Infección nosocomial en el paciente receptor de un trasplante de órgano sólido o de precursores hematopoyéticos

Bacterial infections are the most common infections in solid organ transplant recipients. These infections occur mainly in the first month after transplantation and are hospital-acquired. Nosocomial infections cause significant morbidity and are the most common cause of mortality in this early period of transplantation. These infections are caused by multi-drug resistant (MDR) microorganisms, mainly Gram-negative enterobacteria, non-fermentative Gram-negative bacilli, enterococci, and staphylococci. The patients at risk of developing nosocomial bacterial infections are those previously colonized with MDR bacteria while on the transplant waiting list. Intravascular catheters, the urinary tract, the lungs, and surgical wounds are the most frequent sources of infection. Preventive measures are the same as those applied in non-immunocompromised, hospitalized patients except in patients at high risk for developing fungal infection. These patients need antifungal therapy during their hospitalization, and for preventing some bacterial infections in the early transplant period, patients need vaccinations on the waiting list according to the current recommendations. Although morbidity and mortality related to infectious diseases have decreased during the last few years in haematopoietic stem cell transplant recipients, they are still one of the most important complications in this population. Furthermore, as occurs in the general population, the incidence of nosocomial infections has increased during the different phases of transplantation. It is difficult to establish general preventive measures in these patients, as there are many risk factors conditioning these infections. Firstly, they undergo multiple antibiotic treatments and interventions; secondly, there is a wide variability in the degree of neutropenia and immunosuppression among patients, and finally they combine hospital and home stay during the transplant process. However, some simple measures could be implemented to improve the current situation.     

Cytomegalovirus and chronic allograft rejection in liver transplantation

Cytomegalovirus (CMV) remains one of the most frequent viral infections and the most common cause of death after liver transplantation (LT). Chronic allograft liver rejection remains the major obstacle to long-term allograft survival and CMV infection is one of the suggested risk factors for chronic allograft rejection. The precise relationship between cytomegalovirus and chronic rejection remains uncertain. This review addresses the morbidity of cytomegalovirus infection and the risk factors associated with it, the relationship between cytomegalovirus and chronic allograft liver rejection and the potential mechanisms of it.     

原位肝移植术后肺部感染及危险因素分析

目的探讨原位肝移植术后肺部感染的特点及其危险因素，以提高肝移植术后肺部感染的诊治水平。方法对250例原位肝移植术后肺部感染患者的资料进行了回顾性分析，以术前、术中及术后主要的临床表现和实验室指标作为研究对象，分析肺部感染组和对照组间的差别。结果250例原位肝移植患者中，57例术后共发生肺部感染72次，肺部感染率为22．8％（57／250）。最常见为细菌感染，单一细菌感染36例次，两种细菌感染5例次，多种细菌同时感染6例次。其次为真菌感染13例次，占18．1％（13／72），其中7例次合并细菌感染。病毒感染12例次，占16．7％（12／72），均为巨细胞病毒感染，其中3例次合并细菌感染。肺部感染组术后1、2、3年生存率分别为71．9％、61．4%、53．4%，对照组分别为93．1％、75．8％、67．2％（P〈0．05）。Logistic回归分析表明肝移植患者有术前感染、机械通气时间大于12h、手术时间、术中输血总量〉1000 ml、术后再次手术史、术后胸水、重症监护室住院天数这7个因素是术后肺部感染的独立危险因素。结论肺部感染以细菌感染为主，但多种病原菌的混合感染以及多重耐药菌日益增多。在临床工作中应重视对相关危险因素的控制，早期诊断、早期治疗是治疗成功的关键。     

Infectious complications in the early postoperative period in liver transplant patients

