The effect of ribavirin to treat previously healthy infants admitted with acute bronchiolitis on acute and chronic respiratory morbidity

Respiratory Syncytial Virus-An Update for Prenatal and Primary Health Providers

Respiratory syncytial virus (RSV) infection is a significant cause of morbidity and mortality among infants aged younger than 1 year, adults aged 65 years or older, and immunocompromised persons. Limited data exist on RSV infection in pregnancy and further research is needed. Strides are being made to develop vaccines, including vaccines for maternal immunization, as well as monoclonal antibodies for disease prevention.

Past, Present and Future Approaches to the Prevention and Treatment of Respiratory Syncytial Virus Infection in Children

INTRODUCTION

The REGAL (RSV Evidence - A Geographical Archive of the Literature) series 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 seventh and final publication covers the past, present and future approaches to the prevention and treatment of RSV infection among infants and children.

METHODS

A systematic review was undertaken of publications between January 1, 1995 and December 31, 2017 across PubMed, Embase and The Cochrane Library. Studies reporting data on the effectiveness and tolerability of prophylactic and therapeutic agents for RSV infection were included. Study quality and strength of evidence (SOE) were graded using recognized criteria. A further nonsystematic search of the published literature and Clinicaltrials.gov on antiviral therapies and RSV vaccines currently in development was also undertaken.

RESULTS

The systematic review identified 1441 studies of which 161 were included. Management of RSV remains centered around prophylaxis with the monoclonal antibody palivizumab, which has proven effective in reducing RSV hospitalization (RSVH) in preterm infants < 36 weeks' gestational age (72% reduction), children with bronchopulmonary dysplasia (65% reduction), and infants with hemodynamically significant congenital heart disease (53% reduction) (high SOE). Palivizumab has also shown to be effective in reducing recurrent wheezing following RSVH (high SOE). Treatment of RSV with ribavirin has conflicting success (moderate SOE). Antibodies with increased potency and extended half-life are currently entering phase 3 trials. There are approximately 15 RSV vaccines in clinical development targeting the infant directly or indirectly via the mother.

CONCLUSION

Palivizumab remains the only product licensed for RSV prophylaxis, and only available for high-risk infants. For the general population, there are several promising vaccines and monoclonal antibodies in various stages of clinical development, with the aim to significantly reduce the global healthcare impact of this common viral infection.

FUNDING

AbbVie.

Saline in acute bronchiolitis RCT and economic evaluation: hypertonic saline in acute bronchiolitis - randomised controlled trial and systematic review

BACKGROUND

Acute bronchiolitis is the most common cause of hospitalisation in infancy. Supportive care and oxygen are the cornerstones of management. A Cochrane review concluded that the use of nebulised 3% hypertonic saline (HS) may significantly reduce the duration of hospitalisation.

OBJECTIVE

To test the hypothesis that HS reduces the time to when infants were assessed as being fit for discharge, defined as in air with saturations of > 92% for 6 hours, by 25%.

DESIGN

Parallel-group, pragmatic randomised controlled trial, cost-utility analysis and systematic review.

SETTING

Ten UK hospitals.

PARTICIPANTS

Infants with acute bronchiolitis requiring oxygen therapy were allocated within 4 hours of admission.

INTERVENTIONS

Supportive care with oxygen as required, minimal handling and fluid administration as appropriate to the severity of the disease, 3% nebulised HS every ± 6 hours.

MAIN OUTCOME MEASURES

The trial primary outcome was time until the infant met objective discharge criteria. Secondary end points included time to discharge and adverse events. The costs analysed related to length of stay (LoS), readmissions, nebulised saline and other NHS resource use. Quality-adjusted life-years (QALYs) were estimated using an existing utility decrement derived for hospitalisation in children, together with the time spent in hospital in the trial.

DATA SOURCES

We searched MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials and other databases from inception or from 2010 onwards, searched ClinicalTrials.gov and other registries and hand-searched Chest, Paediatrics and Journal of Paediatrics to January 2015.

