An outbreak of respiratory syncytial virus in a bone marrow transplant center

Respiratory Syncytial Virus Infections in Recipients of Bone Marrow Transplants: A Systematic Review and Meta-Analysis

Human Respiratory Syncytial Virus (RSV) is a common cause of respiratory tract infections. Usually associated with infants and children, an increasing amount of evidence suggests that RSV can cause substantial morbidity and mortality in immunocompromised individuals, including recipients of bone marrow transplantation (BMT). The present systematic review was therefore designed in accordance with the PRISMA guidelines to collect available evidence about RSV infections in BMT recipients. Three medical databases (PubMed, Embase, and MedRxiv) were therefore searched for eligible observational studies published up to 30 September 2023 and collected cases were pooled in a random-effects model. Heterogeneity was assessed using I2 statistics. Reporting bias was assessed by means of funnel plots and regression analysis. Overall, 30 studies were retrieved, including 20,067 BMT cases and 821 RSV infection episodes. Of them, 351 were lower respiratory tract infections, and a total of 78 RSV-related deaths were collected. A pooled attack rate of 5.40% (95% confidence interval [95%CI] 3.81 to 7.60) was identified, with a corresponding incidence rate of 14.77 cases per 1000 person-years (95%CI 9.43 to 20.11), and a case fatality ratio (CFR) of 7.28% (95%CI 4.94 to 10.60). Attack rates were higher in adults (8.49%, 95%CI 5.16 to 13.67) than in children (4.79%, 95%CI 3.05 to 7.45), with similar CFR (5.99%, 95%CI 2.31 to 14.63 vs. 5.85%, 95%CI 3.35 to 10.02). By assuming RSV attack rates as a reference group, influenza (RR 0.518; 95%CI 0.446 to 0.601), adenovirus (RR 0.679, 95%CI 0.553 to 0.830), and human metapneumovirus (RR 0.536, 95%CI 0.438 to 0.655) were associated with a substantially reduced risk for developing corresponding respiratory infection. Despite the heterogeneous settings and the uneven proportion of adult and pediatric cases, our study has identified high attack rates and a substantial CFR of RSV in recipients of BMT, stressing the importance of specifically tailored preventive strategies and the need for effective treatment options.

Ribavirin treatment for respiratory syncytial virus infection in patients with haematologic malignancy and haematopoietic stem cell transplant recipients: a systematic review and meta-analysis

BACKGROUND

Ribavirin use for respiratory syncytial virus (RSV) infection in patients with haematologic malignancies (HM) and haematopoietic stem cell transplant (HSCT) recipients remains controversial.

OBJECTIVES

To summarize the current evidence of ribavirin treatment in association with mortality and progression to lower respiratory tract infection (LRTI) among patients with HM/HSCT with RSV infection.

DATA SOURCES

MEDLINE, Embase, and the Institute for Scientific Information Web of Science.

STUDY ELIGIBILITY CRITERIA

Randomized controlled trials and observational studies investigating the effects of ribavirin, compared with treatment without ribavirin, for RSV infection.

PARTICIPANTS

Patients with HM/HSCT.

INTERVENTIONS

Ribavirin versus no ribavirin.

ASSESSMENT OF RISK OF BIAS

The risk of bias in non-randomized studies of exposure (ROBIN-E).

METHODS OF DATA SYNTHESIS

The random-effects model was used to calculate the pooled OR (pOR) with 95% CI for the pooled effect estimates of ribavirin benefits. Grading of recommendation assessment, development, and evaluation was used to evaluate the certainty of evidence.

RESULTS

One randomized controlled trial and 14 observational studies were included, representing 1125 patients with HM/HSCT. Ribavirin use was not associated with lower all-cause or RSV-associated mortality with pORs [95% CI] of 0.81 [0.40, 1.66], I2 = 55% (low certainty of evidence) and 0.48 [0.11, 2.15], I2 = 64% (very low certainty of evidence), respectively. In subgroup analyses, ribavirin use was associated with lower mortality in patients with HM/HSCT with LRTI with pOR [95% CI] of 0.19 [0.07, 0.51], I2 = 0% (moderate certainty of evidence). In subgroup analyses among studies providing adjusted OR, ribavirin use was associated with lower all-cause mortality with pOR of 0.41 [0.23, 0.74], I2 = 0% (moderate certainty of evidence). In addition, aerosolized ribavirin was associated with lower progression to LRTI with pOR [95% CI] of 0.27 [0.09, 0.80], I2 = 71% (low certainty of evidence).

CONCLUSIONS

Ribavirin may be a reasonable option to treat RSV in patients with HM/HSCT in the absence of other effective antiviral agents.

Characteristics, Management, and Outcomes of Community-Acquired Pneumonia due to Respiratory Syncytial Virus: A Retrospective Study

Background

Respiratory syncytial virus (RSV), a well-known cause of bronchiolitis in children, can cause community-acquired pneumonia (CAP) in adults, but this condition is not well studied. Hence, we described the characteristics and outcomes of patients hospitalized for CAP due to RSV.

Methods

This was a retrospective study of patients admitted to a tertiary-care hospital between 2016 and 2019 with CAP due to RSV diagnosed by a respiratory multiplex PCR within 48 hours of admission. We compared patients who required ICU admission to those who did not.

Results

Eighty adult patients were hospitalized with CAP due to RSV (median age 69.0 years, hypertension 65.0%, diabetes 58.8%, chronic respiratory disease 52.5%, and immunosuppression 17.5%); 19 (23.8%) patients required ICU admission. The median pneumonia severity index score was 120.5 (140.0 for ICU and 102.0 for non-ICU patients; p = 0.09). Bacterial coinfection was rare (10.0%). Patients who required ICU admission had more hypotension (systolic blood pressure < 90 mmHg) and a higher prevalence of bilateral infiltrates on chest X-ray (CXR) (89.5% versus 32.7%; p < 0.001). Systemic corticosteroids were used in 57.3% of patients (median initial dose was 40 mg of prednisone equivalent) with ICU patients receiving a higher dose compared to non-ICU patients (p = 0.02). Most (68.4%) ICU patients received mechanical ventilation (median duration of 4 days). The overall hospital mortality was 8.8% (higher for ICU patients: 31.6% versus 1.6%, p < 0.001).

Conclusions

Most patients with CAP due to RSV were elderly and had significant comorbidities. ICU admission was required in almost one in four patients and was associated with higher mortality.

Identification of potential immune/diagnosis related gene-immunocyte subtype networks in extracellular immune response to respiratory syncytial virus infection

INTRODUCTION

Respiratory syncytial virus (RSV) is one of the important pathogenic agents of pediatric respiratory tract infection. Weighted gene co-expression network analysis (WGCNA) is used to study autoimmune diseases, which can find potential hub genes. The diagnostic model based on hub genes and machine learning makes it possible to diagnose the extracellular immune response to RSV infection early.

