Clinical and microbiological epidemiology of early and late infectious complications among solid-organ transplant recipients requiring hospitalization

Investigating infectious outcomes in adult patients undergoing solid organ transplantation: A retrospective single-center experience, Paris, France

OBJECTIVES

This study described the demographic characteristics, clinical presentation, treatment, and outcomes of solid organ transplant recipients who were admitted to our center for infection. It also determined factors associated with a poor outcome, and compares early and late period infections.

METHODS

In this retrospective observational study, conducted at a tertiary care center in France between October 2017 and March 2019, infectious outcomes of patients with solid organ transplant where studied.

RESULTS

A total of 104 patients were included with 158 hospitalizations for infection. Among these 104 patients, 71 (68%) were men. The median age was 59 years old. The most common symptoms on admission were fever (66%) and chills (31%). Lower respiratory tract infections were the most common diagnosis (71/158 hospitalizations). Urinary tract infections were frequently seen in kidney transplant recipients (25/60 hospitalizations). One or more infectious agents were isolated for 113 hospitalizations (72%): 70 bacteria, 36 viruses and 10 fungi, with predominance of gram-negative bacilli (53 cases) of which 13 were multidrug-resistant. The most frequently used antibiotics were third generation cephalosporins (40 cases), followed by piperacillin-tazobactam (26 cases). We note that 25 infections (16%) occurred during the first 6 months (early post-transplant period). Patients admitted during the early post-transplant period were more often on immunosuppressive treatment with prednisone (25/25 VS 106/133) (p = 0.01), mycophenolic acid (22/25 VS 86/133) (p = 0.03), presented for an urinary tract infection (10/25 VS 25/133) (p = 0.04) or a bacterial infection (17/25 VS 53/133) (p = 0.01). Patients with later infection had more comorbidities (57/83 VS 9/21) (p = 0.03), cancer (19/83 VS 0/21) (p = 0.04) or were on treatment with everolimus (46/133 VS 0/25) (p = 0.001). During 31 hospitalizations (20%), patients presented with a serious infection requiring intensive care (n = 26; 16%) or leading to death (n = 7; 4%). Bacteremia, pulmonary and cardiac complications were the main risk factors associated with poor outcome.

CONCLUSION

Infections pose a significant challenge in the care of solid organ transplant patients, particularly those with comorbidities and intensive immunosuppression. This underscores the crucial importance of continuous surveillance and epidemiologic monitoring within this patient population.

Evaluation of donor-derived bacterial infections in lung transplant recipients

Background

This study aims to evaluate the etiology and outcomes of donor-derived bacterial infections in patients undergoing lung transplantation.

Methods

Between January 2013 and December 2017, a total of 71 lung transplant recipients (56 males, 15 females; median age: 43.3 years) were retrospectively analyzed. The diagnosis of donor-derived bacterial infection was defined as the isolation of the same bacteria with the same antibiotic susceptibility patterns in a lung sample of donor and in one sample obtained from patients after transplantation and the presence of clinical evidence of infection.

Results

Ten (14%) patients were found to have donor-derived bacterial infection. Acinetobacter baumannii was found in three, Pseudomonas aeruginosa in three, Klebsiella pneumoniae in one, Enterobacter cloacae in one, Staphylococcus aureus in one, and both Klebsiella pneumoniae and Acinetobacter baumannii in one patient. Twenty-four of lung-transplant recipients and four patients with donor-derived infection died.

Conclusion

Lung transplants are usually performed in hospitalized patients or in those admitted to the intensive care unit. These patients commonly experience infection and colonization with resistant microorganisms.

