Donor-derived infections in solid organ transplant patients: toward a holistic approach

Clinical approach to donor-derived infection in solid organ transplant recipients

Donor-derived infection is an uncommon but potentially devastating complication of solid organ transplantation (SOT). Accurate and timely identification of unexpected infectious disease transmission events has implications not only for the recipient(s) experiencing infection, but also other recipients of organs or tissues from the same donor who may require additional testing or risk mitigation, as well as the broader organ transplant regulatory framework. This narrative review synthesizes data from published reports of symptomatic unexpected donor-derived infections in SOT recipients to provide clinicians with a systematic approach to the evaluation of undifferentiated illnesses that may be of donor origin. Key reasons to consider donor-derived infection include certain microbiologically proven infections in the recipient, especially early after transplant, characteristics of the donor or their management that suggest potential exposure to or infection with specific pathogens prior to organ procurement, and select clinical syndromes that occur in the post-transplant period. Syndromes for which expedited consideration and evaluation of donor-derived infection may be warranted include central nervous system infection, graft or perigraft complications developing in the absence of typical risk factors, and unexplained critical illness/sepsis syndrome in the early post-transplant period. When embarking on an investigation of a suspected donor-derived infection, clinicians should apply knowledge of the entire continuum of the organ procurement and transplant process to ensure unbiased and comprehensive data collection that will facilitate appropriate adjudication of these uncommon but high-consequence events.

Donor-derived carbapenem-resistant gram-negative bacterial infections in solid organ transplant recipients: Active surveillance enhances recipient safety

Donor-derived infections (DDIs) caused by carbapenem-resistant gram-negative bacteria (CR-GNB) in solid organ transplant recipients are potentially life-threatening. In this prospective study, we evaluated the incidence, factors associated with transmission, and the outcome of recipients with unexpected CR-GNB DDIs after the implementation of our local active surveillance system (LASS). LASS provides for early detection of unexpected donor CR-GNB infections, prophylaxis of recipients at high risk, and early diagnosis and treatment of DDIs. Whole genome sequencing confirmed DDI. Among 791 recipients, 38 (4.8%) were at high risk of unexpected CR-GNB DDI: 25 for carbapenem-resistant Enterobacterales (CRE) and 13 for carbapenem-resistant Acinetobacter baumannii (CRAB). Transmission did not occur in 27 (71%) cases, whereas DDIs occurred in 9 of 25 of CRE and 2 of 13 of CRAB cases. Incidence of CR-GNB DDI was 1.4%. Recipients of organs with CR-GNB-positive preservation fluid and liver recipients from a donor with CRE infection were at the highest risk of DDI. There was no difference in length of hospital stay or survival in patients with and without CR-GNB DDI. Our LASS contains transmission and mitigates the negative impacts of CR-GNB DDI. Under well-defined conditions, organs from donors with CR-GNB may be considered after a thorough evaluation of the risk/benefit profile.

The utilization of nanopore targeted sequencing proves to be advantageous in the identification of infections present in deceased donors

Background

Nanopore Target Sequencing (NTS) represents a novel iteration of gene sequencing technology; however, its potential utility in the detection of infection in deceased donors has yet to be documented. The present study endeavors to assess the applicability of NTS in this domain.

Methods

This retrospective study comprised a cohort of 71 patients who were under intensive care at Renmin Hospital of Wuhan University between June 2020 and January 2022. The specimens were subjected to microbiological tests utilizing NTS, culture, and other techniques, and subsequently, the diagnostic accuracy of NTS was compared with conventional methods.

Results

Blood NTS exhibited a better agreement rate of 52.11% and a greater positive rate of pathogen detection than blood culture (50.70% vs. 5.63%, p < 0.001). In NTS of deceased donors, Klebsiella pneumoniae, Escherichia coli, and Acinetobacter baumannii were the most frequently found bacteria, and Candida was the most frequently found fungus. Blood NTS had a considerably better sensitivity for detecting clinical bloodstream infection than blood culture (62.50%: 7.14%, p < 0.001). These findings were supported by comparisons between blood NTS and conventional microbial detection methods (such as blood culture, glucan testing, galactomannan testing, T cell spot testing for tuberculosis infection, smear, etc.).

