Anticipated costs of hospitalization for respiratory syncytial virus infection in young children at risk

Hyperoxia-induced airflow restriction and Renin-Angiotensin System expression in a bronchopulmonary dysplasia mouse model

Mechanisms underlying hyperoxia-induced airflow restriction in the pediatric lung disease Bronchopulmonary dysplasia (BPD) are unclear. We hypothesized a role for Renin-Angiotensin System (RAS) activity in BPD. RAS is comprised of a pro-developmental pathway consisting of angiotensin converting enzyme-2 (ACE2) and angiotensin II receptor type 2 (AT2), and a pro-fibrotic pathway mediated by angiotensin II receptor type 1 (AT1). We investigated associations between neonatal hyperoxia, airflow restriction, and RAS activity in a BPD mouse model. C57 mouse pups were randomized to normoxic (FiO2  = 0.21) or hyperoxic (FiO2  = 0.75) conditions for 15 days (P1-P15). At P15, P20, and P30, we measured airflow restriction using plethysmography and ACE2, AT1, and AT2 mRNA and protein expression via polymerase chain reaction and Western Blot. Hyperoxia increased airflow restriction P15 and P20, decreased ACE2 and AT2 mRNA, decreased AT2 protein, and increased AT1 protein expression. ACE2 mRNA and protein remained suppressed at P20. By P30, airflow restriction and RAS expression did not differ between groups. Hyperoxia caused high airflow restriction, increased pulmonary expression of the pro-fibrotic RAS pathway, and decreased expression of the pro-developmental in our BPD mouse model. These associated findings may point to a causal role for RAS in hyperoxia-induced airflow restriction.

Respiratory Syncytial Virus: A Systematic Review and Meta-Analysis of Tomographic Findings (2000-2022)

Human respiratory syncytial virus (RSV) is a main cause of medical referrals and hospitalizations in all infants, particularly among newborns. Nevertheless, relatively limited evidence on chest tomography (CT) findings has been collected. According to the PRISMA statement, Pubmed, Embase, and medRxiv were searched for eligible observational studies published up to 31 December 2022. Cases were categorized in children and adolescents (age < 18 years), adults and elderly (age ≥ 18 years), and immunocompromised patients, and then pooled in a random-effects model. Heterogeneity was assessed using the I2 statistics, while reporting bias was assessed by means of funnel plots and regression analysis. A total of 10 studies (217 RSV cases) were retrieved (children, 37.3%; immunocompromised, 41.0%; adults, 21.7%). The most common features were signs of organizing pneumonia (33.65%, 95% confidence interval [95% CI] 22.39-47.27), followed by septal thickening (33.19%, 95% CI 21.76-47.03), ground glass opacities (GGOs; 28.03%, 95% CI 14.69-46.82), and tree-in-bud (TIB, 27.44%, 95% CI 15.04-44.68). Interestingly, up to 16.23% (95% CI 8.17-29.69) showed normal findings, while the large majority (76.06%, 95% CI 64.81-84.56) were characterized by bilateral involvement. Studies were highly heterogeneous without substantial reporting bias. Assuming children and adolescents as reference groups, healthy adults were characterized by a higher risk ratio [RR] for septal thickening (RR 3.878, 95% CI 1.253-12.000), nodular lesions (RR 20.197, 95% CI 1.286-317.082), and GGOs (RR 2.121, 95% CI 1.121-4.013). RSV cases are rarely assessed in terms of CT characteristics. Our study identified some specificities, suggesting that RSV infections evolve heterogeneous CT features in children/adolescents and adults, but the paucity of studies recommends a cautious appraisal.

Analysing the protection from respiratory tract infections and allergic diseases early in life by human milk components: the PRIMA birth cohort

Background

Many studies support the protective effect of breastfeeding on respiratory tract infections. Although infant formulas have been developed to provide adequate nutritional solutions, many components in human milk contributing to the protection of newborns and aiding immune development still need to be identified. In this paper we present the methodology of the “Protecting against Respiratory tract lnfections through human Milk Analysis” (PRIMA) cohort, which is an observational, prospective and multi-centre birth cohort aiming to identify novel functions of components in human milk that are protective against respiratory tract infections and allergic diseases early in life.

