively, P < .001), but survival at 30 days was similar in both groups (95% [38 of 40] vs. 97% [130 of 134, respectively, P = .56).

CONCLUSIONS

Among liver transplant recipients, pre-transplant infection is an important risk factor for early post-transplant bacterial infections. Pre-transplant infection is associated with increased early morbidity but not mortality after transplant.

The Causes and Outcomes of Early Relaparotomy Following Pediatric Living Donor Liver Transplantation

Early relaparotomy of adult recipients after living donor liver transplantation (LDLT) is significantly associated with poor prognosis. However, there are few reports focusing on pediatric recipients after LDLT. The aim of this study is to clarify the causes and outcomes of early relaparotomy after pediatric LDLT. A total of 265 pediatric recipients (272 LDLTs) transplanted from May 2001 to October 2015 were retrospectively analyzed. Early relaparotomy was defined as surgical intervention performed within 3 months after LDLT. Early relaparotomy was performed 49 times for 33 recipients (12.5%). The recipient and graft survival rates in the early relaparotomy group were significantly lower than those in the nonearly relaparotomy group, respectively (75.0% and 63.6% versus 96.6% and 95.8%; both P < 0.001). Left lateral segment grafts were used significantly more frequently in the nonrelaparotomy group (P = 0.01). According to the multivariate analysis, the preoperative Pediatric End-Stage Liver Disease (PELD)/Model for End-Stage Liver Disease (MELD) score of the early relaparotomy group was significantly higher than that of the nonearly relaparotomy group (13.7 versus 6.3; P = 0.04). According to the receiver operating characteristic curve, the preoperative PELD/MELD score cutoff point was 17.2. Early relaparotomy due to infectious causes led to significantly poorer graft survival than that due to noninfectious causes (P = 0.04). In conclusion, the recipient and graft survival rates of the early relaparotomy group were significantly lower than those of the nonearly relaparotomy group. A high preoperative PELD/MELD score was a risk factor for early relaparotomy. In particular, early relaparotomy due to infection showed a poor prognosis.

Intra-abdominal infections in solid organ transplant recipients: Guidelines from the American Society of Transplantation Infectious Diseases Community of Practice

This new guideline from the AST IDCOP reviews intra-abdominal infections (IAIs), which cause substantial morbidity and mortality among abdominal SOT recipients. Each transplant type carries unique risks for IAI, though peritonitis occurs in all abdominal transplant recipients. Biliary infections, bilomas, and intra-abdominal and intrahepatic abscesses are common after liver transplantation and are associated with the type of biliary anastomosis, the presence of vascular thrombosis or ischemia, and biliary leaks or strictures. IAIs after kidney transplantation include renal and perinephric abscesses and graft-site candidiasis, which is uncommon but may require allograft nephrectomy. Among pancreas transplant recipients, duodenal anastomotic leaks can have catastrophic consequences, and polymicrobial abscesses can lead to graft loss and death. Intestinal transplant recipients are at the highest risk for sepsis, infection due to multidrug-resistant organisms, and death from IAI, as the transplanted intestine is a contaminated, highly immunological, pathogen-rich organ. Source control and antibiotics are the cornerstone of the management of IAIs. Empiric antimicrobial regimens should be tailored to local susceptibility patterns and pathogens with which the patient is known to be colonized, with subsequent optimization once the results of cultures are reported.

Clinical and economic burden of infections in hospitalized solid organ transplant recipients compared with the general population in Canada - a retrospective cohort study

Infections continue to be a major cause of post-transplant morbidity and mortality, requiring increased health services utilization. Estimates on the magnitude of this impact are relatively unknown. Using national administrative databases, we compared mortality, acute care health services utilization, and costs in solid organ transplant (SOT) recipients to nontransplant patients using a retrospective cohort of hospitalizations in Canada (excluding Manitoba/Quebec) between April-2009 and March-2014, with a diagnosis of pneumonia, urinary tract infection (UTI), or sepsis. Costs were analyzed using multivariable linear regression. We examined 816 324 admissions in total: 408 352 pneumonia; 328 066 UTI's; and 128 275 sepsis. Unadjusted mean costs were greater in SOT compared to non-SOT patients with pneumonia [(C$14 923 ± C$29 147) vs. (C$11 274 ± C$18 284)] and sepsis [(C$23 434 ± C$39 685) vs. (C$20 849 ± C$36 257)]. Mortality (7.6% vs. 12.5%; P < 0.001), long-term care transfer (5.3% vs. 16.5%; P < 0.001), and mean length of stay (11.0 ± 17.7 days vs. 13.1 ± 24.9 days; P < 0.001) were lower in SOT. More SOT patients could be discharged home (63.2% vs. 44.3%; P < 0.001), but required more specialized care (23.5% vs. 16.1%; P < 0.001). Adjusting for age and comorbidities, hospitalization costs for SOT patients were 10% (95% CI: 8-12%) lower compared to non-SOT patients. Increased absolute hospitalization costs for these infections are tempered by lower adjusted costs and favorable clinical outcomes.