Conclusion

The pathogen detection technology NTS has a high sensitivity and positive rate. It can more accurately and earlier detect infection in deceased donors, which could be very important for raising the donation conversion rate.

Balancing the Risks and Benefits of Pet Ownership in Pediatric Transplant Recipients

In recent decades, the number of pediatric transplantations and their survival rates have increased. Psychological problems and poorer quality of life are notable among children undergoing transplantation and can have long-lasting consequences and affect immunosuppressive therapy adherence. Pet ownership and animal contact have been associated with physical, mental, and social health benefits. Despite these potential benefits, however, companion animals are known to be a source of infection, which is one of the main concerns for clinicians. Because of immunosuppression, these children are particularly vulnerable to infections. Zoonoses comprise a long list of infectious diseases and represent a major public health problem. Nevertheless, many families and most healthcare providers are unaware of these potential risks, and there is a worrisome lack of recommendations to manage the risk-benefit balance, which could pose a risk for acquiring a zoonosis. Furthermore, no data are available on the number of transplanted patients with pets, and this risk-benefit balance is difficult to adequately evaluate. In this document, we review the currently available evidence regarding the epidemiology of zoonotic infections in patients undergoing transplantation, focusing on pediatric patients from a risk-benefit perspective, to help inform decision-making for clinicians. Families and healthcare professionals should be aware of the risks, and clinicians should actively screen for pets and offer comprehensive information as part of routine clinical practice. A multidisciplinary approach will ensure proper care of patients and pets and will establish preventive measures to ensure patients are safe living with their pets.

The Significance and Impact of Screening Preservation Fluid Cultures in Renal Transplant Recipients

INTRODUCTION

Infectious complications can be a major cause of morbidity and mortality in solid organ transplant recipients. Preservation fluid is necessary to maintain organ viability but may serve as a vector or infection. The utility of screening preservation fluid routinely for microbial growth and the impact of culture-positive preservation fluid is controversial. Research Question: What is the clinical impact of a culture positive preservation fluid in a kidney transplant recipient?

DESIGN

This retrospective study was performed to define the incidence of post-operative infection related to PF and examine the negative sequelae of culture-positive PF. One hundred and fifty-two deceased donor renal transplant recipients from January 2015 to December 2017 were included for analysis.

RESULTS

Overall, 67% of patients (102/152) received an allograft from a culture-positive PF. Nearly 80% of microbial growth was consistent with skin flora, and coagulase-negative staphylococci was the most frequently isolated organism (56%). Sixty-seven percent of patients (68/102) with culture-positive PF received antimicrobial treatment for an average duration of 5 days. There was no difference in the incidence of infection between patients with culture positive PF compared to culture-negative PF. Furthermore, there were no cases of infection related to PF regardless of whether culture-positive PF was treated or untreated. The incidence of subsequent C. difficile infection and multidrug-resistant organisms was similar.

DISCUSSION

This study suggests antimicrobial treatment for culture positive PF may not be necessary with pathogens that are common contaminants and of low virulence. Interventional studies are needed to validate this strategy.

Multidrug-resistant Gram-negative infection in solid organ transplant recipients: implications for outcome and treatment

PURPOSE OF REVIEW

Solid organ transplantation (SOT) is the best therapeutic option for both acute and chronic end-stage diseases. The development of more potent and safer immunosuppressants and the improvement of prophylactic practices have significantly diminished the morbidity and mortality associated with rejection and opportunistic infections. However, infections produced by multidrug-resistant (MDR) Gram-negative bacilli (GNB) have recently emerged as a significant threat.

RECENT FINDINGS

The Spanish Society of Transplantation (SET), the Group for Study of Infection in Transplantation of the Spanish Society of Infectious Diseases and Clinical Microbiology (GESITRA-SEIMC) and the Spanish Network for Research in Infectious Diseases (REIPI) have recently published their recommendations concerning the management of MDR GNB infections in SOT recipients. We review this guideline, and also the most recent available evidence, focusing on donor-derived infections, colonized recipients and therapeutic approaches.