Liver transplantation (LTx) is a technically well established procedure in acute and in end-stage liver diseases. However, opportunistic infections remain one of the important complications in short and long-term outcome of LTx patients. Bloodstream and pulmonary infections are the major cause of death in the first year following liver transplantation. Due to extended use of chinolons and third generation cephalosporines there is a shift towards multidrug-resistant bacteria including methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus faecium, and extended b-lactamase-producing gram negative rods. Fungal infections are mainly due to Candida spp. Viral infections, such as with cytomegalovirus, human herpesvirus 6, herpes simplex virus, and Epstein-Barr virus infections are another major cause of morbidity in patients receiving solid organ transplants, including liver transplant patients. Studies of infection following LTx are necessary to improve management and to provide a better outcome after LTx. This review focuses on the most important bacterial, fungal and viral infections in LTx patients.     

Natural history,treatment and prevention of hepatitis C recurrence after liver transplantation: Past,present and future

Hepatitis C virus (HCV)-related liver disease, including cirrhosis and hepatocellular carcinoma is the main indication for liver transplantation (LT) worldwide. Post-transplant HCV re-infection is almost universal and results in accelerated progression from acute hepatitis to chronic hepatitis, and liver cirrhosis. Comprehension and treatment of recurrent HCV infection after LT have been major issues for all transplant hepatologists and transplant surgeons for the last decades. The aim of this paper is to review the evolution of our knowledge on the natural history of HCV recurrence after LT, including risk factors for disease progression, and antiviral therapy. We will focus our attention on possible ways (present and future) to improve the final long-term results of LT for HCV-related liver disease.     

肺移植术后早期细菌感染的研究进展

肺移植是世界上公认的治疗终末期肺疾病的一种有效手段。随着肺移植术的飞速发展,肺移植患者术后生存率及生存质量明显提高。肺部感染不仅是肺移植术后最常见的并发症,也是术后最常见的致死因素,其中细菌感染最常见。肺移植术后的感染也造成了患者病死率的上升。该文对肺移植术后细菌感染的现状、病原体来源、感染风险因素、诊断及防治的进展作一综述。     

Selective intestinal decontamination for the prevention of early bacterial infections after liver transplantation

Bacterial infection in the first month after liver transplantation is a frequent complication that poses a serious risk for liver transplant recipients as contributes substantially to increased length of hospitalization and hospital costs being a leading cause of death in this period. Most of these infections are caused by gramnegative bacilli, although gram-positive infections, especially Enterococcus sp. constitute an emerging infectious problem. This high rate of early postoperative infections after liver transplant has generated interest in exploring various prophylactic approaches to surmount this problem. One of these approaches is selective intestinal decontamination(SID). SID is a prophylactic strategy that consists of the administration of antimicrobials with limited anaerobicidal activity in order to reduce the burden of aerobic gram-negative bacteria and/or yeast in the intestinal tract and so prevent infections caused by these organisms. The majority of studies carried out to date have found SID to be effective in the reduction of gram-negative infection, but the effect on overall infection is limited due to a higher number of infection episodes by pathogenic enterococci and coagulase-negative staphylococci. However, difficulties in general extrapolation of the favorable results obtained in specific studies together with the potential risk of selection of multirresistant microorganisms has conditioned controversy about the routinely application of these strategies in liver transplant recipients.     

86例肝移植术后抗菌素使用的合理性分析

目的 分析肝移植术后细菌性感染的特征、抗菌素使用与细菌性感染之间的关系,评价肝移植术后抗菌素使用的合理性,探讨预防高水平耐药细菌性感染的措施. 方法回顾性分析86例肝移植术后感染的主要病原菌、抗菌素使用量,采用限定日剂量、用药频度、药物利用指数评价抗菌素使用的合理性,运用三维试验检测革兰阴性杆菌产超广谱β-内酰胺酶、AmpC β-内酰胺酶情况.结果 肝移植术后感染主要病原菌为粪肠球菌、阴沟肠杆菌、真菌,大肠杆菌,术前抗菌素使用率为83.7%,以单一抗菌素使用为主,术后抗菌素使用率达100.0%,以二联、三联抗菌素使用为主,抗菌素使用量居前3位为头孢菌素、含酶抑制剂复合抗菌素与青霉素类抗菌素,药物利用指数大于1.1的抗菌素包括氨苄西林、替考拉林,革兰阴性杆菌产超广谱β-内酰胺酶、AmpCβ-内酰胺酶分别为43.3%,31.8%,同时产两种酶的细菌占21.3%. 结论肝移植术后细菌性感染发生率高,抗菌素使用量大,频率高,抗菌素使用基本合理,易发生高耐药性细菌性感染,预防高耐药性细菌性感染十分重要.     