Surgical site infections: Guidelines from the American Society of Transplantation Infectious Diseases Community of Practice

These guidelines from the Infectious Diseases Community of Practice of the American Society of Transplantation review the diagnosis, prevention, and management of post-operative surgical site infections (SSIs) in solid organ transplantation. SSIs are a significant cause of morbidity and mortality in SOT recipients. Depending on the organ transplanted, SSIs occur in 3%-53% of patients, with the highest rates observed in small bowel/multivisceral, liver, and pancreas transplant recipients. These infections are classified by increasing invasiveness as superficial incisional, deep incisional, or organ/space SSIs. The spectrum of organisms implicated in SSIs in SOT recipients is more diverse than the general population due to other important factors such as the underlying end-stage organ failure, immunosuppression, prolonged hospitalizations, organ transportation/preservation, and previous exposures to antibiotics in donors and recipients that could predispose to infections with multidrug-resistant organisms. In this guideline, we describe the epidemiology, clinical presentation, differential diagnosis, potential pathogens, and management. We also provide recommendations for the selection, dosing, and duration of peri-operative antibiotic prophylaxis to minimize post-operative SSIs.

Toxoplasmosis in the non-orthotopic heart transplant recipient population, how common is it? Any indication for prophylaxis?

PURPOSE OF REVIEW

Unlike in orthotopic heart transplant (OHT) setting where toxoplasma prophylaxis is a standard practice in pretransplant toxoplasma seronegative recipients who have received donor hearts from seropositive donors (D+/R-), there is no consensus regarding prophylaxis in non-OHT recipients.

RECENT FINDINGS

The incidence of toxoplasma disease in non-OHT recipients is less than 1% but its true burden is underestimated. Among 31 cases of toxoplasma disease reported from 2004 through 2017, renal and liver transplant recipients comprised of 90% of cases. A total of 94% of 18 recipients with known pretransplant serology were seronegative recipients (mostly D+/R-). Out of 16 recipients with adequate information, 10 (63%) and five (31%) were deemed to be donor derived and nondonor-derived primary toxoplasmosis respectively. Tissue invasive reactivation was uncommon. Almost all cases were described in patients not on prophylaxis at the time of presentation. Universal screening of donor/recipient toxoplasma serology for risk stratification is beneficial as illustrated by reports of fatal cases of toxoplasmosis due to unavailability of positive donor serology results.

SUMMARY

Toxoplasma disease in non-OHT predominantly occurs in pretransplant seronegative recipients- mostly in D+/R- group and is rare in seropositive recipients. Posttransplant prophylaxis should be targeted against the high-risk D+/R- group and should be considered in seropositive recipients in whom unusually high immunosuppression is implemented. Toxoplasma serologies and PCR should be used in combination for the diagnosis of toxoplasmosis in non-OHT patients.

Diagnostic and therapeutic approach to infectious diseases in solid organ transplant recipients

Purpose

Prognosis of solid organ transplant (SOT) recipients has improved, mainly because of better prevention of rejection by immunosuppressive therapies. However, SOT recipients are highly susceptible to conventional and opportunistic infections, which represent a major cause of morbidity, graft dysfunction and mortality.

Methods

Narrative review.

Results

We cover the current epidemiology and main aspects of infections in SOT recipients including risk factors such as postoperative risks and specific risks for different transplant recipients, key points on anti-infective prophylaxis as well as diagnostic and therapeutic approaches. We provide an up-to-date guide for management of the main syndromes that can be encountered in SOT recipients including acute respiratory failure, sepsis or septic shock, and central nervous system infections as well as bacterial infections with multidrug-resistant strains, invasive fungal diseases, viral infections and less common pathogens that may impact this patient population.

Conclusion

We provide state-of the art review of available knowledge of critically ill SOT patients with infections.