REVIEW METHODS

We included randomised/quasi-randomised trials which compared HS versus saline (± adjunct treatment) or no treatment. We used a fixed-effects model to combine mean differences for LoS and assessed statistical heterogeneity using the I (2) statistic.

RESULTS

The trial randomised 158 infants to HS (n = 141 analysed) and 159 to standard care (n = 149 analysed). There was no difference between the two arms in the time to being declared fit for discharge [median 76.6 vs. 75.9 hours, hazard ratio (HR) 0.95, 95% confidence interval (CI) 0.75 to 1.20] or to actual discharge (median 88.5 vs. 88.7 hours, HR 0.97, 95% CI 0.76 to 1.23). There was no difference in adverse events. One infant developed bradycardia with desaturation associated with HS. Mean hospital costs were £2595 and £2727 for the control and intervention groups, respectively (p = 0.657). Incremental QALYs were 0.0000175 (p = 0.757). An incremental cost-effectiveness ratio of £7.6M per QALY gained was not appreciably altered by sensitivity analyses. The systematic review comprised 15 trials (n = 1922) including our own. HS reduced the mean LoS by -0.36 days (95% CI -0.50 to -0.22 days). High levels of heterogeneity (I (2) = 78%) indicate that the result should be treated cautiously.

CONCLUSIONS

In this trial, HS had no clinical benefit on LoS or readiness for discharge and was not a cost-effective treatment for acute bronchiolitis. Claims that HS achieves small reductions in LoS must be treated with scepticism.

FUTURE WORK

Well-powered randomised controlled trials of high-flow oxygen are needed.

STUDY REGISTRATION

This study is registered as NCT01469845 and CRD42014007569.

FUNDING DETAILS

This project was funded by the NIHR Health Technology Assessment (HTA) programme and will be published in full in Health Technology Assessment; Vol. 19, No. 66. See the HTA programme website for further project information.

Pharmacological management of acute bronchiolitis

This article reviews the current knowledge base related to the pharmacological treatments for acute bronchiolitis. Bronchiolitis is a common lower respiratory illness affecting infants worldwide. The mainstays of therapy include airway support, supplemental oxygen, and support of fluids and nutrition. Frequently tried pharmacological interventions, such as ribavirin, nebulized bronchodilators, and systemic corticosteroids, have not been proven to benefit patients with bronchiolitis. Antibiotics do not improve the clinical course of patients with bronchiolitis, and should be used only in those patients with proven concurrent bacterial infection. Exogenous surfactant and heliox therapy also cannot be recommended for routine use, but surfactant replacement holds promise and should be further studied.

Respiratory syncytial virus prevention and therapy: past, present, and future

Respiratory syncytial virus (RSV) is the most common respiratory pathogen in infants and young children worldwide. More than 50 years after its discovery, and despite relentless attempts to identify pharmacological therapies to improve the clinical course and outcomes of this disease, the most effective therapy remains supportive care. Although the quest for a safe and effective vaccine remains unsuccessful, pediatricians practicing during the past decade have been able to protect at least the more vulnerable patients with safe and effective passive prophylaxis. This review summarizes the history, microbiology, epidemiology, pathophysiology, and clinical manifestations of this infection in order to provide the reader with the background information necessary to fully appreciate the many challenges presented by the clinical management of young children with bronchiolitis. The last part of this article attempts an evidence-based review of the pharmacologic strategies currently available and those being evaluated, intentionally omitting highly experimental approaches not yet tested in clinical trials and, therefore, not likely to become available in the foreseeable future.

Local cytokine response upon respiratory syncytial virus infection

Respiratory syncytial virus (RSV) is the leading cause of childhood hospitalization and respiratory distress and has been recognized for several decades as a major health and economic burden worldwide. This virus has developed several virulence mechanisms to impair the establishment of a protective immune response to re-infection. Accordingly, inefficient immunological memory is usually generated after exposure to this pathogen. Furthermore, it has been shown that RSV can actively promote the induction of an inadequate cellular immune response at the site of infection that causes exacerbated inflammation in the respiratory tract. Such an inflammatory response is both inefficient for clearing the virus and can be responsible for detrimental symptoms, such as asthma and wheezing. Recent data suggest that RSV possesses molecular mechanisms to induce the secretion of pro-inflammatory cytokines that modulate the immune response and impair viral clearance by reducing IFN-γ production. Here, we discuss recent research leading to the identification of RSV virulence factors that are responsible of promoting a pro-inflammatory environment at the airways and their implications on pathogenicity.