OBJECTIVE

The aim of the present study was to identify potential immune, diagnose and treatment related genes expressed in RSV-infected cells.

METHODS

Firstly, gene expression data were downloaded from the Gene Expression Omnibus (GEO) to identify differentially expressed genes (DEGs). Secondly, WGCNA was performed based on DEGs to obtain hub genes related to immunity score. Thirdly, protein-protein interaction (PPI) and the immune infiltration analysis of hub immune related genes were performed. Finally, diagnostic and immune related genes were identified by machine learning, followed by functional analysis.

RESULTS

Totally, 2063 DEGs were identified in the extracellular immune response to RSV infection. Among which, 10 key immune and diagnosis related genes were identified, including ITGA2B, GP9, ITGB3, SELP, PPBP, MPL, CXCL8, NFE2, PTGS1 and LY6G6F. Several immune/diagnosis related gene-immunocyte subtype networks were identified, such as CXCL8-Type 17 T helper cell, LY6G6F-CD56 bright natural killer cell, PPBP-activated CD4 T cell/T follicular helper cell, NFE2/PTGS1/SELP-activated dendritic cell, GP9/ITGA2B/MPL-activated CD8 T cell. ITGB3, MPL and PTGS1 could be considered as therapeutic targets. Some significantly enriched signaling pathways were identified, including hematopoietic cell lineage (involving GP9 and ITGA2B), cytokine-cytokine receptor interaction (involving MPL), chemokine signaling pathway (involving PPBP) and arachidonic acid metabolism (involving PTGS1).

CONCLUSIONS

The 10-immune related gene signature may be used as potential diagnostic markers for the extracellular immune response to RSV infection, which may provide a new field in searching for diagnostic and therapeutic molecules in the extracellular immune response to RSV infection.

Review of respiratory syncytial virus infection among older adults and transplant recipients

Respiratory syncytial virus (RSV) is a common cause of pulmonary infection among children and has been increasingly recognized as an important respiratory pathogen in older adults and immunocompromised hosts. Among older adults, RSV can lead to exacerbations of underlying lung and cardiac disease. It is also associated with significant morbidity and mortality in hematopoietic stem cell transplant (HSCT) and solid organ transplant (SOT) recipients and may be associated with acute rejection and chronic lung allograft dysfunction among lung transplant recipients (LTRs). Current treatment options for severe RSV disease are limited, and there is a paucity of guidance on RSV treatment among older adults. This narrative review provides a comprehensive overview of RSV disease in older adults, HSCT recipients, and SOT recipients. Nosocomial spread has been reported, thus highlighting the importance of infection prevention and control measures to prevent outbreaks. Antivirals, monoclonal antibodies for immunoprophylaxis, and vaccine development are underway; however, future research is still needed in these critical areas.

Phenotypes, Lung Microbiota and Cytokine Responses in Pneumonia After Hematopoietic Stem Cell Transplantation

Objective

We aim to identify phenotypes of hematopoietic stem cell transplantation (HSCT) patients with pneumonia, discover relations of microbiota composition, cytokine profile, and outcomes between phenotypes. Specific cytokines will be evaluated for their role in lung injury in a murine model.

Methods

HSCT patients with pneumonia were included, and clustering of variables including cytokine levels provided the phenotypes. Outcomes were compared between phenotypes. Analysis of lung microbiota identified marker species of phenotypes. In the murine model, marker species-related cytokine regulations and the role of cytokines in lung injury were evaluated.

Results

Seventy-two patients were included, and two phenotypes were identified, namely "reactive" (N=21) and "nonreactive" (N=51) phenotype. Compared to their counterparts, patients with nonreactive phenotype had lower serum IL-6, IL-8, less severe inflammation, worse outcomes and more viruses as marker species in lung microbiota. The animal study validated the pathogens specific cytokine responses that presented in the human study and the potential protective role of IL-6 in these patients.

Conclusion

HSCT patients with pneumonia can be clustered into two phenotypes with different marker species and outcomes: the "nonreactive" phenotype and the "reactive" phenotype. Serum cytokine levels were different between the two phenotypes, which indicate the existence of the pathogen-related cytokine responses. For patients with the "nonreactive" phenotype, IL-6 therapy may improve their prognosis, which should be further tested in clinical studies.

Evaluation of prognostic scores for respiratory syncytial virus infection in a French multicentre cohort of allogeneic haematopoietic stem cell transplantation recipients

Haematopoietic stem cell transplantation (HSCT) recipients are at risk for severe respiratory syncytial virus (RSV) infection. Two prognostic scores have been proposed to predict the risk of progression from upper respiratory tract infection (URTI) to lower respiratory tract infection (LRTI) and death. This was a multicentre study of allogeneic HSCT recipients diagnosed with an RSV infection between 2010 and 2019 who were retrospectively stratified by the immunodeficiency scoring index (ISI) and the severe immunodeficiency (SID) score. Endpoints were overall survival, RSV-attributable mortality and progression to LRTI after URTI. Prognostic analyses were performed using Cox regression models. We included 147 consecutive patients, including 94 (63.9%) initially diagnosed with URTI and 53 (36.1%) with LRTI. At 90 days, 14 patients had died (survival rate, 90.5%; 95% CI: 85.9-95.3), and nine deaths were attributable to RSV (attributable mortality rate, 5.4%; 95% CI: 2.5-10.0). The cumulative 90-day incidence of LRTI after URTI was 13.8% (95% CI: 7.8-21.6). Neither score showed prognostic value for mortality, while the ISI allowed the prediction of progression to LRTI (p = 0.0008). Our results do not fully replicate the results previously reported in cohorts of HSCT recipients. This may reflect the recent epidemiology of RSV infections in this HSCT cohort.

A Phase 2, Randomized, Double-blind, Placebo-Controlled Trial of Presatovir for the Treatment of Respiratory Syncytial Virus Upper Respiratory Tract Infection in Hematopoietic-Cell Transplant Recipients

Background

Hematopoietic-cell transplant (HCT) recipients are at risk for severe respiratory syncytial virus (RSV) infection. We evaluated the RSV fusion inhibitor presatovir in a randomized, double-blind, Phase II trial in HCT recipients with RSV upper respiratory tract infections.