Review article: the evidence that vancomycin is a therapeutic option for primary sclerosing cholangitis

BACKGROUND AND AIMS

PSC is an autoimmune biliary inflammatory disorder that is often associated with inflammatory bowel disease (IBD), with 50%-75% of patients with PSC having coexisting IBD, most commonly ulcerative colitis. Currently, no medical therapies have been shown to improve the disease course or slow its progression. However, ongoing research has resulted in a growing interest in the use of antibiotics for treatment of PSC, of which vancomycin is the most studied. In this review, we summarise the current evidence on the use of vancomycin in PSC and comment on future research areas of interest.

METHODS

A comprehensive PUBMED and EMBASE literature search for articles on vancomycin, PSC, therapeutic options and microbiome was performed.

RESULTS

Two randomised clinical trials, three case series and two case reports were included in the study. These include uncontrolled data from at least 98 patients that include promising improvements in biochemistry and imaging. Optimal dosing regimens are unclear.

CONCLUSION

Vancomycin is one of the most studied antibiotics used in the treatment of PSC with promising results. There is not currently sufficient evidence to support treatment recommendations. Further research is needed to establish if vancomycin is a PSC treatment.

Early infections in the intensive care unit after liver transplantation-etiology and risk factors: A single-center experience

BACKGROUND

Infectious complications represent one of the main causes of perioperative morbidity and mortality of liver transplant recipients. The primary objective of this retrospective observational study was to evaluate incidence and etiology of early (within 1 month from surgery and occurring in the intensive care unit [ICU]) postoperative infections as well as donor- and recipient-related risk factors.

METHODS

The data of 280 patients undergoing 299 consecutive liver transplant procedures from January 2012 to December 2015 were extracted from the Italian ICU registry database and hospital registries. Perioperative risk factors, etiology of infections, and antibiotic susceptibility of isolated microorganisms were taken into consideration.

RESULTS

Global incidence of postoperative infections was 21%. Pneumonia was the most frequent infection and, globally, gram-negative bacteria were the most common agents. Septic shock was present in 22% of infection cases and hospital mortality was higher in patients with postoperative infection. Preoperative chronic obstructive pulmonary disease, malnutrition, preoperative ascites, encephalopathy, and early re-transplantation were significantly associated to post orthotopic LT infections.

CONCLUSION

Infections represent a major cause of early postoperative morbidity and mortality. The impact of single risk factors and the results of their preoperative management should be further investigated in order to reduce the incidence and evolution of postoperative infections.

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.

Surgical Site Infections After Liver Transplantation: Prospective Surveillance and Evaluation of 250 Transplant Recipients in Canada

OBJECTIVE

To evaluate the incidence of surgical-site infections (SSIs) in a cohort of liver transplant recipients and to assess risk factors predisposing patients to these infections.

DESIGN

Prospective observational cohort study.

SETTING

Single transplant center in Canada.

PATIENTS

Patients who underwent liver transplantation between February 2011 and August 2014.

METHODS

Multivariate logistic regression was used to identify independent risk factors for SSIs in liver transplant patients.

RESULTS

We enrolled 250 liver transplant recipients. The recipients’ median age at the time of transplantation was 56 years (range, 19–70 years), and 166 patients (66.4%) were male. Moreover, 47 SSIs were documented in 43 patients (17.2%). Organ-space, superficial, and deep SSIs were noted in 29, 7, and 3 patients, respectively. In addition, 2 patients developed superficial and organ-space SSIs, and another 2 patients were found to have deep as well as organ-space infections. In total, we identified 33 organ-space SSIs (70.2%), 9 superficial SSIs (19.1%), and 5 deep SSIs (10.6%). Factors predictive of SSIs by multivariate analysis were duct-to-duct anastomosis (odds ratio [OR], 3.88; 95% CI, 1.85–8.13; P<.001) and dialysis (OR, 3.57; 95% CI, 1.02–12.50; P=.046). Of the 66 organisms isolated in both deep and organ-space SSIs, 55 (83%) were resistant to cefazolin.

CONCLUSIONS

Organ-space SSIs are a common complication after liver transplantation. Duct-to-duct anastomosis and dialysis were independent risk factors associated with SSIs. Appropriate perioperative prophylaxis targeting patients with duct-to-duct anastomosis and dialysis while simultaneously providing optimum coverage for the potential pathogens causing SSIs is warranted.