Methods

For the PRIMA human milk cohort we aim to recruit 1000 mother–child pairs in the first month postpartum. At one week, one, three, and six months after birth, fresh human milk samples will be collected and processed. In order to identify protective components, the level of pathogen specific antibodies, T cell composition, Human milk oligosaccharides, as well as extracellular vesicles (EVs) will be analysed, in the milk samples in relation to clinical data which are collected using two-weekly parental questionnaires. The primary outcome of this study is the number of parent-reported medically attended respiratory infections. Secondary outcomes that will be measured are physician diagnosed (respiratory) infections and allergies during the first year of life.

Discussion

The PRIMA human milk cohort will be a large prospective healthy birth cohort in which we will use an integrated, multidisciplinary approach to identify the longitudinal effect human milk components that play a role in preventing (respiratory) infections and allergies during the first year of life. Ultimately, we believe that this study will provide novel insights into immunomodulatory components in human milk. This may allow for optimizing formula feeding for all non-breastfed infants.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07107-w.

Health care costs of hospitalization of young children for respiratory syncytial virus infections: a population-based matched cohort study

BACKGROUND

Respiratory syncytial virus (RSV) infection poses a substantial clinical burden among infants and young children. We sought to determine the health care costs of hospitalizations attributable to RSV in Ontario, Canada, from the health care payer perspective.

METHODS

For this population-based matched cohort study, we identified children younger than 24 months who were or were not hospitalized with RSV infections in 2006-2016. We performed a cost-of-illness analysis using linked administrative health data, with subjects stratified by gestational age and congenital heart disease, and propensity score-matched on established risk factors. The primary outcome was attributable health care costs per patient, reflecting the difference in direct medical costs between the groups, calculated to 12 months postdischarge in 2020 Canadian dollars.

RESULTS

We identified 14 608 RSV-infected children, matched to 72 040 controls. The adjusted attributable cost of hospitalized RSV was $134 931 900 over 10 years, or $9240 per patient (95% confidence interval [CI] $8790-$9690). Health care costs escalated 3 days before hospitalization, and persisted up to 12 months after discharge. Increased costs were associated with major comorbidities, but not extreme premature birth. The highest mean attributable cost per patient was in the presence of hemodynamically significant heart disease ($60 110, 95% CI $26 700-$93 060). Infants born at 36-43 weeks' gestation constituted the greatest overall cost burden at $117 886 720.

INTERPRETATION

Although the greatest direct medical costs per patient hospitalized with RSV infection are among children with cardiac disease, the greatest overall cost burden is from children born at or near term, who are not targeted by current prophylaxis strategies. The substantial attributable health care costs of RSV can inform cost-effectiveness analyses of novel RSV vaccines and prioritization of health care resources.

Assessment of the Effects of Active Immunisation against Respiratory Syncytial Virus (RSV) using Decision-Analytic Models: A Systematic Review with a Focus on Vaccination Strategies, Modelling Methods and Input Data

BACKGROUND

Several vaccine and antibody candidates are currently in development for the prevention of lower respiratory tract infections caused by the respiratory syncytial virus (RSV).

METHODS

We searched MEDLINE, Embase, and SCOPUS and included model-based evaluations of RSV vaccinations. Two reviewers performed the selection, data extraction, and quality evaluation with EVIDEM. Cost-effectiveness (CE) estimates were converted to $US purchasing power parity (PPP), year 2018 values. Potential economic and epidemiological outcomes were summarised for maternal, infant, children, and elderly vaccinations. The PROSPERO identifier is CRD42019122570.

RESULTS

In total, 22 model-based studies were reviewed. On average, a potential 27% reduction in RSV hospitalisations in infants was projected for maternal vaccination and 50% for direct infant immunisation. The CE of maternal vaccination was $US1766-5857 PPP 2018/disability-adjusted life-years (DALYs) for Global Alliance for Vaccines and Immunisation (Gavi)-eligible countries. For England, the maximum cost-effective price of maternal vaccination was estimated at $US81.5 PPP 2018. Infant vaccination was associated with higher CE ratios in low- and high-income settings. Vaccination of neonates born before the RSV season was the most cost effective in high-income settings. Higher values for vaccine effectiveness, duration of protection, and vaccine uptake increased the benefits. Due to indirect effects, the vaccination of school-age children and a cocooning strategy were effective alternatives to protect infants, and the vaccination of children aged < 5 years had a beneficial impact on the elderly.

