Lower respiratory tract viral infections in pediatric abdominal organ transplant recipients: a single hospital inpatient cohort study

One-year Incidence of Infection in Pediatric Intestine Transplantation

BACKGROUND

This study reports the infection rate, location of infection and pathogen causing bacterial, fungal or viral infections in intestine transplant recipients at a pediatric transplant center.

METHODS

Records from a pediatric center were reviewed for patients receiving an intestine transplant. Positive cultures and pathology reports were used to diagnose bacterial, fungal and viral infections and also to determine location and infectious agent. Risk for infection was assessed based on liver or colon inclusion, and immunosuppression induction, as part of the intestine transplant.

RESULTS

During the study period, 52 intestine transplants were performed on 46 patients. Bacterial, fungal and viral infection rates were 90%, 25% and 75%, respectively. Enterococcus spp. (non-vancomycin-resistant enterococci) were the most common pathogens and were isolated from 52% of patients. Non-vancomycin-resistant enterococci was present in 12% of transplant recipients. Candida spp. were the most common fungal pathogens (23% of patients). Respiratory viral infections were common (44%), and Cytomegalovirus infection rate was 17%. Common sites of infection were bloodstream, urinary and upper respiratory tract. Colon and liver inclusion in the transplant graft was not associated with increased risk of infection, nor was addition of rituximab to the immunosuppression induction protocol.

CONCLUSIONS

Postintestine transplant infections are ubiquitous in the pediatric population, including high rates of infection from bacterial, viral and fungal sources. Inclusion of the liver and/or colon as a component of the transplant graft did not appear to greatly impact the infectious risk. Adding rituximab to the immunosuppression induction protocol did not impact on infectious risk.

Respiratory syncytial virus is an "opportunistic" killer

Respiratory syncytial virus (RSV), responsible for more than three million yearly hospitalizations and up to 118 000 deaths in children under 5 years, is the leading pulmonary cause of death for this age group that lacks a licensed vaccine. Ninety-nine percent of deaths due to the virus occur in developing countries. In-hospital RSV fatalities affect previously healthy term infants in association with bacterial sepsis, clinically significant pneumothoraxes and, to a lesser extent, comorbid conditions. Community deaths affect low-income children from socially vulnerable families and appear to be as frequent as inpatient fatalities. In industrialized countries, RSV deaths occur almost exclusively in children with premorbid conditions. In a sense, RSV is an "opportunistic" killer. It needs a synergistic premorbid, medical practice-related, infectious, or social co-factor to cause a fatal outcome. But while the complex problems associated with these co-factors await solutions, candidate vaccines, long-lived monoclonal antibodies and antivirals against RSV are under clinical evaluation. It seems reasonable to predict that the landscape of RSV infections will look different in the next decade.

A Multicenter Consortium to Define the Epidemiology and Outcomes of Pediatric Solid Organ Transplant Recipients With Inpatient Respiratory Virus Infection

BACKGROUND

Respiratory virus infection (RVI) in pediatric solid organ transplant (SOT) recipients poses a significant risk; however, the epidemiology and effects of an RVI after pediatric SOT in the era of current molecular diagnostic assays are unclear.

METHODS

A retrospective observational cohort of pediatric SOT recipients (January 2010 to June 2013) was assembled from 9 US pediatric transplant centers. Charts were reviewed for RVI events associated with hospitalization within 1 year after the transplant. An RVI diagnosis required respiratory symptoms and detection of a virus (ie, human rhinovirus/enterovirus, human metapneumovirus, influenza virus, parainfluenza virus, coronavirus, and/or respiratory syncytial virus). The incidence of RVI was calculated, and the association of baseline SOT factors with subsequent pulmonary complications and death was assessed.

RESULTS

Of 1096 pediatric SOT recipients (448 liver, 289 kidney, 251 heart, 66 lung, 42 intestine/multivisceral), 159 (14.5%) developed RVI associated with hospitalization within 12 months after their transplant. RVI occurred at the highest rates in intestine/abdominal multivisceral (38%), thoracic (heart/lung) (18.6%), and liver (15.6%) transplant recipients and a lower rate in kidney (5.5%) transplant recipients. RVI was associated with younger median age at transplant (1.72 vs 7.89 years; P < .001) and among liver or kidney transplant recipients with the receipt of a deceased-donor graft compared to a living donor (P = .01). The all-cause and attributable case-fatality rates within 3 months of RVI onset were 4% and 0%, respectively. Multivariable logistic regression models revealed that age was independently associated with increased risk for a pulmonary complication (odds ratio, 1.24 [95% confidence interval, 1.02-1.51]) and that receipt of an intestine/multivisceral transplant was associated with increased risk of all-cause death (odds ratio, 24.54 [95% confidence interval, 1.69-327.96]).

CONCLUSIONS

In this study, hospital-associated RVI was common in the first year after pediatric SOT and associated with younger age at transplant. All-cause death after RVI was rare, and no definitive attributable death occurred.