Infect Control Hosp Epidemiol 2017;38:1084–1090

Preventive Strategies Against Cytomegalovirus and Incidence of α-Herpesvirus Infections in Solid Organ Transplant Recipients: A Nationwide Cohort Study

We assessed the impact of antiviral preventive strategies on the incidence of herpes simplex virus (HSV) and varicella-zoster virus (VZV) infections in a nationwide cohort of transplant recipients. Risk factors for the development of HSV or VZV infection were assessed by Cox proportional hazards regression. We included 2781 patients (56% kidney, 20% liver, 10% lung, 7.3% heart, 6.7% others). Overall, 1264 (45%) patients received antiviral prophylaxis (ganciclovir or valganciclovir, n = 1145; acyclovir or valacyclovir, n = 138). Incidence of HSV and VZV infections was 28.9 and 12.1 cases, respectively, per 1000 person-years. Incidence of HSV and VZV infections at 1 year after transplant was 4.6% (95% confidence interval [CI] 3.5-5.8) in patients receiving antiviral prophylaxis versus 12.3% (95% CI 10.7-14) in patients without prophylaxis; this was observed particularly for HSV infections (3% [95% CI 2.2-4] versus 9.8% [95% CI 8.4-11.4], respectively). A lower rate of HSV and VZV infections was also seen in donor or recipient cytomegalovirus-positive patients receiving ganciclovir or valganciclovir prophylaxis compared with a preemptive approach. Female sex (hazard ratio [HR] 1.663, p = 0.001), HSV seropositivity (HR 5.198, p < 0.001), previous episodes of rejection (HR 1.95, p = 0.004), and use of a preemptive approach (HR 2.841, p = 0.017) were significantly associated with a higher risk of HSV infection. Although HSV and VZV infections were common after transplantation, antiviral prophylaxis significantly reduced symptomatic HSV infections.

Surgical Site Infections After Liver Transplantation: Emergence of Multidrug-Resistant Bacteria and Implications for Prophylaxis and Treatment Strategies

BACKGROUND

Perioperative antimicrobial prophylaxis is administered to liver transplant (LTx) recipients to prevent surgical site infections (SSIs), but regimens are not standardized, and there are limited effectiveness data. Prevention and treatment of SSIs have been complicated by the emergence of multidrug-resistant (MDR) pathogens.

METHODS

We retrospectively reviewed SSIs among 331 LTx recipients at our center in 2010 to 2014.

RESULTS

Culture-proven superficial and deep SSIs occurred in 3% and 15% of patients, respectively, at median 12.5 and 13.5 days post-LTx. Recipients with superficial SSIs and those without SSIs were similar in demographics, clinical characteristics, length of hospital stay, and mortality. Deep SSIs included abscesses (58%), peritonitis (28%), deep incisional infections (8%), and cholangitis (6%). Rates of deep SSIs were comparable among patients receiving prophylaxis with ampicillin-sulbactam, aztreonam and vancomycin, or tigecycline (P = 0.61). Independent risk factors for deep SSIs were bile leak (P < 0.001) and operative time (P < 0.001). Enterobacteriaceae (42%), Enterococcus spp. (24%), and Candida spp. (15%) were predominant pathogens. Fifty-three percent of bacteria were MDR, including 95% of Enterococcus faecium and 55% of Enterobacteriaceae; 82% of deep SSIs were caused by bacteria resistant to antimicrobials used for prophylaxis, and 58% of patients were treated with an inactive empiric regimen. Deep SSIs were associated with longer lengths of stay (P < 0.001), and higher 90-day and long-term mortality rates (P < 0.001).

CONCLUSIONS

Deep SSIs, including those caused by MDR bacteria, were common after LTx despite prophylaxis with broad-spectrum antimicrobials. Rather than altering prophylaxis regimens, programs should devise empiric treatment regimens that are directed against the most common local pathogens.

Factors influencing mortality in abdominal solid organ transplant recipients with multidrug-resistant gram-negative bacteremia

Background

Although multidrug-resistant (MDR) gram-negative bacteremia (GNB) has been recognized as an important cause of morbidity and mortality among abdominal solid organ transplant (ASOT) recipients, there are no data on its prognostic factors after an interim standard definition of MDR was proposed in 2012. The objective of this study was to describe the epidemiology, microbiology, and predictors of infection-related 30-day mortality in ASOT recipients with MDR GNB.

Methods

We performed a retrospective, double-center analysis of ASOT patients with MDR GNB over a 13-year study period. Univariate and multivariate analyses were performed to identify the risk factors for mortality.