CONCLUSION

RSV vaccines with anticipated characteristics may reduce a sizeable proportion of the RSV burden. The results are subject to uncertainty because of the limited epidemiological and clinical data. Data on RSV incidence and hospitalisation risk for granular age strata should be prioritised to facilitate the evaluation of RSV interventions and decision making.

Burden of prematurity-associated recurrent wheezing: caregiver missed work in the D-Wheeze trial

OBJECTIVE

This study describes the burden of prematurity-associated wheezing in black infants with respect to caregiver missed work.

STUDY DESIGN

We analyzed data from the D-Wheeze trial (ClinicalTrials.gov identifier NCT01601847). Black infants between 28-0/7 to 36-6/7 weeks' gestational age at birth receiving <28 days of supplemental oxygen were enrolled. The primary outcome was missed work to care for the infant in the first year.

RESULTS

147/277 (53.1%) infants had caregivers who reported time off. In an adjusted model, vitamin D supplementation (OR 0.52 [95% CI 0.30-0.89]; P = 0.018), recurrent wheeze (OR 2.26 [95% CI, 1.15-4.44]; P = 0.018), and other children in the household <5 years old (OR 0.45 [95% CI 0.26-0.78]; P = 0.004) were significantly associated with caregiver missed work.

CONCLUSIONS

Black premature infants had a significant burden of caregiver missed work, emphasizing the impact of prematurity-associated wheezing.

Cost Study of a Cluster Randomized Trial on a Clinical Decision Rule Guiding Antibiotic Treatment in Children With Suspected Lower Respiratory Tract Infections in the Emergency Department

BACKGROUND

Children with fever and respiratory symptoms represent a large patient group at the emergency department (ED). A decision rule-based treatment strategy improved targeting of antibiotics in these children in a recent clinical trial. This study aims to evaluate the impact of the decision rule on healthcare and societal costs, and to describe costs of children with suspected lower respiratory tract infections (RTIs) in the ED in general.

METHODS

In a stepped-wedge, cluster randomized trial, we collected cost data of children 1 month to 5 years of age with fever and cough/dyspnea in 8 EDs in The Netherlands (2016-2018). We calculated medical costs and societal costs per patient, during usual care (n = 597), and when antibiotic prescription was guided by the decision rule (n = 402). We calculated cost-of-illness of this patient group and estimated their annual costs at national level.

RESULTS

The cost-of-illness of children under 5 years with suspected lower RTIs in the ED was on average &OV0556;2130 per patient. At population level this is &OV0556;15 million per year in The Netherlands (&OV0556;1.7 million/100,000 children under 5). Mean costs per patient in usual care (&OV0556;2300) were reduced to &OV0556;1870 in the intervention phase (P = 0.01). Main cost drivers were hospitalization and lost parental workdays.

CONCLUSIONS

Implementation of a decision rule-based treatment strategy in children with suspected lower RTI was cost-saving, due to a reduction in hospitalization and parental absenteeism. Given the high frequency of this disease in children, the decision rule has the potential to result in a considerable cost reduction at population level.

Cost of Respiratory Syncytial Virus-Associated Acute Lower Respiratory Infection Management in Young Children at the Regional and Global Level: A Systematic Review and Meta-Analysis

Background

Respiratory syncytial virus (RSV) is a major cause of acute lower respiratory infection (ALRI) in young children aged &lt;5 years.

Methods

We aimed to identify the global inpatient and outpatient cost of management of RSV-ALRI in young children to assist health policy makers in making decisions related to resource allocation for interventions to reduce severe morbidity and mortality from RSV in this age group. We searched 3 electronic databases including Global Health, Medline, and EMBASE for studies reporting cost data on RSV management in children under 60 months from 2000 to 2017. Unpublished data on the management cost of RSV episodes were collected through collaboration with an international working group (RSV GEN) and claim databases.

Results

We identified 41 studies reporting data from year 1987 to 2017, mainly from Europe, North America, and Australia, covering the management of a total of 365 828 RSV disease episodes. The average cost per episode was €3452 (95% confidence interval [CI], 3265–3639) and €299 (95% CI, 295–303) for inpatient and outpatient management without follow-up, and it increased to €8591(95% CI, 8489–8692) and €2191 (95% CI, 2190–2192), respectively, with follow-up to 2 years after the initial event.