Burden of Healthcare-Associated Viral Respiratory Infections in Children's Hospitals

OBJECTIVE

Although healthcare-associated (HA) viral respiratory infections (VRIs) are common in pediatrics, no benchmark for comparison exists. We aimed to determine, compare, and assess determinants of unit-specific HA-VRI incidence rates in 2 children's hospitals.

METHODS

This study was a retrospective comparison of prospective cohorts. The Montreal Children's Hospital and the Cohen Children's Medical Center of New York perform prospective surveillance for HA-VRI using standardized definitions that require the presence of symptoms compatible with VRI and virus detection. Cases detected between April 1, 2010, and March 31, 2013, were identified using surveillance databases. Annual incidence rates were calculated, and a generalized estimating equation model was used to assess determinants of HA-VRI rates.

RESULTS

The overall HA-VRI rate during the 3-year study period was significantly higher at Montreal Children's Hospital than that at Cohen Children's Medical Center of New York (1.91 vs 0.80 per 1000 patient-days, respectively; P < .0001). Overall, the HA-VRI incidence rate was lowest in the neonatal intensive care unit. Rates in the pediatric intensive care, oncology, and medical/surgical units were similar. The most common etiology of HA-VRI at both institutions was rhinovirus (49% of cases), followed by parainfluenza virus and respiratory syncytial virus. Hospitals with less than 50% single rooms had HA-VRI rates 1.33 (95% confidence interval, 1.29-1.37) times higher than hospitals with more than 50% single rooms for a given unit type.

CONCLUSIONS

HA-VRI rates were substantial but different among 2 children's hospitals. Future studies should examine the effect of HA-VRI and evaluate best practices for preventing such infections.

Defining the Incidence and Associated Morbidity and Mortality of Severe Respiratory Syncytial Virus Infection Among Children with Chronic Diseases

INTRODUCTION

REGAL (RSV Evidence-a Geographical Archive of the Literature) has provided a comprehensive review of the published evidence in the field of respiratory syncytial virus (RSV) in Western countries over the last 20 years. This review covers the risk and burden of RSV infection in children with underlying medical conditions or chronic diseases (excluding prematurity and congenital heart disease).

METHODS

A systematic review of publications between January 1, 1995 and December 31, 2015 across PubMed, Embase, The Cochrane Library, and Clinicaltrials.gov was supplemented by papers identified by the authors through March 2017. Studies reporting data for hospital visits/admissions for RSV infection as well as studies reporting RSV-associated morbidity and mortality were included. Study quality and strength of evidence (SOE) were graded.

RESULTS

A total of 2703 studies were identified and 58 were included. Down syndrome, irrespective of prematurity and congenital heart disease (moderate SOE), immunocompromised children (low SOE), cystic fibrosis (low SOE), and neurologic conditions (low SOE) were associated with a significantly increased risk of RSV hospitalization. A number of other congenital malformations and chronic conditions were also associated with severe RSV disease (low SOE). In general, pre-existing disease was also a predisposing factor for RSV-related mortality (low SOE).

CONCLUSION

Severe RSV infection in infants and young children with underlying medical conditions or chronic diseases poses a significant health burden. Further studies are needed to fully quantify the epidemiology, burden and outcomes in these populations, in particular RSV-attributable mortality.

Update in the treatment of non-influenza respiratory virus infection in solid organ transplant recipients

INTRODUCTION

Despite the improved outcomes in solid organ transplantation with regard to prevention of rejection and increased patient and graft survival, infection remains a common cause of morbidity and mortality. Respiratory viruses are a frequent and potentially serious cause of infection after solid organ transplantation. Furthermore, clinical manifestations of respiratory virus infection (RVI) may be more severe and unusual in solid organ transplant recipients (SOTRs) compared with the non-immunocompromised population. Areas covered: This article reviews the non-influenza RVIs that are commonly encountered in SOTRs. Epidemiologic and clinical characteristics are highlighted and available treatment options are discussed. Expert opinion: New diagnostic tools, particularly rapid molecular assays, have expanded the ability to identify specific RVI pathogens in SOTRs. This is not only useful from a treatment standpoint but also to guide infection control practices. More data are needed on RVIs in the solid organ transplant population, particularly regarding their effect on rejection and graft dysfunction. There is also a need for new antiviral agents active against these infections as well as markers that can identify which patients would most benefit from treatment.

Clinical outcomes in outpatient respiratory syncytial virus infection in immunocompromised children

Background

Immunocompromised patients are at high risk for morbidity and mortality due to respiratory syncytial virus (RSV) infection. Increasingly, pediatric patients with malignancy or undergoing transplantation are managed primarily as outpatients. Data regarding the clinical presentation and outcomes of RSV in the outpatient pediatric immunocompromised population are limited.

Methods

We performed a retrospective cohort study of children with hematologic malignancy or hematopoietic or solid organ transplant with laboratory‐confirmed RSV infection diagnosed as outpatients at an academic medical center between 2008 and 2013.