Methods

Patients were stratified by lymphopenia (<200/µL) and ribavirin use; were randomized, stratified by lymphopenia (<200/μL) and ribavirin use, to receive oral presatovir at 200 mg or a placebo on Days 1, 5, 9, 13, and 17, and were followed through Day 28. The coprimary efficacy endpoints were the time-weighted average change in the nasal RSV viral load between Days 1 and 9 and the proportion of patients developing lower respiratory tract complications (LRTCs) through Day 28.

Results

From 23 January 2015 to 16 June 2017, 189 patients were randomly assigned to treatment (96 to presatovir and 93 to the placebo). Presatovir treatment, compared with the placebo treatment, did not significantly affect (prespecified α = 0.01) a time-weighted average decline in the RSV viral load from Day 1 to 9 (treatment difference, −0.33 log₁₀ copies/mL; 95% confidence interval [CI] −.64 to −.02 log₁₀ copies/mL; P = .040) or the progression to LRTC (11.2% vs 19.5%, respectively; odds ratio, 0.50; 95% CI, .22–1.18; P = .11). In a post hoc analysis among patients with lymphopenia, presatovir decreased LRTC development by Day 28 (2/15 [13.3%] vs 9/14 [64.3%], respectively; P = .008), compared with the placebo. Adverse events were similar for patients receiving presatovir and the placebo.

Conclusions

Presatovir had a favorable safety profile in adult HCT recipients with RSV but did not achieve the coprimary endpoints. Exploratory analyses suggest an antiviral effect among patients with lymphopenia.

Clinical Trials Registration

NCT02254408; EUDRA-CT#2014-002474-36.

Clinical Pediatric Screening for COVID-19

Background: Due to the increasing prevalence of covid-19, the World Health Organization declared on 30 January 2020, the spread of the new coronavirus as a 6th public health emergency of international concern. Objectives: To assess the extent of the disease in the pediatric population in our region, we conducted a clinical pediatric screening for Covid-19 and evaluated factors that affected its manifestation in children. Methods: In this study, 474761 children under 19 years of age were screened in two phases. In the first phase, 680 cases were considered as suspect and referred to the health centers, where the second phase of screening took place. Finally, 230 probable cases were referred to specialized centers for further investigation. Results: Almost all of the cases had pneumonia and symptoms of shortness of breath, cough, and fever over 38°C (56.7%). Other clinical symptoms included hypotension (17.4%), Hemoptysis (16.1), sore throat (11.6%) and difficult breathing (6.7%). 26% of patients had a history of chronic disease (mainly pulmonary and cardiac). There was a statistically significant relationship between the probable causes and the symptoms of the disease (P < 0.05), between age and probable cases (P < 0.05), and between death and underlying disease (P < 0.05). However, of all the cases, only 15 (6.5%) had a positive PCR test, 39 patients were hospitalized (17%), 173 cases (75%) received outpatient treatment and 18 cases (7.8%) died. Conclusions: Children with shortness of breath, cough, pneumonia, fever over 38 and underlying disease are suspicious for Covid-19 and should be hospitalized to be evaluated with laboratory tests.

Are Community Acquired Respiratory Viral Infections an Underestimated Burden in Hematology Patients?

Despite a plethora of studies demonstrating significant morbidity and mortality due to community-acquired respiratory viral (CRV) infections in intensively treated hematology patients, and despite the availability of evidence-based guidelines for the diagnosis and management of respiratory viral infections in this setting, there is no uniform inclusion of respiratory viral infection management in the clinical hematology routine. Nevertheless, timely diagnosis and systematic management of CRV infections in intensively treated hematology patients has a demonstrated potential to significantly improve outcome. We have briefly summarized the recently published data on CRV infection epidemiology, as well as guidelines on the diagnosis and management of CRV infections in patients intensively treated for hematological malignancies. We have also assessed available treatment options, as well as mentioned novel agents currently in development.

A clinical approach to respiratory disease in patients with hematological malignancy, with a focus on respiratory infection

Respiratory complications, in particular infections, are common in the setting of hematological malignancy and after hematopoetic stem cell transplant. The symptoms can be nonspecific; therefore, it can be difficult to identify and treat the cause. However, an understanding of the specific immune defect, clinical parameters such as speed of onset, and radiological findings, allows the logical diagnostic and treatment plan to be made. Radiological findings can include consolidation, nodules, and diffuse changes such as ground glass and tree-in-bud changes. Common infections that induce these symptoms include bacterial pneumonia, invasive fungal disease, Pneumocystis jirovecii and respiratory viruses. These infections must be differentiated from inflammatory complications that often require immune suppressive treatment. The diagnosis can be refined with the aid of investigations such as bronchoscopy, computed tomography (CT) guided lung biopsy, culture, and serological tests. This article gives a schema to approach patients with respiratory symptoms in this patient group; however, in the common scenario of a rapidly deteriorating patient, treatment often has to begin empirically, with the aim to de-escalate treatment subsequently after targeted investigations.

Community-Acquired Respiratory Viruses in Transplant Patients: Diversity, Impact, Unmet Clinical Needs

Patients undergoing solid-organ transplantation (SOT) or allogeneic hematopoietic cell transplantation (HCT) are at increased risk for infectious complications. Community-acquired respiratory viruses (CARVs) pose a particular challenge due to the frequent exposure pre-, peri-, and posttransplantation. Although influenza A and B viruses have a top priority regarding prevention and treatment, recent molecular diagnostic tests detecting an array of other CARVs in real time have dramatically expanded our knowledge about the epidemiology, diversity, and impact of CARV infections in the general population and in allogeneic HCT and SOT patients. These data have demonstrated that non-influenza CARVs independently contribute to morbidity and mortality of transplant patients. However, effective vaccination and antiviral treatment is only emerging for non-influenza CARVs, placing emphasis on infection control and supportive measures. Here, we review the current knowledge about CARVs in SOT and allogeneic HCT patients to better define the magnitude of this unmet clinical need and to discuss some of the lessons learned from human influenza virus, respiratory syncytial virus, parainfluenzavirus, rhinovirus, coronavirus, adenovirus, and bocavirus regarding diagnosis, prevention, and treatment.

Treatment stratification of respiratory syncytial virus infection in allogeneic stem cell transplantation

BACKGROUND

Due to paucity of evidence to guide management of allogeneic haematopoietic stem cell transplantation (allo-HSCT) patients with respiratory syncytial virus (RSV) infections national and international guidelines make disparate recommendations.

METHODS

The outcomes of allo-HSCT recipients with RSV infection between 2015 and 2017 were assessed using the following treatment stratification; upper respiratory tract infections (URTI) being actively monitored and lower respiratory tract infections (LRTI) treated with short courses of oral ribavirin combined with intravenous immunoglobulin (IVIG, 2 g/kg).