High mortality associated with gram-negative bacterial bloodstream infection in liver transplant recipients undergoing immunosuppression reduction

BACKGROUNDImmunosuppression is an important factor in the incidence of infections in transplant recipient. Few studies are available on the management of immunosuppression (IS) treatment in the liver transplant (LT) recipients complicated with infection. The aim of this study is to describe our experience in the management of IS treatment during bacterial bloodstream infection (BSI) in LT recipients and assess the effect of temporary IS withdrawal on 30 d mortality of recipients presenting with severe infection.AIMTo assess the effect of temporary IS withdrawal on 30 d mortality of LT recipients presenting with severe infection.METHODSA retrospective study was conducted with patients diagnosed with BSI after LT in the Department of Liver Surgery, Renji Hospital from January 1, 2016 through December 31, 2017. All recipients diagnosed with BSI after LT were included. Univariate and multivariate Cox regression analysis of risk factors for 30 d mortality was conducted in the LT recipients with Gram-negative bacterial (GNB) infection.RESULTSSeventy-four episodes of BSI were identified in 70 LT recipients, including 45 episodes of Gram-positive bacterial (GPB) infections in 42 patients and 29 episodes of GNB infections in 28 patients. Overall, IS reduction (at least 50% dose reduction or cessation of one or more immunosuppressive agent) was made in 28 (41.2%) cases, specifically, in 5 (11.9%) cases with GPB infections and 23 (82.1%) cases with GNB infections. The 180 d all-cause mortality rate was 18.5% (13/70). The mortality rate in GNB group (39.3%, 11/28) was significantly higher than that in GPB group (4.8%, 2/42) (P = 0.001). All the deaths in GNB group were attributed to worsening infection secondary to IS withdrawal, but the deaths in GPB group were all due to graft-versus-host disease. GNB group was associated with significantly higher incidence of intra-abdominal infection, IS reduction, and complete IS withdrawal than GPB group (P < 0.05). Cox regression showed that rejection (adjusted hazard ratio 7.021, P = 0.001) and complete IS withdrawal (adjusted hazard ratio 12.65, P = 0.019) were independent risk factors for 30 d mortality in patients with GNB infections after LT. CONCLUSIONIS reduction is more frequently associated with GNB infection than GPB infection in LT recipients. Complete IS withdrawal should be cautious due to increased risk of mortality in LT recipients complicated with BSI.IS     

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

AIM: To identify factors related to serious postoperative bacterial and fungal infections in the first 3 mo after living donor liver transplantation (LDLT).METHODS: In the present study, the data of 207 patients from 2004 to 2011 were reviewed. The pre-, intra- and post-operative factors were statistically analyzed. All transplantations were approved by the ethics committee of West China Hospital, Sichuan University. Patients with definitely preoperative infections and infections within 48 h after transplantation were excluded from current study. All potential risk factors were analyzed using univariate analyses. Factors significant at a P < 0.10 in the univariate analyses were involved in the multivariate analyses. The diagnostic accuracy of the identified risk factors was evaluated using receiver operating curve.RESULTS: The serious bacterial and fungal infection rates were 14.01% and 4.35% respectively. Enterococcus faecium was the predominant bacterial pathogen, whereas Candida albicans was the most common fungal pathogen. Lung was the most common infection site for both bacterial and fungal infections. Recipient age older than 45 years, preoperative hyponatremia, intensive care unit stay longer than 9 d, postoperative bile leak and severe hyperglycemia were independent risk factors for postoperative bacterial infection. Massive red blood cells transfusion and postoperative bacterial infection may be related to postoperative fungal infection.CONCLUSION: Predictive risk factors for bacterial and fungal infections were indentified in current study. Pre-, intra- and post-operative factors can cause postoperative bacterial and fungal infections after LDLT.     