Multidrug-resistant organisms: A significant cause of severe sepsis in pediatric intestinal and multi-visceral transplantation

Severe sepsis in immunocompromised children is associated with increased mortality. This paper describes the epidemiology landscape, clinical acuity, and outcomes for severe sepsis in pediatric intestinal (ITx) and multi-visceral (MVTx) transplant recipients requiring admission to the pediatric intensive care unit (PICU). Severe sepsis episodes were retrospectively reviewed in 51 ITx and MVTx patients receiving organs between 2009 and 2015. Twenty-nine (56.8%) patients had at least one sepsis episode (total of 63 episodes) through December 2016. Bacterial etiologies accounted for 66.7% of all episodes (n = 42), occurring a median of 122.5 days following transplant (IQR 59-211.8 days). Multidrug-resistant organisms (MDROs) accounted for 73.8% of bacterial infections; extended spectrum beta-lactamase producers, vancomycin-resistant enterococcus, and highly-resistant Pseudomonas aeruginosa were the most commonly identified. Increased mechanical ventilation and vasoactive requirements were noted in MDRO episodes (OR 3.03, 95% CI 1.09-8.46 and OR 3.07, 95% CI 1.09-8.61, respectively; p < .05) compared to non-MDRO episodes. PICU length of stay was significantly increased for MDRO episodes (7 vs. 3 days, p = .02). Graft loss was 24.1% (n = 7) and mortality was 24.1% (n = 7) in patients who experienced severe sepsis. Further attention is needed for MDRO risk mitigation and modification of sepsis treatment guidelines to ensure MDRO coverage for this population.

Safety of biologic treatments in solid organ transplant recipients: A systematic review

BACKGROUND

The development of biological treatments has transformed the management of a broad spectrum of autoimmune/inflammatory diseases. However, little is known about their use in solid-organ transplant recipients. This study aimed to evaluate complications occurring with biologic treatments in solid-organ transplant recipients.

METHODS

A systematic review of the literature was performed in the Medline, Embase and Cochrane databases, up to 01/10/2020, to identify published case reports or series reporting the use of biologic treatments in solid organ transplant recipients with chronic inflammatory diseases. We collected data on patient characteristics and reported complications.

RESULTS

In total, 57 articles were included, totalling 187 patients (141 liver, 42 kidney, 3 heart, and 1 liver-kidney transplant recipients). Inflammatory bowel diseases represented the most common indication for biologic treatment initiation (80.7%), followed by rheumatic diseases (7.5%), hereditary periodic fever syndromes (5.9%) and psoriasis (4.8%). Anti-TNFα were mainly used (77.5%; mainly monoclonal antibodies (70%) compared to soluble receptor etanercept (7.5%)), followed by the anti-α4β7 integrin, vedolizumab (27.3%) and the anti-IL-1R, anakinra (6.9%). Median treatment duration was 12 months. Infections occurred in 54 patients (28.9%) through 88 recorded events. No therapeutic or demographic factors were associated with occurrence of infection. Sixteen patients (8.6%) developed malignancies, and acute graft rejections occurred in 5 patients (2.7%). Among the 187 patients, 9 deaths were reported (4.8%).

CONCLUSIONS

This review assembles the largest number of published reports regarding the use of biological treatments in solid organ transplant recipients, providing data about their safety. Further comparative studies are needed to assess the safety of biological treatments in transplanted patients.

Molecular characterization of multidrug resistant Enterobacterales strains isolated from liver and kidney transplant recipients in Spain

The objective of this study was to analyse the mechanisms of resistance to carbapenems and other extended-spectrum-β-lactams and to determine the genetic relatedness of multidrug-resistant Enterobacterales (MDR-E) causing colonization or infection in solid-organ transplantation (SOT) recipients. Prospective cohort study in kidney (n = 142), liver (n = 98) or kidney/pancreas (n = 7) transplant recipients between 2014 and 2018 in seven Spanish hospitals. We included 531 MDR-E isolates from rectal swabs obtained before transplantation and weekly for 4–6 weeks after the procedure and 10 MDR-E from clinical samples related to an infection. Overall, 46.2% Escherichia coli, 35.3% Klebsiella pneumoniae, 6.5% Enterobacter cloacae, 6.3% Citrobacter freundii and 5.7% other species were isolated. The number of patients with MDR-E colonization post-transplantation (176; 71.3%) was 2.5-fold the number of patients colonized pre-transplantation (71; 28.7%). Extended-spectrum β-lactamases (ESBLs) and carbapenemases were detected in 78.0% and 21.1% of MDR-E isolates respectively. In nine of the 247 (3.6%) transplant patients, the microorganism causing an infection was the same strain previously cultured from surveillance rectal swabs. In our study we have observed a low rate of MDR-E infection in colonized patients 4–6 weeks post-transplantation. E. coli producing bla_CTX-M-G1 and K. pneumoniae harbouring bla_OXA-48 alone or with bla_CTX-M-G1 were the most prevalent MDR-E colonization strains in SOT recipients.