RESULTS

During the study period 49 RSV episodes were diagnosed (47% URTI and 53% LRTI). All patients with URTI recovered without pharmacological intervention. Progression from URTI to LRTI occurred in 15%. Treatment with oral ribavirin given until significant symptomatic improvement (median 7 days [3-12]) and IVIG for LRTI was generally well tolerated. RSV-attributable mortality was low (2%).

CONCLUSIONS

In this cohort study, we demonstrate that active monitoring of allo-HSCT patients with RSV in the absence of LRTI was only associated with progression to LRTI in 15% of our patients and therefore appears to be a safe approach. Short course oral ribavirin in combination with IVIG was effective and well-tolerated for LRTI making it a practical alternative to aerosolised ribavirin. This approach was beneficial in reducing hospitalisation, saving nursing times and by using oral as opposed to nebulised ribavirin.

Antibody and B cell responses to an investigational adjuvanted RSV vaccine for older adults

Background: Infections with respiratory syncytial virus (RSV) cause significant morbidity and hospitalization in older adults. We studied the humoral, mucosal and B cell responses of an investigational adjuvanted RSV sF vaccine, MEDI7510, in older adults. Methods: In a substudy of a randomized (1:1), double-blind, placebo-controlled study of MEDI7510 in adults ≥60 years of age, we collected blood and nasal secretions at days 0, 8, 29, 91 and 180 post-vaccination to measure F-specific IgG and IgA antibodies by ELISA, and plasmablasts and memory B cells by IgA/IgG dual-color fluorospot. Results: The 27 vaccine- and 18 placebo-recipients had a mean age of 73 years and included 24 women. Among vaccinees, 93% had significant increases in F-specific plasma IgG 85% had increased plasma IgA; 74% had increased nasal IgG and 26% nasal IgA; 93% had IgG and 89% IgA plasmablasts on Day 8 post-immunization; and 82% had IgG and 7.4% IgA memory B cell responses to the vaccine. Vaccinees <70 years of age and women had the highest responses to the vaccine. Conclusions: This adjuvanted vaccine generated robust humoral immune responses in older adults, including RSV F-specific systemic and mucosal antibodies and memory B cells. Nevertheless, age ≥70 years was associated with decreased immunogenicity of the adjuvanted vaccine.

Clinical Features, Severity, and Incidence of RSV Illness During 12 Consecutive Seasons in a Community Cohort of Adults ≥60 Years Old

Background

The epidemiology and burden of respiratory syncytial virus (RSV) illness are not well defined in older adults.

Methods

Adults ≥60 years old seeking outpatient care for acute respiratory illness were recruited from 2004–2005 through 2015–2016 during the winter seasons. RSV was identified from respiratory swabs by multiplex polymerase chain reaction. Clinical characteristics and outcomes were ascertained by interview and medical record abstraction. The incidence of medically attended RSV was estimated for each seasonal cohort.

Results

RSV was identified in 243 (11%) of 2257 enrollments (241 of 1832 individuals), including 121 RSV type A and 122 RSV type B. The RSV clinical outcome was serious in 47 (19%), moderate in 155 (64%), and mild in 41 (17%). Serious outcomes included hospital admission (n = 29), emergency department visit (n = 13), and pneumonia (n = 23) and were associated with lower respiratory tract symptoms during the enrollment visit. Moderate outcomes included receipt of a new antibiotic prescription (n = 144; 59%), bronchodilator/nebulizer (n = 45; 19%), or systemic corticosteroids (n = 28; 12%). The relative risk of a serious outcome was significantly increased in persons aged ≥75 years (vs 60–64 years) and in those with chronic obstructive pulmonary disease or congestive heart failure. The average seasonal incidence was 139 cases/10 000, and it was significantly higher in persons with cardiopulmonary disease compared with others (rate ratio, 1.89; 95% confidence interval, 1.44–2.48).

Conclusions

RSV causes substantial outpatient illness with lower respiratory tract involvement. Serious outcomes are common in older patients and those with cardiopulmonary disease.

A multifaceted approach to RSV vaccination

Respiratory Syncytial Virus (RSV) is the leading cause of pneumonia and bronchiolitis in infants, resulting in significant morbidity and mortality worldwide. In addition, RSV infections occur throughout different ages, thus, maintaining the virus in circulation, and increasing health risk to more susceptible populations such as infants, the elderly, and the immunocompromised. To date, there is no vaccine approved to prevent RSV infection or minimize symptoms of infection. Current clinical trials for vaccines against RSV are being carried out in four very different populations. There are vaccines that target two different pediatric populations, infants 2 to 6 month of age and seropositive children over 6 months of age, as well as women (non-pregnant or pregnant in their third trimester). There are vaccines that target adult and elderly populations. In this review, we will present and discuss RSV vaccine candidates currently in clinical trials. We will describe the preclinical studies instrumental for their advancement, with the goal of introducing new preclinical models that may more accurately predict the outcome of clinical vaccine studies.

Transmission and Control of Respiratory Viral Infections in the Healthcare Setting

Purpose of the review

Viral respiratory infections have been recognized as a cause of severe illness in immunocompromised and non-immunocompromised hosts. This acknowledgement is a consequence of improvement in diagnosis and better understanding of transmission. Available vaccines and antiviral drugs for prophylaxis and treatment have been developed accordingly. Viral respiratory pathogens are increasingly recognized as nosocomial pathogens as well. The purpose of this review is to describe the most frequent and relevant nosocomial viral respiratory infections, their mechanisms of transmission and the infection control measures to prevent their spread in the healthcare setting.

Recent findings

Although most mechanisms of transmission and control measures of nosocomial viral infections are already known, improved diagnostic tools allow better characterization of these infections and also lead to the discovery of new viruses such as the coronavirus, which is the cause of the Middle East Respiratory Syndrome, or the human bocavirus. Also, the ability to understand better the impact, dissemination and prevention of these viruses, allows us to improve the measures to prevent these infections.

Summary

Healthcare viral respiratory infections increase patient morbidity. Each virus has a different mechanism of transmission; therefore, early detection and prompt implementation of infection control measures are very important in order to avoid their transmission in the hospital setting.

Comparative effectiveness of aerosolized versus oral ribavirin for the treatment of respiratory syncytial virus infections: A single-center retrospective cohort study and review of the literature

BACKGROUND

Respiratory syncytial virus (RSV) is a leading cause of viral infections in immunocompromised hosts and is associated with significant morbidity and mortality. In January 2015, our institution switched from aerosolized to oral ribavirin (RBV) for primary treatment of RSV infection among high-risk immunocompromised adult patients. The objective of the study was to evaluate the clinical and economic outcomes associated with this switch.