Results

During the observational period, 2169 subjects underwent ASOT. Ninety-nine episodes of MDR GNB were diagnosed in 91 (4.6%) ASOT recipients, with a predominance of E.coli (29 isolates, 29.3%) and A.baumanii (24 isolates, 24.2%). The median age of these 91 recipients was 45 years (interquartile range 35–54). Mortality after the first episode of MDR GNB was 39.6% (36 deaths). The univariate analysis identified the following variables as predictors of MDR GNB-related mortality: lung focus (P = 0.001),nosocomial origin (P = 0.002), graft from donation after cardiac death or deceased donors (P = 0.023), presence of other concomitant bloodstream infection (P < 0.001), temperature of 40 °C or greater at the onset of MDR GNB (P = 0.039), creatinine > 1.5 mg/dl (P = 0.006), albumin < 30 g/L (P = 0.009), platelet count < 50,000/mm³ (P < 0.001), and septic shock (P < 0.001). In the multivariate logistic regression analysis, septic shock (odds ratio (OR) = 160.463, 95% confidence interval (CI) = 19.377–1328.832, P < .001), as well as creatinine > 1.5 mg/dl (OR = 24.498, 95% CI = 3.449–173.998, P = 0.001), nosocomial origin (OR = 23.963, 95% CI = 1.285–46.991, P = 0.033), and presence of other concomitant bloodstream infections (OR = 27.074, 95% CI = 3.937–186.210, P = 0.001) were the variables associated with MDR GNB-related 30-day mortality.

Conclusions

MDR GNB was associated with high morbidity and mortality in ASOT recipients, with a predominant causative organisms being E.coli and A.baumanii. Nosocomial origin, as well as presence of other concomitant bloodstream infections, increased creatinine level and septic shock were the main predictors of MDR GNB-related 30-day mortality.

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.

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.

Approach to the Solid Organ Transplant Patient with Suspected Fungal Infection

In solid organ transplant (SOT) recipients, invasive fungal infections (IFIs) are associated with significant morbidity and mortality. Detection of IFIs can be difficult because the signs and symptoms are similar to those of viral or bacterial infections, and diagnostic techniques have limited sensitivity and specificity. Clinicians must rely on knowledge of the patient's risk factors for fungal infection to make a diagnosis. The authors describe their approach to the SOT recipient with suspected fungal infection. The epidemiology of IFIs in the SOT population is reviewed, and a syndromic approach to suspected IFI in SOT recipients is described.

Bacterial and fungal infections in the early post-transplantation period after liver transplantation: etiologic agents and their susceptibility

OBJECTIVE

It has been reported in many studies that one of the main factors influencing morbidity and mortality in patients receiving transplants is infection after transplantation.

PATIENTS AND METHODS

The study included 190 adult patients undergoing orthotopic liver transplantation (OLT) between September 2001 and December 2007. All the patients were followed prospectively for infections from the OLT date and during the first 4 weeks after surgery. Immunosuppression consisted of steroids and tacrolimus. Antimicrobial prophylaxis included piperacillin/tazobactam, fluconazole, and selective bowel decontamination (SBD) was performed. Samples of clinical materials were investigated for microbiological cultures. The micro-organisms were cultured and identified in accordance with standard bacteriological procedures. Susceptibility testing was performed using Clinical and Laboratory Standards Institute procedures.

RESULTS

From 190 OLT recipients, 2213 clinical samples were obtained for microbiological examination. Positive cultures were found in 27.2% (n = 603) of all samples tested; 1252 strains were collected. Gram-positive bacteria were found in 64.1% (n = 802), Gram-negative bacteria were found in 31.6% (n = 396), and fungal strains were isolated in 4.3% (n = 54). Surgical site specimens (n = 1031) were obtained from 190 recipients during the first month after transplantation. Positive cultures accounted for 29.2% (n = 301) of all samples tested. Among the isolated microbial strains (n = 677), most common were Gram-positive bacteria (73.7%; n = 499). Gram-negative bacteria comprised 25.1% (n = 170). There were fungal strains in 1.2% (n = 8). There were 539 urine specimens. Positive cultures accounted for 16.7% (n = 90) of those. Among the isolated microbial strains (n = 210), most common were Gram-negative bacteria (62.4%; n = 131). Gram-positive bacteria comprised 28.6% (n = 60) and fungi 9% (n = 19). There were 549 blood specimens. Positive cultures were found in 30.6% (n = 168) of all samples tested. Among the isolated microbial strains (n = 263), most common were Gram-positive bacteria in 72.3% (n = 190); Gram-negative bacteria were found in 26.2% (n = 69), and fungal strains were isolated in 1.5% (n = 4). There were 69 respiratory tract specimens. Positive cultures were found in 46.4% (n = 32) of all samples tested. Among the isolated microbial strains (n = 84), most common were Gram-positive bacteria (51.2%; n = 43); Gram-negative bacteria comprised 27.4% (n = 23) and fungi 21.4% (n = 18).