Conclusions

Known risk factors (early and late preterm birth, congenital heart disease, chronic lung disease, intensive care unit admission, and ventilator use) were associated with €4160 (95% CI, 3237–5082) increased cost of hospitalization. The global cost of inpatient and outpatient RSV ALRI management in young children in 2017 was estimated to be approximately €4.82 billion (95% CI, 3.47–7.93), 65% of these in developing countries and 55% of global costs accounted for by hospitalization. We have demonstrated that RSV imposed a substantial economic burden on health systems, governments, and the society.

Cost-effectiveness of rule-based immunoprophylaxis against respiratory syncytial virus infections in preterm infants

The objective of the paper is to assess the cost-effectiveness of targeted respiratory syncytial virus (RSV) prophylaxis based on a validated prediction rule with 1-year time horizon in moderately preterm infants compared to no prophylaxis. Data on health care consumption were derived from a randomised clinical trial on wheeze reduction following RSV prophylaxis and a large birth cohort study on risk prediction of RSV hospitalisation. We calculated the incremental cost-effectiveness ratio (ICER) of targeted RSV prophylaxis vs. no prophylaxis per quality-adjusted life year (QALYs) using a societal perspective, including medical and parental costs and effects. Costs and health outcomes were modelled in a decision tree analysis with sensitivity analyses. Targeted RSV prophylaxis in infants with a first-year RSV hospitalisation risk of > 10% resulted in a QALY gain of 0.02 (0.931 vs. 0.929) per patient against additional cost of €472 compared to no prophylaxis (ICER €214,748/QALY). The ICER falls below a threshold of €80,000 per QALY when RSV prophylaxis cost would be lowered from €928 (baseline) to €406 per unit. At a unit cost of €97, RSV prophylaxis would be cost saving.

CONCLUSIONS

Targeted RSV prophylaxis is not cost-effective in reducing RSV burden of disease in moderately preterm infants, but it can become cost-effective if lower priced biosimilar palivizumab or a vaccine would be available.

Defining the Risk and Associated Morbidity and Mortality of Severe Respiratory Syncytial Virus Infection Among Infants with Chronic Lung Disease

INTRODUCTION

The REGAL (RSV evidence-a geographical archive of the literature) series provide a comprehensive review of the published evidence in the field of respiratory syncytial virus (RSV) in Western countries over the last 20 years. This third publication covers the risk and burden of RSV infection in infants with chronic lung disease (CLD), formerly called bronchopulmonary dysplasia (BPD).

METHODS

A systematic review was undertaken of publications between January 1, 1995 and December 31, 2015 across PubMed, Embase, The Cochrane Library, and Clinicaltrials.gov. Studies reporting data for hospital visits/admissions for RSV infection among infants with CLD/BPD who were not prophylaxed, as well as studies reporting RSV-associated morbidity, mortality, and healthcare costs, were included. Burdens of disease data were compared with preterm infants without CLD/BPD, other high-risk groups and term infants. Study quality and strength of evidence (SOE) were graded using recognized criteria.

RESULTS

A total of 1837 studies were identified and 39 were included. CLD/BPD is a significant independent risk factor for RSV hospitalization [RSVH (odds ratio 2.2-7.2); high SOE]. Infants and young children with CLD/BPD had high RSVH rates which were generally similar in Europe, the United States, and Canada, mostly varying between 12 and 21%. Infants with CLD also had a longer length of hospital stay than other high-risk groups and term infants (high SOE). On average, infants spent 4-11 days in hospital (moderate SOE). Once hospitalized for RSV, affected children were at risk for a more severe course of disease than children with no RSVH (moderate SOE).

CONCLUSION

Severe RSV infection in infants and young children with CLD/BPD poses a significant health burden in Western countries. Further studies focussing on the burden of RSV infection in this well-recognized population at high risk for severe disease are needed to help improve outcomes and plan allocation of healthcare resources.

FUNDING

AbbVie.

Defining the Risk and Associated Morbidity and Mortality of Severe Respiratory Syncytial Virus Infection Among Preterm Infants Without Chronic Lung Disease or Congenital Heart Disease

INTRODUCTION

The REGAL (RSV Evidence-a Geographical Archive of the Literature) series provide a comprehensive review of the published evidence in the field of respiratory syncytial virus (RSV) in Western countries over the last 20 years. This second publication covers the risk and burden of RSV infection in preterm infants born at <37 weeks' gestational age (wGA) without chronic lung disease or congenital heart disease.