METHODS

Retrospective cohort analysis of adult patients diagnosed with RSV infection and treated with RBV between January 1, 2013, and May 31, 2016.

RESULTS

Of 46 patients, 20 (43%) patients received oral RBV and 26 (57%) received aerosolized RBV. Underlying conditions included lung transplant (n = 22), hematopoietic cell transplant (n = 16), hematological malignancy (n = 5), and structural lung diseases (n = 4). At the time of RSV diagnosis, 42 (91%) were hospitalized, 36 (78%) had clinical and radiographic evidence of lower respiratory tract infection (RTI), 9 (20%) were admitted to the ICU, and 4 (9%) required intubation. There were no differences in clinical outcomes between the 2 groups with regard to adverse events, progression from upper to lower RTI, escalation of care, or 30-day mortality. Three (15%) in the oral group and 1 (4%) in the aerosolized group died within 30 days (P = .33). The cost avoidance attributable to the switch in therapy over 1 year is $1.2 million.

CONCLUSION

Oral RBV appears to be a safe and cost-effective alternative to aerosolized RBV for the management of RSV infection in immunocompromised patients. Larger studies are needed to validate the safety and efficacy of this approach.

Post-transplant Viral Respiratory Infections in the Older Patient: Epidemiology, Diagnosis, and Management

Organ and stem cell transplantation has been one of the greatest advances in modern medicine, and is the primary treatment modality for many end-stage diseases. As our population ages, so do the transplant recipients, and with that comes many new challenges. Respiratory viruses have been a large contributor to the mortality and morbidity of solid organ transplant (SOT) and hematopoietic stem cell transplant (HSCT) recipients. Respiratory viruses are generally a long-term complication of transplantation and primarily acquired in the community. With the emergence of molecular methods, newer respiratory viruses are being detected. Respiratory viruses appear to cause severe disease in the older transplant population. Influenza vaccine remains the mainstay of prevention in transplant recipients, although immunogenicity of current vaccines is suboptimal. Limited therapies are available for other respiratory viruses. The next decade will likely bring newer antivirals and vaccines to the forefront. Our goal is to provide the most up to date knowledge of respiratory viral infections in our aging transplant population.

Virus infection facilitates the development of severe pneumonia in transplant patients with hematologic malignancies

Allogeneic hematopoietic stem cell transplantation (HSCT) is an effective therapy for patients with hematologic malignancies. Severe pneumonia is associated with high mortality rate in HSCT recipients. Viral co-infection indicates a poor prognosis of HSCT recipients. In this study, a total of 68 allogeneic HSCT recipients were included. Cytomegalovirus (CMV) and Respiratory syncytial virus (RSV) infection was assessed by testing peripheral blood and oropharynx swabs, respectively, collected in the first 180 days after transplantation. We analysed the correlation of CMV and RSV co-infection with severe pneumonia and mortality. The incidence of CMV and RSV co-infection was 26.5% (18/68). Severe pneumonia was diagnosed in 61% (11/18) cases with co-infection compared to only 10% (5/50) cases with mono-infection or no infection. The analysis of potential risk factors for severe pneumonia showed that CMV and RSV co-infection was significantly associated with severe pneumonia (p < 0.001). The 5 patients who died of severe pneumonia were all co-infected with CMV and RSV. In conclusion, CMV and RSV co-infection appears to be an important factor and facilitates the development of severe pneumonia in allogeneic HSCT patients with hematologic malignancies.

Respiratory viruses in transplant recipients: more than just a cold. Clinical syndromes and infection prevention principles

OBJECTIVES

The aim of this review is to provide updated information on the clinical spectrum, treatment options, and infection prevention strategies for respiratory viral infections (RVIs) in both solid organ (SOT) and hematopoietic stem cell transplant (HSCT) patients.

METHODS

The MEDLINE and PubMed databases were searched for literature regarding the aforementioned aspects of RVIs, with focus on respiratory syncytial virus, adenovirus, influenza virus, parainfluenza virus, human metapneumovirus, and rhinovirus.

RESULTS

Compared to immunocompetent hosts, SOT and HSCT patients are much more likely to experience a prolonged duration of illness, prolonged shedding, and progression of upper respiratory tract disease to pneumonia when infected with respiratory viruses. Adenovirus and respiratory syncytial virus tend to have the highest mortality and risk for disseminated disease, but all the RVIs are associated with higher morbidity and mortality in these patients than in the general population. These viruses are spread via direct contact and aerosolized droplets, and nosocomial spread has been reported.

CONCLUSIONS

RVIs are associated with high morbidity and mortality among SOT and HSCT recipients. Management options are currently limited or lack strong clinical evidence. As community and nosocomial spread has been reported for all reviewed RVIs, strict adherence to infection control measures is key to preventing outbreaks.

Human rhinovirus detection in the lower respiratory tract of hematopoietic cell transplant recipients: association with mortality

Human rhinoviruses are the most common respiratory viruses detected in patients after hematopoietic cell transplantation. Although rhinovirus appears to occasionally cause severe lower respiratory tract infection in immunocompromised patients, the clinical significance of rhinovirus detection in the lower respiratory tract remains unknown. We evaluated 697 recipients transplanted between 1993 and 2015 with rhinovirus in respiratory samples. As comparative cohorts, 273 recipients with lower respiratory tract infection caused by respiratory syncytial virus (N=117), parainfluenza virus (N=120), or influenza (N=36) were analyzed. Factors associated with mortality were analyzed using Cox proportional hazard models. Among 569 subjects with rhinovirus upper respiratory tract infection and 128 subjects with rhinovirus lower respiratory tract infection, probabilities of overall mortality at 90 days were 6% and 41%, respectively (P<0.001). The survival rate after lower respiratory tract infection was not affected by the presence of co-pathogens (55% in patients with co-pathogens, 64% in patients without, P=0.34). Low monocyte count (P=0.027), oxygen use (P=0.015), and steroid dose greater than 1 mg/kg/day (P=0.003) before diagnosis were significantly associated with mortality among patients with lower respiratory tract infection in multivariable analysis. Mortality after rhinovirus lower respiratory tract infection was similar to that after lower respiratory tract infection by respiratory syncytial virus, parainfluenza virus or influenza in an adjusted model. In summary, transplant recipients with rhinovirus detection in the lower respiratory tract had high mortality rates comparable to viral pneumonia associated with other well-established respiratory viruses. Our data suggest rhinovirus can contribute to severe pulmonary disease in immunocompromised hosts.