CONCLUSIONS

(1) Surgical site samples were predominated samples after LTx. (2) Our study showed Gram-positive bacteria were 64.1% (n = 802), Gram-negative bacteria, 31.6% (n = 396) and fungal strains isolated in 4.3% (n = 54). (3) The increased proportion of isolates of multi-drug-resistant bacterial strains (methicillin resistant coagulase negative Staphylococcus, vancomycin-resistant Enterococcus, high-level aminoglycoside resistance, and extended- spectrum β-lactamase). (4) These data indicate strict cooperation infection control procedures in these patients.

Bacterial and fungal infections in the early post-transplant period after kidney transplantation: etiological agents and their susceptibility

BACKGROUND

Infections remain serious complications in solid-organ transplant recipients, despite professional medical care, the introduction of new immunosuppressive drugs, and treatment that decreases the risk of infections.

METHODS

The study covered 295 adult patients undergoing kidney transplantation (KTx) between September 2001 and December 2007. All the patients were followed prospectively for infections from the KTx date and during the first 4 weeks after surgery. Samples of clinical materials were investigated for microbiological cultures. The microorganisms were cultured and identified in accordance with standard bacteriological procedures. Susceptibility testing was carried out through the use of Clinical and Laboratory Standards Institute procedures.

RESULTS

From 295 KTx recipients, 1073 clinical samples were taken for microbiological examination. Positive cultures were 26.9% (n = 289) of all samples tested; 525 strains were collected. Gram-positive bacteria were isolated in 52.2% (n = 274), Gram-negative bacteria were isolated in 40.8% (n = 214), and fungal strains were isolated in 7% (n = 37). Urine specimens (n = 582) were obtained from 84.5% of 245 recipients during the first month after transplantation. Among the isolated bacterial strains (n = 291), the most common were Gram-negative bacteria (56.4%). Gram-positive bacteria comprised 35.7%; fungal strains were found in 23 cases (7.9%). In surgical site specimens (n = 309), Gram-positive bacteria (72.1%) were the most common. Gram-negative bacteria comprised 24.4%. In blood specimens (n = 138), Gram-positive bacteria (81.6%) were the most common. Gram-negative bacteria comprised 15.8%; fungi were isolated in 2.6%. In respiratory tract specimens (n = 13), among the isolated bacterial strains (n = 8), the most common were Gram-positive bacteria (57.1%). Gram-negative bacteria comprised 14.3%; fungi were isolated in 28.6%.

CONCLUSIONS

Urine samples were predominantly positive after KTx. Our study showed Gram-positive bacteria in 52.2% after kidney transplantation. The proportion of isolates of multi-drug-resistant bacterial strains (MRCNS, vancomycin-resistant strains, high-level aminoglycoside-resistant strains, extended-spectrum beta-lactamase producers, and high-level aminoglycoside-resistant strains) was increased. These data indicate the need for strict adherence to infection control procedures in these patients.

Risk Factors for Bloodstream Infection After Living-donor Liver Transplantation in Children

BACKGROUND

Postoperative bloodstream infection (BSI) is the most important determinant of recipient morbidity and mortality after liver transplantation (LT). Children who underwent LT are at the highest risk of developing BSI because of the significant surgical intervention, use of multiple devices, and administration of immunosuppressive agents. However, information regarding the risk factors for BSI in children after LT is limited.

METHODS

We retrospectively reviewed 210 children who underwent living-donor LT at the largest pediatric LT center in Japan. Patients' characteristics, blood culture results and clinical outcomes were extracted from electronic medical records. Univariate and multivariate analyses were performed to identify the risk factors for BSI.

RESULTS

Among the 210 LT recipients, 53 (25%) recipients experienced 86 episodes of BSI during the observational period. The source of the BSI was identified only in 38%: catheter-related BSI (27%) peritonitis (7%), urinary tract infection (2%), pneumonia (1%) and infectious endocarditis (1%). A multivariate analysis demonstrated that body weight (P = 0.03), volume of blood loss during LT (P < 0.001) and cytomegalovirus (CMV) antigenemia positivity (P = 0.04) were independently associated with the development of BSI. The risk factors for BSI differed when we analyzed the subjects according to age (≤24 months and >24 months), blood loss and pediatric end-stage liver disease/model for end-stage liver disease versus positive CMV antigenemia.

CONCLUSIONS

The volume of blood loss, postoperative CMV antigenemia positivity and body weight were associated with the development of BSI after LT in pediatric living-donor recipients. To identify the age-specific predictors of BSI in children who underwent LT, age-specific analyses are crucial.