WITHDRAWN: Ribavirin for respiratory syncytial virus infection of the lower respiratory tract in infants and young children

BACKGROUND

Respiratory syncytial virus (RSV) is a common cause of lower respiratory tract infection in infants and is responsible for many hospitalizations annually. Ribavirin is approved for treatment of these infections, but its use is controversial because of questions about its efficacy, concerns about occupational exposure, and its high cost.

OBJECTIVES

The objective of this review is to assess the efficacy of aerosolized ribavirin for infants and children with lower respiratory tract infection due to RSV.

SEARCH STRATEGY

We performed an updated electronic search of the Cochrane Central Register of Controlled Trials (CENTRAL), the Database of Abstracts of Reviews of Effects (DARE) and the NHS Economic Evaluation Database (EED) (The Cochrane Library 2006, issue 3) which contains the Acute Respiratory Infections Group's specialized register; MEDLINE (Ovid) (2004 to September Week 3 2006); and EMBASE (WebSpirs) (2004 to June 2006).

SELECTION CRITERIA

Randomized trials comparing ribavirin with placebo in infants and children with lower respiratory tract infection attributable to RSV.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed trial quality. Unpublished data were requested from trial authors when necessary.

MAIN RESULTS

Twelve trials were included. All trials enrolled infants below the age of six months. In four trials with 158 participants, mortality with ribavirin was 5.8% compared with 9.7% with placebo (odds ratio (OR) 0.58; 95% confidence interval (CI) 0.18 to 1.85). In three trials with 116 participants the probability of respiratory deterioration with ribavirin was 7.1% compared with 18.3% with placebo (OR 0.37; 95% CI 0.12 to 1.18). In three studies with 104 ventilated participants, the mean difference in days of hospitalization was 1.9 fewer days with ribavirin (95% CI -4.6 to +0.9) and the mean difference in days of ventilation was 1.8 fewer days with ribavirin (95% CI -3.4 to -0.2). No statistically significant differences in long-term pulmonary function or in incidence of recurrent wheezing following RSV infection were associated with the use of ribavirin.

AUTHORS' CONCLUSIONS

Trials of ribavirin for RSV lack sufficient power to provide reliable estimates of the effects. The cumulative results of three small trials show that ribavirin may reduce the duration of mechanical ventilation and may reduce days of hospitalization. In addition, use of ribavirin may be associated with a decrease in the long-term incidence of recurrent wheezing following RSV disease. A large randomized controlled trial of ribavirin for ventilated and other high-risk participants is indicated.

Ribavirin for respiratory syncytial virus infection of the lower respiratory tract in infants and young children

BACKGROUND

Respiratory syncytial virus (RSV) is a common cause of lower respiratory tract infection in infants and is responsible for many hospitalizations annually. Ribavirin is approved for treatment of these infections, but its use is controversial because of questions about its efficacy, concerns about occupational exposure, and its high cost.

OBJECTIVES

The objective of this review is to assess the efficacy of aerosolized ribavirin for infants and children with lower respiratory tract infection due to RSV.

SEARCH STRATEGY

We performed an updated electronic search of the Cochrane Central Register of Controlled Trials (CENTRAL), the Database of Abstracts of Reviews of Effects (DARE) and the NHS Economic Evaluation Database (EED) (The Cochrane Library Issue 3, 2006); MEDLINE (Ovid) (2004 to September Week 3 2006); and EMBASE (WebSpirs) (2004 to June 2006).

SELECTION CRITERIA

Randomized trials comparing ribavirin with placebo in infants and children with lower respiratory tract infection attributable to RSV.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed trial quality. Unpublished data were requested from trial authors when necessary.