Viral Pneumonia in Patients with Hematologic Malignancy or Hematopoietic Stem Cell Transplantation

Viral pneumonias in patients with hematologic malignancies and recipients of hematopoietic stem cell transplantation cause significant morbidity and mortality. Advances in diagnostic techniques have enabled rapid identification of respiratory viral pathogens from upper and lower respiratory tract samples. Lymphopenia, myeloablative and T-cell depleting chemotherapy, graft-versus-host disease, and other factors increase the risk of developing life-threatening viral pneumonia. Chest imaging is often nonspecific but may aid in diagnoses. Bronchoscopy with bronchoalveolar lavage is recommended in those at high risk for viral pneumonia who have new infiltrates on chest imaging.

Respiratory syncytial virus outbreak on an adult stem cell transplant unit

BACKGROUND

An increase in respiratory syncytial virus type B (RSV-B) infections was detected on an adult hematology/oncology and stem cell transplant unit during March 2015. This prompted an outbreak investigation.

METHODS

Nosocomial cases were defined as RSV-B-positive patients who developed respiratory virus symptoms ≥ 7 days after admission to the unit or were readmitted with symptoms ≤ 7 days since last discharge from the unit. Strict outbreak control measures were implemented to stop the outbreak.

RESULTS

During the outbreak, 19 cases of RSV-B were detected, 14 among patients and 5 among health care workers (HCWs). Additionally, 2 HCWs tested positive for respiratory syncytial virus type A and 1 tested positive for influenza B among the 27 symptomatic HCWs evaluated. No specific antiviral therapy was given and all cases recovered without progression to lower respiratory tract infection. After no new cases were identified for 2 weeks, the outbreak was declared over.

CONCLUSIONS

High vigilance for respiratory viruses on high-risk inpatient units is required for detection and prevention of potential outbreaks. Multiple respiratory viruses with outbreak potential were identified among HCWs. HCWs with respiratory virus symptoms should not provide direct patient care. Absence of lower respiratory tract infection suggests lower virulence of RSV-B, compared with respiratory syncytial virus type A, among immunocompromised adults.

Infectious diseases in allogeneic haematopoietic stem cell transplantation: prevention and prophylaxis strategy guidelines 2016

Infectious complications after allogeneic haematopoietic stem cell transplantation (allo-HCT) remain a clinical challenge. This is a guideline provided by the AGIHO (Infectious Diseases Working Group) of the DGHO (German Society for Hematology and Medical Oncology). A core group of experts prepared a preliminary guideline, which was discussed, reviewed, and approved by the entire working group. The guideline provides clinical recommendations for the preventive management including prophylactic treatment of viral, bacterial, parasitic, and fungal diseases. The guideline focuses on antimicrobial agents but includes recommendations on the use of vaccinations. This is the updated version of the AGHIO guideline in the field of allogeneic haematopoietic stem cell transplantation utilizing methods according to evidence-based medicine criteria.

Critical Care Aspects of Lung Transplant Patients

Major strides have been made in lung transplantation during the 1990s and it has become an established treatment option for patients with advanced lung disease. Due to improvements in organ preservation, surgical techniques, postoperative intensive care, and immunosuppression, the risk of perioperative and early mortality (less than 3 months after transplantation) has declined [1]. The transplant recipient now has a greater chance of realizing the benefits of the long and arduous waiting period.

Despite these improvements, suboptimal long-term outcomes continue to be shaped by issues such as opportunistic infections and chronic rejection. Because of the wider use of lung transplantation and the longer life span of recipients, intensivists and ancillary intensive care unit (ICU) staff should be well versed with the care of lung transplant recipients.

In this clinical review, issues related to organ donation will be briefly mentioned. The remaining focus will be on the critical care aspects of lung transplant recipients in the posttransplant period, particularly ICU management of frequently encountered conditions. First, the groups of patients undergoing transplantation and the types of procedures performed will be outlined. Specific issues directly related to the allograft, including early graft dysfunction from ischemia-reperfusion injury, airway anastomotic complications, and infections in the setting of immunosuppression will be emphasized. Finally nonpulmonary aspects of posttransplant care and key pharmacologic points in the ICU will be covered.

Corticosteroid use as adjunct therapy for respiratory syncytial virus infection in adult allogeneic stem cell transplant recipients

BACKGROUND

Respiratory syncytial virus (RSV) infection causes significant morbidity and mortality in allogeneic stem cell transplant (allo-SCT) recipients. Although ribavirin and immunoglobulins are common components of therapy, the role of adjunct corticosteroids is not established.

OBJECTIVES

We sought to evaluate corticosteroid utilization in the setting of post-allo-SCT RSV infection in our center and assess post-transplant outcomes including pulmonary function decline.

METHODS

Patients with a history of RSV infection from 2008 to 2014 seen at our institution were identified. Treatment and outcome data were retrospectively collected. Forced expiratory volume at 1 s (FEV1) and carbon monoxide diffusion capacity (DLCO) were collected pre- and post-RSV infection.

RESULTS

During the observation period, RSV was isolated in 53 of 552 patients undergoing allo-SCT (10%) and 45 had evaluable therapy data. RSV-related mortality in this cohort was 4/45 (9%). Twenty-one (47%) were on corticosteroids prior to RSV diagnosis, of whom 11 (24%) had a dose increase post symptom onset. Eight (18%) patients were started on corticosteroids at the time of RSV infection. Corticosteroid therapy at symptom onset was associated with a higher rate of upper respiratory infection (URTI) to lower respiratory infection (LRTI) progression risk ratio (RR) 2.49 (1.21-5.13; P = 0.016), hospital admission RR 2.05 (1.24-3.37; P = 0.005), or intensive care unit admission RR 2.91 (1.89-5.01; P = 0.002). No significant difference was seen with FEV1 and DLCO decline (P = 0.3 and 0.24, respectively) or mortality (P = 0.26).

CONCLUSION

Adjunct corticosteroid use in the setting of RSV infection did not improve RSV-related outcomes including long-term pulmonary function. Our results do not support the routine use of corticosteroids; however, this finding does need to be verified in a larger cohort of patients.