SUMMARY

Overall, donor and recipient colonization is associated with an increased risk of infection by MDR GNB, although none of these circumstances constitutes an absolute contraindication to transplantation. SOT recipients with risk factors for MDR GNB infection should receive an empirical treatment which includes potentially active antibiotics. Targeted therapy should be adjusted according to antimicrobial susceptibility testing and severity of infection.

Incidence and Risk Factors for Systemic Infection in Deceased Donors

BACKGROUND

Organ donation shortage is the primary barrier to all organ transplantations.Infectious disease transmission through transplantation is considered controversial for organ retrieval. Donors with bacteremia and sepsis are considered controversial for organ retrieval due to potential transmission of an infectious agent to the recipient.

METHODS

We retrospectively reviewed the results of bacterial culture of the donor's blood from peripheral venous or central venous catheter, urine, and bronchial aspiration from the organ donation registries of 102 potential donors from the Ministry of Health and Tissue Transplant Coordination Center of Istanbul Region in 2015.

RESULTS

Of the 102 deceased donors included in the analysis, 24 (23.5%) had infection. The most common sites of infection were the bloodstream (41.6%) and the respiratory system (37.5%). The most common isolated pathogens of the bacterial cultures were Gram-positive bacteria (21), Gram-negative microorganisms (14), and Candida (1). The significant risk factor for infection was duration of stay at the intensive care unit (median: 5 day; 25-75%: 3-5 day) (odds ratio, 2.94; 95% confidence interval, 1.06-8.12; P < .05). The presence of infection in the donor accounted for a significant part of the reasons why the organs were not accepted for transplantation (kidneys 9%, liver 4%, heart 6%).

CONCLUSIONS

The study showed that deceased donors with prolonged stays in the intensive care unit have an increased risk for developing nosocomial infections; so there is a need for establishing and enforcing the prevention and control of infection in possible donors.

Implementation of a Strongyloides screening strategy in solid organ transplant donors and recipients

BACKGROUND

Strongyloides stercoralis infects 100 million people worldwide. Mortality rates in hyperinfection syndrome exceed 50%. Donor-derived Strongyloides infection has occurred after heart, kidney, kidney-pancreas and liver transplantation; yet, only 10% of the US organ procurement organizations currently screen donors for strongyloidiasis.

METHODS

We report a fatal case of donor-derived disseminated Strongyloides infection in a liver transplant recipient. Following this case, we implemented universal screening and treatment of donors and recipients. We reviewed our local epidemiology and outcomes after protocol implementation.

RESULTS

From a total of 355 deceased donors accepted at our center between January 2016, and March 2018, 14 (3.9%) had positive Strongyloides serology. Except for the index case, all other recipients of Strongyloides antibody-positive donors within that period (including 10 kidneys, 3 livers, one combined liver/kidney, and one kidney/pancreas from eight seropositive donors) received post-transplant prophylaxis with ivermectin, and to date are alive and doing well without signs of infection. Between October 2015, and September 2016, a total of 441 deceased donor solid organ transplants were performed at our center. 220 of these recipients had pretransplant Strongyloides serology available, and 23 of them were seropositive (10.5%). Within the first two years after the implementation of universal screening and treatment of donors and recipients, we had no cases of Strongyloides reactivation in our center.

CONCLUSIONS

Implementation of a Strongyloides screening and treatment protocol in our center was an effective strategy to prevent both recipient- and donor-derived strongyloidiasis. Transplant centers should consider implementation of Strongyloides preventive strategies.

Emerging arboviruses and implications for pediatric transplantation: A review

Recent years have brought a rise in newly emergent viral infections, primarily in the form of previously known arthropod-transmitted viruses that have increased significantly in both incidence and geographical range. Of particular note are DENV, CHIKV, and ZIKV, which are transmitted mostly by Aedes species of mosquitoes that exhibit a wide and increasing global distribution. Being important pathogens for the general population, these viruses have the potential to be devastating in the international transplant community, with graft rejection and death as possible outcomes of infection. In this review, we discuss the current state of knowledge for these viruses as well as repercussions of infection in the solid organ and HSCT population, with a focus, when possible, on pediatric patients.