The challenge of urinary tract infections in renal transplant recipients

Urinary tract infections (UTI) are an important cause of morbidity and mortality in renal transplant patients. These infections are quite common, and the goal of care is to identify and reduce risk factors while providing effective prophylaxis and treatment. Better understanding of long‐term outcomes from these infections has led to the distinctions among UTI, recurrent UTI, and asymptomatic bacteriuria (ASB), and that each requires a different therapeutic approach. Specifically, new research has supported the perspective that asymptomatic bacteriuria should not be treated. Symptomatic UTI, on the other hand, requires intervention and remains an ongoing challenge for infectious disease clinicians. Many bacteria species are responsible for UTI in renal transplant patients, and in recent years there has been a global rise in infection caused by bacteria with newly acquired antibacterial resistance genes. Many renal transplant patients who experience UTI will also have multiple recurring episodes, which likely has a distinct pathophysiological mechanism leading to chronic colonization of the urinary tract. In these cases, long‐term management includes bacterial suppression, which aims to reduce rather than eliminate bacteria to levels below the threshold for symptomatic infection. This review will address the current understanding of UTI epidemiology, pathogenesis, and risk factors in the renal transplant community, and also focus on current prevention and treatment strategies for patients who face an environment of increasingly antibiotic‐resistant bacteria.     

Infections after liver transplantation in adults: data from a university hospital in southern Brazil (1996-2000)

BACKGROUND: Infections after liver transplantations are the most important cause of morbi-mortality. In this study, we assessed the main characteristics of these infections in a southern Brazilian university hospital. METHODS: We conducted a retrospective cohort with 55 patients who underwent orthotopic liver transplantation between 1996 and 2000 in the "Hospital de Clínicas de Porto Alegre", Porto Alegre, RS, Brazil, to characterize the infections that occurred in the group. RESULTS: One or more infections (average 2.10) were diagnosed in 47 patients, especially during the first month after transplantation. The most common were bacteremia, intra-abdominal infections and pneumonia, predominantly with bacteria, especially Staphylococcus sp (and particularly S. aureus) and E. coli. The mortality rate attributed to infections was high: 17 cases of all deaths (total 27 deaths). Significant risk factors for infections included reoperation, diabetes, biliary stenosis and higher Child-Pugh scores. CONCLUSION: Infections remain a severe threat in liver transplant patients, and special efforts should be made to prevent and manage them correctly.     

Incidence and risk factors for infections after liver transplant: single‐center experience at the University Hospital Fundación Santa Fe de Bogotá, Colombia

A. Vera, F. Contreras, F. Guevara. Incidence and risk factors for infections after liver transplant: single‐center experience at the University Hospital Fundación Santa Fe de Bogotá, Colombia.
Transpl Infect Dis 2011: 13: 608–615. All rights reserved Abstract: The incidence of infections in liver transplant patients is higher compared with recipients of other organs, and infections are one of the major complications after transplantation. The aim of our study was to evaluate the incidence, presentation and risk factors of infections in liver transplant recipients in a Latin‐American population, and to compare the results with data worldwide. We performed a retrospective analysis of 94 consecutive patients undergoing liver transplantation between 2004 and 2008 at the University Hospital Fundación Santa Fe de Bogotá, Colombia. The patients contributed a total of 64.4 person years (PY). Fifty‐two patients (55.3%) developed one or more infections, in total 83 events (128.9 infections/100 PY). Bacterial infections represented the most frequent event (71.1%), followed by viral (19.3%) and fungal infections (8.4%). In 1%, no causative organism was identified. More than one‐third of infections (37%) occurred during the first 30 days, whereas 83% of all events were seen during the first 6 months. The most common site of pathogen localization was the bloodstream (25.3%), followed by the urinary tract (15.7%), liver with bile tract (14.5%), abdomen (10.8%), surgical site (7.2%), and lungs (9.6%). The overall mortality after 1 year was 14.9%, and 57.1% of the deaths were attributed to infections. We found that risk factors significantly associated with increased incidence rate ratio for infection were prolonged stay at the intensive care unit, the need for parenteral nutrition, and blood transfusion requirement. Our data provide additional information about etiology and epidemiology of infections after liver transplantation.     