Risk of nosocomial respiratory syncytial virus infection and effectiveness of control measures to prevent transmission events: a systematic review

Respiratory syncytial virus (RSV) causes a significant public health burden, and outbreaks among vulnerable patients in hospital settings are of particular concern. We reviewed published and unpublished literature from hospital settings to assess: (i) nosocomial RSV transmission risk (attack rate) during outbreaks, (ii) effectiveness of infection control measures. We searched the following databases: MEDLINE, EMBASE, CINAHL, Cochrane Library, together with key websites, journals and grey literature, to end of 2012. Risk of bias was assessed using the Cochrane risk of bias tool or Newcastle–Ottawa scale. A narrative synthesis was conducted. Forty studies were included (19 addressing research question one, 21 addressing question two). RSV transmission risk varied by hospital setting; 6–56% (median: 28·5%) in neonatal/paediatric settings (n = 14), 6–12% (median: 7%) in adult haematology and transplant units (n = 3), and 30–32% in other adult settings (n = 2). For question two, most studies (n = 13) employed multi‐component interventions (e.g. cohort nursing, personal protective equipment (PPE), isolation), and these were largely reported to be effective in reducing nosocomial transmission. Four studies examined staff PPE; eye protection appeared more effective than gowns and masks. One study reported on RSV prophylaxis for patients (RSV‐Ig/palivizumab); there was no statistical evidence of effectiveness although the sample size was small. Overall, risk of bias for included studies tended to be high. We conclude that RSV transmission risk varies widely during hospital outbreaks. Although multi‐component control strategies appear broadly successful, further research is required to disaggregate the effectiveness of individual components including the potential role of palivizumab prophylaxis.

Respiratory Syncytial Virus and Human Metapneumovirus Infection in Transplant Recipients

Respiratory viral infections due to respiratory syncytial virus (RSV) and human metapneumovirus (hMPV) cause infections in immunocompromised transplant patients ranging from mild upper respiratory infections to severe lower respiratory tract disease with respiratory failure. These viruses are more readily diagnosed due to improvements in sensitive molecular diagnostic methods. The epidemiology of RSV and hMPV is similarly becoming more readily appreciated in hematopoietic stem cell transplant (HSCT) patients of all ages as well as solid organ transplant (SOT) patients, with lung transplant recipients having evidence of more frequent and severe complications related to these viruses. RSV and hMPV infection typically but not always present with upper respiratory signs and symptoms that progress to lower respiratory tract disease. Treatment options for RSV are limited, with aerosolized, intravenous, and oral ribavirin all studied in HSCT and lung transplant patients. No antiviral therapy for the treatment of hMPV is available, although ribavirin has shown some effectiveness in vitro. New antiviral agents including RSV fusion inhibitors and nucleoside analogs are being developed, with some under clinical evaluation.

Detection of influenza vaccine effectiveness among nursery school children: Lesson from a season with cocirculating respiratory syncytial virus

In the winter influenza epidemic season, patients with respiratory illnesses including respiratory syncytial virus (RSV) infections increase among young children. Therefore, we evaluated the effectiveness of influenza vaccine against influenza-like illness (ILI) using a technique to identify outbreaks of RSV infection and to distinguish those patients from ILI patients. The study subjects were 101 children aged 12 to 84 months attending nursery school. We classified the cases into 6 levels based on the definitions of ILI for outcomes. We established observation periods according to information obtained from regional surveillance and rapid diagnostic tests among children. Multivariate odds ratios (ORs) for each case classification were obtained using a logistic regression model for each observation period. For the entire observation period, ORs for cases with fever plus respiratory symptoms were reduced marginally significantly. For the local influenza epidemic period, only the OR for the most serious cases was significantly decreased (0.20 [95%CI: 0.04-0.94]). During the influenza outbreak among the nursery school children, multivariate ORs for fever plus respiratory symptoms decreased significantly (≥ 38.0°C plus ≥ one symptoms: 0.23 [0.06-0.91), ≥ 38.0°C plus ≥ 2 symptoms: 0.21 [0.05-0.85], ≥ 39.0°C plus ≥ one symptoms: 0.18 [0.04-0.93] and ≥ 39.0°C plus ≥ 2 symptoms: 0.16 [0.03-0.87]). These results suggest that confining observation to the peak influenza epidemic period and adoption of a strict case classification system can minimize outcome misclassification when evaluating the effectiveness of influenza vaccine against ILI, even if influenza and RSV cocirculate in the same season.

Infection Prevention and Control in Residential Facilities for Pediatric Patients and Their Families

The Society for Healthcare Epidemiology of America (SHEA) guideline “Infection Prevention and Control in Residential Facilities for Pediatric Patients and Their Families” is the first infection prevention and control (IPC) guideline to address preventing transmission of infectious agents in “home away from home” residential settings, of which the Ronald McDonald Houses (RMHs) serve as a prototype. These types of facilities provide support services, including overnight lodging, for ill and injured children and their families. Food preparation occurs in common areas, and cleaning of rooms or apartments is performed by the occupants during their stay and before departure. Pediatric patients are frequent guests of the family-centered facilities while receiving or recovering from specialized medical therapy. Examples of high-risk populations served in these facilities include families of patients with cancer, recipients of stem cell or solid organ transplants, surgical and/or very-low-birthweight infants who receive care in neonatal intensive care units (NICUs), those with cystic fibrosis, and women with high-risk pregnancies awaiting delivery in a nearby medical center. Such facilities are located worldwide and vary in their physical structure and the predominant population served.

Agents that increase AAM differentiation blunt RSV-mediated lung pathology

RSV is the most significant cause of serious lower respiratory tract infection in infants and young children worldwide. There is currently no vaccine for the virus, and antiviral therapy (e.g., ribavirin) has shown no efficacy against the disease. We reported that alternatively activated macrophages (AAMs) mediate resolution of RSV-induced pathology. AAM differentiation requires macrophage-derived IL-4 and -13, autocrine/paracrine signaling through the type I IL-4 receptor, and STAT6 activation. Based on these findings, we reasoned that it would be possible to intervene therapeutically in RSV disease by increasing AAM differentiation, thereby decreasing lung pathology. Mice treated with the IL-4/anti-IL-4 immune complexes, shown previously to sustain levels of circulating IL-4, increased the RSV-induced AAM markers arginase-1 and mannose receptor and decreased the lung pathology. Induction of PPARγ, shown to play a role in AAM development, by the PPARγ agonist rosiglitazone or treatment of mice with the macrolide antibiotic AZM, also reported to skew macrophage differentiation to an AAM phenotype, increased the AAM markers and mitigated RSV-induced lung pathology. Collectively, our data suggest that therapeutic manipulation of macrophage differentiation to enhance the AAM phenotype is a viable approach for ameliorating RSV-induced disease.

A recombinant anchorless respiratory syncytial virus (RSV) fusion (F) protein/monophosphoryl lipid A (MPL) vaccine protects against RSV-induced replication and lung pathology

We previously demonstrated that the severe cytokine storm and pathology associated with RSV infection following intramuscular vaccination of cotton rats with FI-RSV Lot 100 could be completely abolished by formulating the vaccine with the mild TLR4 agonist and adjuvant, monophosphoryl lipid A (MPL). Despite this significant improvement, the vaccine failed to blunt viral replication in the lungs. Since MPL is a weak TLR4 agonist, we hypothesized that its adjuvant activity was mediated by modulating the innate immune response of respiratory tract resident macrophages. Therefore, we developed a new vaccine preparation with purified, baculovirus expressed, partially purified, anchorless RSV F protein formulated with synthetic MPL that was administered to cotton rats intranasally, followed by an intradermal boost. This novel formulation and heterologous "prime/boost" route of administration resulted in decreased viral titers compared to that seen in animals vaccinated with F protein alone. Furthermore, animals vaccinated by this route showed no evidence of enhanced lung pathology upon RSV infection. This indicates that MPL acts as an immune modulator that protects the host from vaccine-enhanced pathology, and reduces RSV replication in the lower respiratory tract when administered by a heterologous prime/boost immunization regimen.