METHODS

A systematic review was undertaken for articles published between January 1, 1995 and December 31, 2015. Studies reporting data for hospital visits/admissions for RSV infection among preterm infants as well as studies reporting RSV-associated morbidity, mortality, and risk factors were included. Study quality and strength of evidence (SOE) were graded using recognized criteria.

RESULTS

2469 studies were identified of which 85 were included. Preterm infants, particularly those born at lower wGA, tended to have higher RSV hospitalization (RSVH) rates compared with otherwise healthy term infants (high SOE). RSVH rates ranged from ~5 per 1000 children to >100 per 1000 children with the highest rates shown in the lowest gestational age infants (high SOE). Independent risk factors associated with RSVH include: proximity of birth to the RSV season, living with school-age siblings, smoking of mother during pregnancy or infant exposure to environmental smoking, reduced breast feeding, male sex, and familial atopy (asthma) (high SOE). Predictive models can identify 32/33-35 wGA infants at risk of RSVH (high SOE).

CONCLUSION

RSV infection remains a major burden on Western healthcare systems and is associated with significant morbidity. Further studies focusing on the prevalence and burden of RSV in different gestational age cohorts, the changing risk of RSVH during the first year of life, and on RSV-related mortality in preterm infants are needed to determine the true burden of disease.

FUNDING

AbbVie.

Prediction model of RSV-hospitalization in late preterm infants: An update and validation study

BACKGROUND

New vaccines and RSV therapeutics have been developed in the past decade. With approval of these new pharmaceuticals on the horizon, new challenges lie ahead in selecting the appropriate target population. We aimed to improve a previously published prediction model for prediction of RSV-hospitalization within the first year of life.

METHODS

Two consecutive prospective multicenter birth cohort studies were performed from June 2008 until February 2015. The first cohort (RISK-I, n=2524, 2008-2011) was used to update the existing model. The updated model was subsequently validated in the RISK-II cohort (n=1564, 2011-2015). We used the TRIPOD criteria for transparent reporting.

RESULTS

181 infants (n=127 in RISK-I, n=54 in RISK-II) were hospitalized for RSV within their first year of life. The updated model included the following predictors; day care attendance and/or siblings (OR: 5.3; 95% CI 2.8-10.1), birth between Aug. 14th and Dec. 1st (OR: 2.4; 1.8-3.2), neonatal respiratory support (OR 2.2; 1.6-3.0), breastfeeding ≤4 months (OR 1.6; 1.2-2.2) and maternal atopic constitution (OR 1.5; 1.1-2.1). The updated models' discrimination was superior to the original model in the RISK-II cohort (AUROC 0.72 95% CI 0.65-0.78 versus AUROC 0.66, 95% CI 0.60-0.73, respectively). The updated model was translated into a simple nomogram to be able to distinguish infants with high versus low risk of RSV-hospitalization.

CONCLUSION

We developed and validated a clinical prediction model to be able to predict RSV-hospitalization in preterm infants born within 32-35 weeks gestational age. A simple nomogram was developed to target RSV therapeutics to those children who will benefit the most.

A systematic review of predictive modeling for bronchiolitis

PURPOSE

Bronchiolitis is the most common cause of illness leading to hospitalization in young children. At present, many bronchiolitis management decisions are made subjectively, leading to significant practice variation among hospitals and physicians caring for children with bronchiolitis. To standardize care for bronchiolitis, researchers have proposed various models to predict the disease course to help determine a proper management plan. This paper reviews the existing state of the art of predictive modeling for bronchiolitis. Predictive modeling for respiratory syncytial virus (RSV) infection is covered whenever appropriate, as RSV accounts for about 70% of bronchiolitis cases.

METHODS

A systematic review was conducted through a PubMed search up to April 25, 2014. The literature on predictive modeling for bronchiolitis was retrieved using a comprehensive search query, which was developed through an iterative process. Search results were limited to human subjects, the English language, and children (birth to 18 years).

RESULTS

The literature search returned 2312 references in total. After manual review, 168 of these references were determined to be relevant and are discussed in this paper. We identify several limitations and open problems in predictive modeling for bronchiolitis, and provide some preliminary thoughts on how to address them, with the hope to stimulate future research in this domain.