Bacterial infections post-living-donor liver transplantation in Egyptian hepatitis C virus-cirrhotic patients: A singlecenter study

AIM To determine risk factors, causative organisms and antimicrobial resistance of bacterial infections following living-donor liver transplantation(LDLT) in cirrhotic patients.METHODS This prospective study included 45 patients with hepatitis C virus-related end-stage liver disease who underwent LDLT at Ain Shams Center for Organ Transplant, Cairo, Egypt from January 2014 to November 2015. Patients were followed-up for the first 3 mo after LDLT for detection of bacterial infections. All patients were examined for the possible risk factors suggestive of acquiring infection pre-, intra-and post-operatively. Positive cultures based on clinical suspicion and patterns of antimicrobial resistance were identified. RESULTS Thirty-three patients(73.3%) suffered from bacterial infections; 21 of them had a single infection episode, and 12 had repeated infection episodes. Bile was the most common site for both single and repeated episodes of infection(28.6% and 27.8%, respectively). The most common isolated organisms were gramnegative bacteria. Acinetobacter baumannii was the most common organism isolated from both single and repeated infection episodes(19% and 33.3%, respectively), followed by Escherichia coli for repeated infections(11.1%), and Pseudomonas aeruginosa for single infections(19%). Levofloxacin showed high sensitivity against repeated infection episodes(P = 0.03). Klebsiella, Acinetobacter and Pseudomonas were multi-drug resistant(MDR). Pre-transplant hepatocellular carcinoma(HCC) and duration of drain insertion(in days) were independent risk factors for the occurrence of repeated infection episodes(P = 0.024).CONCLUSION MDR gram-negative bacterial infections are common post-LDLT. Pre-transplant HCC and duration of drain insertion were independent risk factors for the occurrence of repeated infection episodes.     

Bacterial infection as a complication of liver transplantation: epidemiology and risk factors

A retrospective survey was undertaken to characterize the epidemiology of bacterial infection in 79 patients who underwent 103 operations for orthotopic liver transplantation. Fifty-four patients (68%) developed 115 bacterial infections (1.46 episodes per patient), and seven patients died as a result of these infections. Fifty-three percent of bacterial infections occurred within 2 weeks after transplantation and were designated as early infections. The most common sites of infection were the abdomen (35 cases), the bloodstream (31 cases), and the surgical wound (19 cases). Aerobic enteric gram-negative bacilli were the predominant pathogens, and other pathogenic organisms were enterococci, staphylococci, and Pseudomonas bacteria. Logistic regression analysis identified prolonged duration of surgery (greater than or equal to 8 hours) and an elevated bilirubin level (greater than or equal to 12 mg/dL) as risk factors for early bacterial infection at any site; risk factors for abdominal or wound infection were prolonged duration of surgery, increased operative transfusion requirement (greater than or equal to 2 blood volumes), and prior hepatobiliary surgery. Awareness of the sites, pathogens, and time of onset of bacterial infection provides a basis for improved prophylaxis and empiric therapy.     