Respiratory infections

The respiratory tract is a common site of infection in cancer patients and is associated with substantial moribidity and mortality in this population. Cancer, chemotherapy, and radiation can all cause noninfectious pulmonary infiltrates and respiratory symptoms that can masquerade as a respiratory tract infection. Cancer patients are at a particular risk for infection by a wide variety of different viruses, fungi, and bacteria that can be difficult to treat. Although noninvasive diagnostics have significantly improved recently, patients with severe pneumonia and those not responding to usual therapy should be candidates for aggressive diagnostic testing and tissue sampling. Initial therapy should be carefully chosen and individually tailored to account for the individual patient's underlying risk factors for multi-drug-resistant pathogens, viral pathogens, or fungi. Once diagnostic testing returns, therapy should be altered to appropriately narrow the spectrum of coverage.

Risk factors and outcomes for respiratory syncytial virus-related infections in immunocompromised children

BACKGROUND

Respiratory syncytial virus (RSV) is associated with significant morbidity and mortality in immunocompromised children. Data on the risk factors for acquisition and outcomes from RSV infections in this population are limited.

METHODS

This cohort study (2006 to 2011) included RSV-positive immunocompromised pediatric inpatients. Nasopharyngeal swabs were tested for RSV by direct immunofluorescence. Purposeful multiple regression was used to assess risk factors associated with community-acquired RSV (CA-RSV) infections and their outcomes compared with nosocomial (N-RSV) infections. Means and medians were compared using Student's t test and a nonparametric test, respectively. Proportions were compared using χ(2) or Fisher's exact test, as appropriate.

RESULTS

There were 117 RSV-positive patients of whom 42 (35.9%) presented with (N-RSV) infection. Overall, more than a third presented with lower respiratory tract infections, which resulted in a 28% admission rate to the intensive care unit and a mortality rate of 5%; the latter solely among patients with community-acquired infection. Subjects with CA-RSV presented with more advanced clinical evidence of lower tract disease with respiratory distress (eg, intercostal recession; odds ratio 2.5; 95% confidence interval: 1.1-5.6; P = 0.03) compared with those with N-RSV. Subjects with CA-RSV infections were less likely to have a prolonged hospital admission (odds ratio 0.7; 95% confidence interval: 0.5-0.8; P < 0.0001) relative to those with N-RSV infections.

CONCLUSIONS

RSV-related infections in immunocompromised children may result in poor outcomes, including mortality. Differences in mortality rates among those with CA-RSV compared with N-RSV warrant further study, with enhanced opportunities for prevention and early detection of infection.

Respiratory syncytial virus lower respiratory disease in hematopoietic cell transplant recipients: viral RNA detection in blood, antiviral treatment, and clinical outcomes

Background. Respiratory syncytial virus (RSV) pneumonia after hematopoietic cell transplant (HCT) is associated with severe morbidity. Although RSV RNA has been detected in serum from patients with RSV lower respiratory disease (LRD) after HCT, the association with clinical outcomes has not been well established in multivariable models. Additionally, the role of antiviral treatment in HCT recipients has not been previously analyzed in multivariable models.

Methods. We retrospectively identified HCT recipients with virologically confirmed RSV LRD and tested stored plasma/serum samples by quantitative reverse transcription polymerase chain reaction for RSV RNA. Risk factors for RSV RNA detection and the impact of RSV RNA in serum and antiviral therapy on outcomes were analyzed using multivariable Cox models.

Results. RSV RNA was detected in plasma or serum from 28 of 92 (30%) patients at a median of 24.5 days following HCT and 2 days following LRD. In multivariable models, neutropenia, monocytopenia, thrombocytopenia, and mechanical ventilation increased the risk of plasma/serum RSV RNA detection; lymphopenia and steroid use did not. RSV RNA detection increased the risk of overall mortality in multivariable models (adjusted hazard ratio [aHR], 2.09 [P = .02]), whereas treatment with aerosolized ribavirin decreased the risk of overall mortality and pulmonary death (aHR, 0.33 [P = .001] and aHR 0.31 [P = .003], respectively).

Conclusions. RSV RNA detection in plasma or serum may be a marker for lung injury and poor outcomes in HCT recipients with RSV LRD. Treatment with aerosolized ribavirin appeared to be protective against overall and pulmonary mortality.

Impact of aerosolized ribavirin on mortality in 280 allogeneic haematopoietic stem cell transplant recipients with respiratory syncytial virus infections

OBJECTIVES

Respiratory syncytial virus (RSV) infections are well recognized as a significant cause of morbidity and mortality in allogeneic haematopoietic stem cell transplant (allo-HSCT) recipients. We evaluated the spectrum of clinical manifestations, management (including ribavirin-based antiviral therapy) and outcomes of RSV infections and determined the risk factors associated with RSV lower respiratory tract infection (LRTI) and all-cause mortality.

METHODS

In this retrospective study, we analysed clinical data from all laboratory-confirmed RSV infections in allo-HSCT recipients (n = 280) who presented at our institution from January 1996 to May 2009.

RESULTS

Of the 280 patients, 80 (29%) developed LRTI within 20 days (median 1 day, range 0-19 days) and 44 (16%) died within 90 days (median 26 days, range 1-82 days) from RSV diagnosis. Multivariable logistic regression analyses identified several significant risk factors associated with RSV LRTI and all-cause mortality, including age, male sex, neutropenia, lymphocytopenia and lack of ribavirin-based antiviral therapy at the upper respiratory tract infection (URTI) stage. Aerosolized ribavirin-based therapy at the URTI stage was the single most significant factor in reducing the risk of RSV LRTI (83%), all-cause mortality (57%) and RSV-associated mortality (87%) in these patients (P < 0.05), irrespective of the year of RSV diagnosis.

CONCLUSIONS

Our results demonstrate that RSV infections are a significant cause of morbidity and mortality in high-risk allo-HSCT recipients and ribavirin-based antiviral therapy at the URTI stage had a positive impact on both outcomes in this vulnerable population with multiple risk factors.