MAIN RESULTS

Twelve trials were included. All trials enrolled infants below the age of six months. In four trials with 158 participants, mortality with ribavirin was 5.8% compared with 9.7% with placebo (odds ratio (OR) 0.58; 95% confidence interval (CI) 0.18 to 1.85). In three trials with 116 participants the probability of respiratory deterioration with ribavirin was 7.1% compared with 18.3% with placebo (OR 0.37; 95% CI 0.12 to 1.18). In three studies with 104 ventilated participants, the mean difference in days of hospitalization was 1.9 fewer days with ribavirin (95% CI -4.6 to +0.9) and the mean difference in days of ventilation was 1.8 fewer days with ribavirin (95% CI -3.4 to -0.2). No statistically significant differences in long-term pulmonary function or in incidence of recurrent wheezing following RSV infection were associated with the use of ribavirin.

AUTHORS' CONCLUSIONS

Trials of ribavirin for RSV lack sufficient power to provide reliable estimates of the effects. The cumulative results of three small trials show that ribavirin may reduce the duration of mechanical ventilation and may reduce days of hospitalization. In addition, use of ribavirin may be associated with a decrease in the long-term incidence of recurrent wheezing following RSV disease. A large randomized controlled trial of ribavirin for ventilated and other high-risk participants is indicated.

Diagnosis and management of bronchiolitis

Bronchiolitis is a disorder most commonly caused in infants by viral lower respiratory tract infection. It is the most common lower respiratory infection in this age group. It is characterized by acute inflammation, edema, and necrosis of epithelial cells lining small airways, increased mucus production, and bronchospasm. The American Academy of Pediatrics convened a committee composed of primary care physicians and specialists in the fields of pulmonology, infectious disease, emergency medicine, epidemiology, and medical informatics. The committee partnered with the Agency for Healthcare Research and Quality and the RTI International-University of North Carolina Evidence-Based Practice Center to develop a comprehensive review of the evidence-based literature related to the diagnosis, management, and prevention of bronchiolitis. The resulting evidence report and other sources of data were used to formulate clinical practice guideline recommendations. This guideline addresses the diagnosis of bronchiolitis as well as various therapeutic interventions including bronchodilators, corticosteroids, antiviral and antibacterial agents, hydration, chest physiotherapy, and oxygen. Recommendations are made for prevention of respiratory syncytial virus infection with palivizumab and the control of nosocomial spread of infection. Decisions were made on the basis of a systematic grading of the quality of evidence and strength of recommendation. The clinical practice guideline underwent comprehensive peer review before it was approved by the American Academy of Pediatrics. This clinical practice guideline is not intended as a sole source of guidance in the management of children with bronchiolitis. Rather, it is intended to assist clinicians in decision-making. It is not intended to replace clinical judgment or establish a protocol for the care of all children with this condition. These recommendations may not provide the only appropriate approach to the management of children with bronchiolitis.

Ribavirin for respiratory syncytial virus infection of the lower respiratory tract in infants and young children

BACKGROUND

Respiratory syncytial virus (RSV) is a common cause of lower respiratory tract infection in infants and is responsible for 100,000 hospitalizations annually. Ribavirin is approved for treatment of these infections, but its use is controversial because of questions about its efficacy, concerns about occupational exposure, and its high cost.

OBJECTIVES

The objective of this review is to assess the efficacy of aerosolized ribavirin for infants and children with lower respiratory tract infection due to RSV.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, Issue 1, 2004), MEDLINE (January 1975 to January week 3, 2004) and EMBASE (January 1990 to December 2003). We scanned reference lists of articles and contacted experts in the field.

SELECTION CRITERIA

Randomized trials comparing ribavirin with placebo in infants and children with RSV infection and lower respiratory tract infection.

DATA COLLECTION AND ANALYSIS

Two reviewers independently extracted data and assessed trial quality. Unpublished data were requested from authors when necessary.