Predictors of mortality in solid-organ transplant recipients with infections caused by Acinetobacter baumannii

Acinetobacter baumannii can cause a serious infection in solid-organ transplant (SOT) recipients, and more data on A. baumannii infection is needed. We sought to investigate the epidemiology and distribution of A. baumannii isolates in SOT recipients. We also investigated the risk factors for overall in-hospital mortality and infection-related 30-day mortality using multivariate logistic regression analysis. A double-center retrospective study of SOT recipients who were infected with A. baumannii between January 2003 and January 2015 was conducted. A total of 71 individuals developed 93 episodes of A. baumannii infection, with a mean age of 44.5 years (44.5±11.9 years). Ninety percent of recipients had nosocomial origin A. baumannii infection, with the bloodstream as the most common site of infection (32.4%). Septic shock developed in 23.9% (17 of 71) of all recipients with A. baumannii infection. Morbidity and mortality rates of A. baumannii infections were high in SOT recipients. The incidence rate of A. baumannii infection in SOT recipients was 3.9% (71 of 1,821). Overall in-hospital mortality and infection-related 30-day mortality were 53.5% (38 of 71) and 40.8% (29 of 71), respectively. Risk factors independently associated with overall in-hospital mortality were mechanical ventilation at onset of A. baumannii infection (odds ratio [OR] 6.29, 95% confidence interval [CI] 1.48–26.85; P=0.013), liver or liver–kidney transplantation (OR 15.33, 95% CI 1.82–129.18; P=0.012), and late-onset A. baumannii infection (OR 7.61, 95% CI 1.07–54.36; P=0.043). A platelet count <50,000/mm³ (OR 12.76, 95% CI 1.28–126.81; P=0.030) and mechanical ventilation at onset of A. baumannii infection (OR 189.98, 95% CI 13.23–2,728.81; P<0.001) were identified as independent risk factors for infection-related 30-day mortality. In conclusion, the morbidity and mortality rates of A. baumannii infections were high in SOT recipients. Mechanical ventilation at onset of A. baumannii infection was associated with higher overall in-hospital mortality and infection-related mortality. For overall in-hospital mortality, liver or liver–kidney transplantation and late-onset A. baumannii infection, and for infection-related mortality, thrombocytopenia were also risk factors, respectively.

Sepsis in the severely immunocompromised patient

The prevention and treatment of sepsis in the immunocompromised host present a challenging array of diagnostic and management issues. The neutropenic patient has a primary defect in innate immune responses and is susceptible to conventional and opportunistic pathogens. The solid organ transplant patient has a primary defect in adaptive immunity and is susceptible to a myriad of pathogens that require an effective cellular immune response. Risk for infections in organ transplant recipients is further complicated by mechanical, vascular, and rejection of the transplanted organ itself. The immune suppressed state can modify the cardinal signs of inflammation, making accurate and rapid diagnosis of infection and sepsis difficult. Empiric antimicrobial agents can be lifesaving in these patients, but managing therapy in an era of progressive antibiotic resistance has become a real issue. This review discusses the challenges faced when treating severe infections in these high-risk patients.

Distribution and resistance of pathogens in liver transplant recipients with Acinetobacter baumannii infection

BACKGROUND

Drug-resistant Acinetobacter baumannii has become a major problem in liver transplant recipients. The aim of this study was to investigate the clinical presentation, distribution, and drug susceptibility characteristics in liver recipients with A. baumannii infection.

METHODS

We retrospectively investigated 17 liver recipients who developed A. baumannii infection between January 1, 2007 and December 31, 2014. The distribution of A. baumannii and drug susceptibility characteristics were reviewed.

RESULTS

Infectious complications due to A. baumannii appeared in 17 liver recipients, with a total of 24 episodes. Approximately 63% (15/24) of A. baumannii infections occurred within 2 weeks after transplantation. The most common source of infection was multiple culture-positive sites (35.3%, n=6), followed by the intra-abdominal/biliary tract (23.5%, n=4) and lung (23.5%, n=4). Eight patients (47.1%) had a body temperature of 38°C or higher at the onset of A. baumannii infection. Nine, seven, and 12 recipients had a serum creatinine level of >1.5 mg/dL, a white blood cell count of >15,000/mm(3), and a platelet count of <50,000/mm(3), respectively. There were five (29.4%) cases of septic shock and eight (47.1%) deaths. The rate of antibiotic resistance of A. baumannii to ten of 12 antibiotics investigated was more than 60%. Among the 24 infections caused by A. baumannii, 75% were carbapenem-resistant. The rods were relatively sensitive to tigecycline and cefoperazone-sulbactam.