Fungal endocarditis in transplant recipients: A systematic review

BACKGROUND

Invasive fungal infections remain a major cause of morbidity and mortality in transplant recipients. Moreover, Fungal Infective Endocarditis (FIE) is a rare infection that carries a higher mortality than bacterial IE in normal host, while in transplant recipients may be even higher. The purpose of this study was to systemically review all published cases of FIE in solid organ and allogeneic bone marrow transplant recipients, describe the epidemiology, microbiology, clinical characteristics, treatment and outcomes of these infections, and to identify risk factors for mortality by FIE.

METHODS

A systematic review of PubMed, Scopus and Cochrane Library (through 20 May 2020) for studies providing epidemiological, clinical, microbiological and treatment data and outcomes of FIE in transplant recipients was performed.

RESULTS

A total of 60 studies, containing data of 72 patients, were included. The most common transplants were those of the kidney and the liver, while the commonest causative pathogen was Aspergillus. Mitral valve was the commonest infected intracardiac site, followed by mural endocardium. Diagnosis was made with transthoracic echocardiography in 44.3%, while the diagnosis was made at autopsy in 37.3%. Embolic phenomena were the commonest clinical presentation, followed by fever, heart failure and endophthalmitis. Amphotericin B, voriconazole and caspofungin were the commonest antifungals used for treatment of FIE. Clinical cure was noted in 26.9%, while overall mortality was 78.6%. Amphotericin B or caspofungin use was negatively associated with overall mortality.

CONCLUSIONS

This systematic review thoroughly describes IE in transplant recipients and provides information on epidemiology, clinical presentation, treatment and outcomes.

Infection is the chief cause of mortality and non-death censored graft loss in the first year after renal transplantation in a resource limited population: A single centre study

AIM

Few studies have assessed the impact of infections after renal transplantation (RTX) in low and middle income countries. This single centre study aimed to delineate the profile and impact of infections requiring hospitalization (IRH) occurring in the first year after RTX in India.

METHOD

Patients who underwent RTX between July 2012 and June 2015 were followed up for 12 months after transplantation.

RESULTS

60.2% of the 387 patients studied had at least one IRH and total 492 infections were diagnosed. The most common were urinary tract (30.3%), gastrointestinal (17.1%) and pulmonary (11.2%) infections. Viral aetiology (33.3%) was most frequent, followed by bacterial (23.6%), parasitic (5.1%), tuberculosis (4.5%), and fungal infections (3.9%). 86.4% deaths were due to infections. One year patient and graft survival were inferior among recipients with IRH compared to those with no IRH: 91.8% vs. 98.1% (log rank = 0.010) and 90.1% vs. 97.4% (log rank = 0.006) respectively. Average monthly income per family member <5000 Rupees (75 USD), NODAT, and acute rejection were independent risk factors for IRH.

CONCLUSION

The profile of IRH is unique involving opportunistic, community-acquired and endemic infections seen in this country. It is the predominant cause of mortality and graft loss in the first year after RTX. Poor economic status is an important determinant of IRH in our population.