MAIN RESULTS

Twelve trials were included. All trials enrolled infants below the age of six months. In four trials with 158 patients, mortality with ribavirin was 5.8% compared with 9.7% with placebo (odds ratio (OR) 0.58; 95% confidence interval (CI) 0.18 to 1.85). In three trials with 116 patients the probability of respiratory deterioration with ribavirin was 7.1% compared with 18.3% with placebo (OR 0.37; 95% CI 0.12 to 1.18). In three studies with 104 ventilated patients, the weighted mean difference in days of hospitalization was 1.9 fewer days with ribavirin (95% CI -4.6 to +0.9) and the weighted mean difference in days of ventilation was 1.8 fewer days with ribavirin (95% CI -3.4 to -0.2). No statistically significant differences in long-term pulmonary function or in incidence of recurrent wheezing following RSV infection were associated with the use of ribavirin.

REVIEWERS' CONCLUSIONS

Trials of ribavirin for RSV lack sufficient power to provide reliable estimates of the effects. The cumulative results of three small trials show that ribavirin may reduce the duration of mechanical ventilation and may reduce days of hospitalization. In addition, use of ribavirin may be associated with a decrease in the long-term incidence of recurrent wheezing following RSV disease. A large randomized controlled trial of ribavirin for ventilated and other high-risk patients is indicated.

Coronavirus replication and pathogenesis: Implications for the recent outbreak of severe acute respiratory syndrome (SARS), and the challenge for vaccine development

A novel coronavirus has been recently identified as the causative agent of the severe acute respiratory syndrome (SARS) outbreak that has accounted for more than 8000 infected people worldwide. This review will discuss current knowledge on coronavirus replication, pathogenesis, evolution, and vaccine strategies, as well as the most recent findings on SARS coronavirus.

Effectiveness of drug therapies to treat or prevent respiratory syncytial virus infection-related morbidity

Respiratory syncytial virus (RSV) infection causes a huge burden to the health service, as it results in a large number of in-patient days each year and increases the risk of asthma in childhood. In the acute phase, therapy is supportive as bronchodilators and corticosteroids have resulted, at best, only in short-term benefits; promising treatments for ventilated patients, such as exogenous surfactant, require further testing. Passive immunoprophylaxis reduces hospital admission in high risk groups. In the prevention of chronic respiratory morbidity following RSV infection, however, studies are needed to determine whether immunoprophylaxis will have a useful role and to identify which drug treatment will be most cost-effective.

Inhalation therapy for infants

Delivering aerosolised drugs to infants poses a number of challenges. It is clear that drug delivery is possible via the inhaled route but to date it has been difficult to demonstrate clearly therapeutic benefit from the use of any conventional therapy in the vast majority of infants. This is probably related to the nature of pulmonary disease in this age group. While most aerosol scientists focus on factors such as aerosol size and airways geometry drug delivery, as in all age groups, is most dependent upon patient behaviour. A small amount of drug reaches the lungs of distressed infants. Consideration of patient device interactions is vital if successful drug delivery is to be achieved and this includes consideration of mask design. Doses reaching the lungs are generally very low when considered in terms of the nominal dose but when considered in terms of dose delivered per kilogram body weight drug delivery to the lungs is generally similar to or greater than in adults. Upper airways deposition is relatively greater than in older subjects, in large part because of nasal breathing, and this will affect the 'therapeutic index' of some drugs.

Bronchiolitis: update 2001

In this review, reports from last year on the following topics are summarized: (1) reviews of bronchiolitis in infants; respiratory syncytial virus (RSV)-associated illness, including possible viral mechanisms of alteration of airway function and results of an epidemiologic study of bronchiolitis-associated mortality. Studies evaluating (2) the use of serum eosinophilic cationic protein as a marker for development of subsequent persistent wheezing infants; (3) parental bronchial responsiveness as an indicator of genetic susceptibility to acute bronchiolitis; (4) prophylactic use of monoclonal antibody (Palivizumab) to control an outbreak of RSV in a hospital nursery; (5) a controlled clinical trial of ribaviron in acutely ill children; (6) reports of new associations with bronchiolitis obliterans organizing pneumonia (BOOP); (7) case reports of use of methotrexate as an alternate to corticosteroids in treatment of BOOP; (8) a newly described entity, eosinophilic bronchiolitis.