Results

Of 54 patients with RSV detected while outpatients, 15 (28%) were hospitalized, 7 (13%) received ribavirin, and one (2%) received intravenous immunoglobulin. One (2%) patient was critically ill, but there were no deaths due to RSV infection. Fever (P < 0·01) was associated with increased risk of hospitalization.

Conclusions

Most immunocompromised children with RSV detected while outpatients did not require hospitalization or receive antiviral treatment. Potential studies of RSV therapies should consider inclusion of patients in an ambulatory setting.

Infection Prevention and Control Issues After Solid Organ Transplantation

Infections are an important cause of morbidity and mortality in solid organ transplant recipients. Consequently, infection prevention is an essential component of any organ transplant program. Given their frequent and often prolonged contact with the healthcare system, solid organ transplant recipients are at high risk for healthcare-associated infections, including those caused by antibiotic-resistant organisms. In this chapter we review several different healthcare-associated infections of importance to transplant recipients, including those caused by bacterial, viral, and fungal organisms. We also describe infection prevention and control strategies applicable to this patient population. These practices focus on clinical interventions and environmental controls designed to prevent the spread of potentially pathogenic organisms in the healthcare setting. We also describe post-exposure interventions applicable to solid organ transplant recipients exposed to potential pathogens in order to reduce their risk of subsequent infection.

Risks and Epidemiology of Infections After Intestinal Transplantation

Intestinal transplantation has become a well-accepted and successful procedure to save the lives of patients suffering from intestinal failure and who have developed life-threatening complications of parenteral nutrition. Advances in all aspects of care, from the role of multidisciplinary intestinal rehabilitation services prior to transplant to the development strategies for early recognition of infectious sequelae and even the increasing availability of preventive strategies, have led to improved outcomes and a dramatic decline in infection-associated morbidity and mortality in children undergoing intestinal transplantation. Improvements in surgical techniques and immunosuppressive regimens have been essential components in these improvements, reducing risk of infection through reduction of technical complications and more optimal immunosuppression regimens. In addition, the development of molecular tools for early recognition of viral pathogens and an understanding of the timing and risks for infection have allowed for earlier and more successful treatments. Despite these improvements, infectious sequelae remain an important problem in this population, and additional efforts are needed to further minimize the risk of infectious sequelae in those children requiring this procedure.

Medical management of children after liver transplantation

PURPOSE OF REVIEW

Successful outcomes in patient, graft survival, and quality of life depend on the prevention, early detection, and treatment of possible complications. The aim of the study was to highlight the common outcomes focusing on the unique features in children. Medical follow-up of children after liver transplantation includes monitoring of surgical complications: biliary and vascular, rejection, infections, posttransplant lymphoproliferative disease, other malignancies, recurrent disease, graft function, hypertension, diabetes, renal failure, among other conditions. The goal is to maintain normal graft function on minimal immunosuppression to avoid medication-induced side-effects.

RECENT FINDINGS

Recent findings include the importance of meticulous follow-up of Epstein-Barr virus and Cytomegalic virus viral load, leading to early diagnosis and improved prognosis, increased prevalence of renal toxicity, cognitive dysfunction, autoimmune, atopic and eosinophilic disease, oral hygiene and chronic hepatitis, and fibrosis of allografts.

SUMMARY

Caring for children after liver transplantation is extremely rewarding; however, careful attention must be paid to a variety of systems with understanding of the distinctiveness of pediatrics to assure optimal outcomes.

First report of severe parainfluenza virus 4B and rhinovirus C coinfection in a liver transplant recipient treated with immunoglobulin

We describe the first reported case of severe pneumonia due to coinfection by parainfluenza virus type 4B and rhinovirus C in a liver transplant recipient. The patient responded promptly to intravenous immunoglobulin and timely infection control measures prevented spreading of the infections. This report highlights respiratory viral coinfections as a possible cause of severe morbidity in transplant recipients and the importance of efficient molecular diagnostic technologies with major impact on clinical practice in a transplant center. It also describes a potential therapeutic strategy for such patients.

Lower respiratory tract viral infections in pediatric abdominal organ transplant recipients: a single hospital inpatient cohort study

Respiratory viral infections are a major cause of morbidity and mortality in solid organ transplant recipients. Early detection of a viral etiology of a LRTI in a febrile transplant recipient can theoretically reduce the use of antibiotics, trigger modification of immunosuppression and prompt appropriate isolation procedures to reduce nosocomial infections. We retrospectively evaluated pediatric abdominal organ transplant recipients hospitalized with respiratory illnesses to determine the viral pathogens identified by various methods including multiplex RT-PCR performed on nasopharyngeal or endotracheal aspirates. Among 30 symptomatic subjects (median age, 2.5 yr) evaluated using this methodology, 25 (83%) were positive for at least one virus. Rhinovirus was the most frequently identified virus (14 subjects). RSV was identified in five subjects with associated mortality of 40%. Parainfluenza, influenza, metapneumovirus, and adenovirus were also identified. This study indicates that rhinovirus is a significant cause of morbidity in this single center cohort of pediatric abdominal organ transplant recipients.