CONCLUSION

The clinical manifestations of A. baumannii infection included a high body temperature, a decreased platelet count, an elevated white blood cell count, and onset in the early period after transplantation as well as high mortality. The antibiotic resistance rate of A. baumannii was extremely high. Prevention measures and combination antibiotic therapy are needed to improve the outcomes of liver recipients with A. baumannii infections.

Distribution and resistance of pathogens in liver transplant recipients with Acinetobacter baumannii infection

Background

Drug-resistant Acinetobacter baumannii has become a major problem in liver transplant recipients. The aim of this study was to investigate the clinical presentation, distribution, and drug susceptibility characteristics in liver recipients with A. baumannii infection.

Methods

We retrospectively investigated 17 liver recipients who developed A. baumannii infection between January 1, 2007 and December 31, 2014. The distribution of A. baumannii and drug susceptibility characteristics were reviewed.

Results

Infectious complications due to A. baumannii appeared in 17 liver recipients, with a total of 24 episodes. Approximately 63% (15/24) of A. baumannii infections occurred within 2 weeks after transplantation. The most common source of infection was multiple culture-positive sites (35.3%, n=6), followed by the intra-abdominal/biliary tract (23.5%, n=4) and lung (23.5%, n=4). Eight patients (47.1%) had a body temperature of 38°C or higher at the onset of A. baumannii infection. Nine, seven, and 12 recipients had a serum creatinine level of >1.5 mg/dL, a white blood cell count of >15,000/mm³, and a platelet count of <50,000/mm³, respectively. There were five (29.4%) cases of septic shock and eight (47.1%) deaths. The rate of antibiotic resistance of A. baumannii to ten of 12 antibiotics investigated was more than 60%. Among the 24 infections caused by A. baumannii, 75% were carbapenem-resistant. The rods were relatively sensitive to tigecycline and cefoperazone-sulbactam.

Conclusion

The clinical manifestations of A. baumannii infection included a high body temperature, a decreased platelet count, an elevated white blood cell count, and onset in the early period after transplantation as well as high mortality. The antibiotic resistance rate of A. baumannii was extremely high. Prevention measures and combination antibiotic therapy are needed to improve the outcomes of liver recipients with A. baumannii infections.

Epidemiology, Diagnosis, and Therapy of Fungal Infections in Surgery

Over the past decade, the incidence of hospital-acquired bloodstream infections caused byCandidastrains has risen, while the implicated species have changed.Candida tropicalis, Candida parapsilosis, andCandida glabrataall have increased in incidence. Data from the Centers for Disease Control and Prevention reveal that, between 1980 and 1990,Candidaemerged as the sixth most common nosocomial pathogen (7.2.%) and was the fourth most common pathogen in nosocomial bloodstream infections, surpassed only by coagulase-negative staphylococci,Staphylococcus aureus, and enterococci. The incidence of candidemia is dramatically higher in high-risk critical-care units: 25% of cases occur in surgical intensive-care units (ICUs) versus 25% in bone marrow transplantation units, 20% in medical ICUs, 20% in general medical wards, and 10% in oncology-hematology units. Burns and gastrointestinal surgery predispose to nosocomial candidemia. Independent risk factors include prior therapy with multiple antibiotics, isolation ofCandidafrom sites other than blood, and prior hemodialysis. Crude mortality exceeds 55% and is associated with older age and concomitant renal failure, hepatic failure, acute respiratory diseases, or postoperative shock. In addition to extreme vigilance for early recognition ofCandidasepsis in critically ill surgical patients, the high risk for candidemia probably necessitates fungal surveillance cultures and initiation of preemptive antifungal therapy in high-risk surgical patients.

Multidrug-resistant Gram-negative bacteria in solid organ transplant recipients with bacteremias

Bloodstream infections (BSIs) remain as life-threatening complications and are associated with significant morbidity and mortality among solid organ transplant (SOT) recipients. Multidrug-resistant (MDR) Gram-negative bacteria can cause serious bacteremias in these recipients. Reviews have aimed to investigate MDR Gram-negative bacteremias; however, they were lacking in SOT recipients in the past. To better understand the characteristics of bacteremias due to MDR Gram-negative bacteria, optimize preventive and therapeutic strategies, and improve the outcomes of SOT recipients, this review summarize the epidemiology, clinical and laboratory characteristics, and explores the mechanisms, prevention, and treatment of MDR Gram-negative bacteria.