Antimicrobial stewardship by academic detailing improves antimicrobial prescribing in solid organ transplant patients

We implemented twice-weekly academic detailing rounds in 2015 as an antimicrobial stewardship (AMS) intervention in solid organ transplant (SOT) patients, led by an AMS pharmacist and a transplant infectious diseases physician. They reviewed SOT patients' antimicrobials and made recommendations to prescribers on antimicrobial regimens, diagnostics investigations, and appropriate referrals for transplant infectious diseases consultation. To determine the impact of the intervention, we adjudicated antimicrobials prescriptions using established AMS principles, and compared the proportion of AMS-concordance regimens pre-intervention (2013) with post-intervention (2016) via 4-point-prevalence surveys conducted in each period. All admitted SOT patients who were receiving antimicrobial treatment on survey days were included. Primary outcome was the percentage of antimicrobial regimen adjudicated as AMS concordant. Secondary outcomes were percentage of AMS concordance in patients consulted by transplant infectious diseases; categories of AMS discordance; antimicrobial consumption in defined daily dose/100 patient-days (DDD/100PD); antimicrobial cost in CAD$/PD; and C. difficile infections. Balancing measures were length of stay, 30-day readmission, and in-hospital mortality. We compared outcomes using χ² test or t-test; significant difference was defined as p < 0.05. Pre-intervention surveys included 139 patients, post-intervention, 179 patients, with 62.3% vs. 56.6% receiving antimicrobials, respectively (p = 0.27). AMS concordance increased from 69% (60/87) to 83.7% (93/111), p = 0.01. Not tailoring antimicrobials was the most common discordance category. AMS concordance under transplant infectious diseases was 82.5% (33/40) pre-intervention vs. 76.6% (36/47) post-intervention, p = 0.5. Antimicrobial consumption increased by 15.3% (140.9 vs.162.4 DDD/100PD, p = 0.001). Antimicrobial cost, C. difficile infection rates and balancing measures remained stable. Academic detailing increased appropriate antimicrobial use in SOT patients without untoward effects.

A survey of infection prevention and control practices among solid organ transplantation centers

There are no standard guidelines for infection prevention and control practices among solid organ transplantation centers. To characterize the differences in infection prevention and control strategies, an electronic survey was performed in 2015 among members of American Society of Transplantation Infectious Diseases Community of Practice. These results highlight notable practice differences.

Infections in Liver Transplantation

Liver transplantation has become an important treatment modality for patients with end-stage liver disease/cirrhosis, acute liver failure, and hepatocellular carcinoma. Although surgical techniques and immunosuppressive regimens for liver transplantation have improved significantly over the past 20 years, infectious complications continue to contribute to the morbidity and mortality in this patient population. The use of standardized screening protocols for both donors and recipients, coupled with targeted prophylaxis against specific pathogens, has helped to mitigate the risk of infection in liver transplant recipients. Patients with chronic liver disease and cirrhosis have immunological deficits that place them at increased risk for infection while awaiting liver transplantation. The patient undergoing liver transplantation is prone to develop healthcare-acquired infections due to multidrug-resistant organisms that could potentially affect patient outcomes after transplantation. The complex nature of liver transplant surgery that involves multiple vascular and hepatobiliary anastomoses further increases the risk of infection after liver transplantation. During the early post-transplantation period, healthcare-acquired bacterial and fungal infections are the most common types of infection encountered in liver transplant recipients. The period of maximal immunosuppression that occurs at 1–6 months after transplantation can be complicated by opportunistic infections due to both primary infection and reactivation of latent infection. Severe community-acquired infections can complicate the course of liver transplantation beyond 12 months after transplant surgery. This chapter provides an overview of liver transplantation including indications, donor-recipient selection criteria, surgical procedures, and immunosuppressive therapies. A focus on infections in patients with chronic liver disease/cirrhosis and an overview of the specific infectious complications in liver transplant recipients are presented.

Predictors of postoperative infectious complications in liver transplant recipients: experience of 185 consecutive cases

BACKGROUND/AIMS

Infections following liver transplant (LT) remain a major cause of mortality. This study was conducted to evaluate risk factors for infection and to review clinical characteristics.

METHODS

Medical records of patients who underwent LT from 2010 to 2014 were retrospectively analyzed. Binary logistic regression analysis was used to investigate risk factors of infection. Kaplan-Meier analysis was used to predict prognosis of infected and non-infected groups.