Nosocomial infections within the first month of solid organ transplantation

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

Pseudomonas aeruginosa infection after living-donor liver transplantation in adults

Objectives. Pseudomonas aeruginosa infection is a major cause of bacterial infection after deceased-donor liver transplantation. The incidence and risk factors of P. aeruginosa infection after living-donor liver transplantation (LDLT), however, are not known.
Methods. We retrospectively reviewed the data from 170 adult patients who underwent LDLT at the University of Tokyo Hospital. The microbiologic and medical records of the patients from admission to 3 months after LDLT were reviewed. Uni- and multivariate analyses were performed to identify the independent risk factors for postoperative P. aeruginosa infection.
Result. Preoperative P. aeruginosa carriage was identified in 15 (9%) patients. Only 2 of the 15 patients later presented with postoperative P. aeruginosa infection. Postoperative P. aeruginosa infection occurred in 27 (16%) of 170 patients by median postoperative day 38. Among those 27 patients, surgical site infections were recorded in 8 (30%) and intra-abdominal infections in 14 (52%). In 5 of the 27 (19%) patients, P. aeruginosa isolates were multiple antimicrobial resistant. Postoperative bile leakage independently predicted postoperative P. aeruginosa infection.
Conclusion. P. aeruginosa infections were frequently detected after LDLT, including those by multiple antimicrobial-resistant isolates. Postoperative bile leakage predisposed patients to P. aeruginosa infection. Surveillance culture should be checked periodically after LDLT to ensure that appropriate antimicrobials can be administered for postoperative infection.     

Addictive behaviors in liver transplant recipients: The real problem?

Liver transplantation(LT) is the gold standard treatment for end-stage liver disease. Whatever the primary indication of LT, substance abuse after surgery may decrease survival rates and quality of life. Prevalence of severe alcohol relapse is between 11 and 26%,and reduces life expectancy regardless of the primary indication of LT. Many patients on waiting lists for LT are smokers and this is a major risk factor for both malignant tumors and cardiovascular events post-surgery. The aim of this review is to describe psychoactive substance consumption after LT, and to assess the impact on liver transplant recipients. This review describes data about alcohol and illicit drug use by transplant recipients and suggests guidelines for behavior management after surgery. The presence of an addiction specialist in a LT team seems to be very important.     

Risk factors for infection after liver transplantation

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

Prevalence, incidence and correlates of HHV-8/KSHV infection and Kaposi's sarcoma in renal and liver transplant recipients.

BACKGROUND: To determine whether the incidence of HHV-8/KSHV infection and the risk of developing KS among organ transplant recipients differ by type of organ transplanted, we calculated the rate of HHV-8/KSHV seroconversion and the risk of developing KS among renal and liver transplant recipients. METHODS: The study population consisted of renal and liver transplant recipients recruited in two transplant centres in Rome, Italy. Both pre-transplant and post-transplant serum samples were available for all participants. The prevalence of HHV-8/KSHV infection before transplantation was calculated. To determine risk factors for infection, we calculated ORs and 95% CI. Seroconversion rates (i.e. attack rates) after transplantation were also calculated. Differences in attack rates were calculated using a binomial test for proportions. RESULTS: Of the 130 participants, 21 (16.1%) were HHV-8/KSHV-positive before transplantation. Women were more likely to be infected than men, whereas no difference was observed by type of organ transplanted. Of the 109 initially negative individuals, 13 (11.9%) developed anti-HHV-8/KSHV antibodies after transplantation. The incidence of HHV-8/KSHV infection tended to be higher among liver transplant recipients. Four renal transplant recipients and none of the liver transplant recipients developed KS after transplantation. The risk of KS was higher among recipients who were already HHV-8/KSHV-positive before transplantation. CONCLUSIONS: HHV-8/KSHV seroconversion rates appear to be higher among liver transplant recipients, compared to renal transplant recipients. However, renal transplant recipients tend to have a higher risk of KS. HHV-8/KSHV reactivation appears to play a greater role on the risk of KS than incident infections.