RESULTS

Of 185 recipients, 89 patients experienced infectious complications. The median follow-up period was 911 days (range, 9 to 2,031). The infected group had higher 1-year mortality (n = 22 [24.7%] vs. n = 8, [8.3%], p = 0.002), and longer postoperative admission days (mean: 53.7 ± 35.8 days vs. 28.3 ± 13.0 days, p &lt; 0.001), compared to the non-infected group. High preoperative Model for End-Stage Liver Disease (MELD) score (odds ratio [OR], 1.057; 95% confidence interval [CI], 1.010 to 1.105; p = 0.016), deceased-donor type (OR, 5.475; 95% CI, 2.442 to 12.279; p &lt; 0.001), and acute rejection (OR, 3.042; 95% CI, 1.241 to 7.454; p = 0.015) were independent risk factors associated with infection. Intra-abdominal infection (n = 35, 20.8%) was the major infectious complication. Among identified bacteria, Enterococcus species (28.4%) were major pathogens, followed by Escherichia coli and Klebsiella species.

CONCLUSIONS

High preoperative MELD score, deceased-donor type, and acute rejection were risk factors associated with infection. To prevent infections following surgery, it is important to determine the appropriate time of operation before the recipient has a high MELD score.

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

Introduction

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

Material and methods

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

Results

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

Conclusions

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

Infections in liver and lung transplant recipients: a national prospective cohort

Infections are a major complication of solid organ transplants (SOTs). This study aimed to describe recipients' characteristics, and the frequency and etiology of infections and transplant outcome in liver and lung SOTs, and to investigate exposures associated to infection and death in liver transplant recipients. The study population included recipients of SOTs performed in Italy during a 1-year period in ten Italian lung transplant units and eight liver transplant units. Data on comorbidities, infections, retransplantation, and death were prospectively collected using a web-based system, with a 6-month follow-up. The cumulative incidence of infection was 31.7% and 47.8% in liver and lung transplants, respectively, with most infections occurring within the first month after transplantation. Gram-negatives, which were primarily multidrug-resistant, were the most frequent cause of infection. Death rates were 0.42 per 1000 recipient-days in liver transplants and 1.41 per 1000 recipient-days in lung transplants. Infection after SOT in adult liver recipients is associated to an increased risk of death (OR = 13.25; p-value < 0.001). Given the frequency of infection caused by multidrug-resistant microorganisms in SOT recipients in Italy and the heavy impact of infections on the transplant outcome, the reinforcement of surveillance and control activities to prevent the transmission of multidrug-resistant microorganisms in SOT recipients represents a priority. The implementation of the study protocol in liver and lung transplant units and the sharing of results have increased the awareness about the threat due to antimicrobial resistance in the country.

Infections in pediatric solid-organ transplant recipients

Solid-organ transplantation in pediatrics can be a life-saving procedure, but it cannot be accomplished without risk of infection-related morbidity and mortality. Evaluation of the recipient during candidacy and donor during evaluation can assist with identification of risk. Further, risk of infection from the surgical procedure can be mitigated through careful planning and attention to infection prevention processes. Finally, early recognition of infection posttransplant can limit the impact of these events.

Effect of underlying immune compromise on the manifestations and outcomes of group A streptococcal bacteremia

BACKGROUND

Group A streptococcal bloodstream infection is the most common presentation of invasive group A streptococcal disease. We sought to determine the impact of immunosuppression on severity of disease and clinical outcomes.

METHODS

This retrospective review of 148 patients with at least one positive blood culture for Streptococcus pyogenes from 1/2003 to 3/2013 compared immunocompromised patients with those with no immunocompromise in regards to development of severe complications and mortality.

RESULTS

Twenty-five patients (17%) were immunocompromised; 123 were not. Skin and soft tissue infection occurred in 60% of immunocompromised vs. 38% of non-immunocompromised patients, p = .04. Necrotizing fasciitis and septic shock were significantly more common in immunocompromised patients, p < .0001 and .028, respectively. Mortality at 30 days was 32% in immunocompromised patients vs. 16% in non-immunocompromised patients, p = .05.

CONCLUSION

Patients who are immunocompromised are more likely to develop necrotizing fasciitis and septic shock as complications of group A streptococcal bacteremia and have a higher mortality rate than patients who are not immunocompromised.