CONCLUSIONS

Many problems remain open in predictive modeling for bronchiolitis. Future studies will need to address them to achieve optimal predictive models.

Prospective validation of a prognostic model for respiratory syncytial virus bronchiolitis in late preterm infants: a multicenter birth cohort study

OBJECTIVES

This study aimed to update and validate a prediction rule for respiratory syncytial virus (RSV) hospitalization in preterm infants 33-35 weeks gestational age (WGA).

STUDY DESIGN

The RISK study consisted of 2 multicenter prospective birth cohorts in 41 hospitals. Risk factors were assessed at birth among healthy preterm infants 33-35 WGA. All hospitalizations for respiratory tract infection were screened for proven RSV infection by immunofluorescence or polymerase chain reaction. Multivariate logistic regression analysis was used to update an existing prediction model in the derivation cohort (n = 1,227). In the validation cohort (n = 1,194), predicted versus actual RSV hospitalization rates were compared to determine validity of the model.

RESULTS

RSV hospitalization risk in both cohorts was comparable (5.7% versus 4.9%). In the derivation cohort, a prediction rule to determine probability of RSV hospitalization was developed using 4 predictors: family atopy (OR 1.9; 95%CI, 1.1-3.2), birth period (OR 2.6; 1.6-4.2), breastfeeding (OR 1.7; 1.0-2.7) and siblings or daycare attendance (OR 4.7; 1.7-13.1). The model showed good discrimination (c-statistic 0.703; 0.64-0.76, 0.702 after bootstrapping). External validation showed good discrimination and calibration (c-statistic 0.678; 0.61-0.74).

CONCLUSIONS

Our prospectively validated prediction rule identifies infants at increased RSV hospitalization risk, who may benefit from targeted preventive interventions. This prediction rule can facilitate country-specific, cost-effective use of RSV prophylaxis in late preterm infants.

Palivizumab in preventing respiratory syncytial virus-related hospitalization in high-risk infants

Respiratory syncytial virus (RSV) causes seasonal epidemics (winter or wet-season) of serious lower respiratory tract infections in young infants with subsequent increased frequency of recurrent wheezing during early childhood. Palivizumab is a humanized monoclonal antibody that provides immunoprophylaxis against RSV when administered monthly over the RSV season. It significantly reduced hospitalizations in high-risk infants including preterm infants with and without bronchopulmonary dysplasia and infants with hemodynamically significant congenital heart disease. Since its license in 1998, approximately 36 methodologically different economic studies have been performed to prove cost-effectiveness of the product. The majority of cost-effectiveness analyses revealed costs of palivizumab exceeding anticipated savings from reduced RSV hospitalizations. A minority of studies performed cost-effectiveness analyses using incremental cost-effectiveness ratios as costs per quality-adjusted life-year gained. The wide variability in the results of economic studies with estimates ranging from cost savings to incremental costs of a high order of magnitude with its use is discussed, in the light of the continuing burden of RSV disease, the limited treatment modalities, and the continuing research for a vaccine.

Cost-effectiveness of potential infant vaccination against respiratory syncytial virus infection in The Netherlands

INTRODUCTION

Respiratory syncytial virus (RSV) infection is one of the major causes of respiratory illness in infants, infecting virtually every child before the age of 2 years. Currently, several Phase 1 trials with RSV vaccines in infants are ongoing or have been completed. As yet, no efficacy estimates are available for these vaccine candidates. Nevertheless, cost-effectiveness estimates might be informative to enable preliminary positioning of an RSV vaccine.

METHODS

A decision analysis model was developed in which a Dutch birth cohort was followed for 12 months. A number of potential vaccination strategies were reviewed such as vaccination at specific ages, a two- or three-dosing scheme and seasonal vaccination versus year-round vaccination. The impact of the assumptions made was explored in various sensitivity analyses, including probabilistic analysis. Outcome measures included the number of GP visits, hospitalizations and deaths, costs, quality-adjusted life years and incremental cost-effectiveness ratios (ICERs).

RESULTS

Currently, without vaccination, an annual number of 28,738 of RSV-related GP visits, 1623 hospitalizations, and 4.5 deaths are estimated in children in the age of 0-1 year. The total annual cost to society of RSV in the non-vaccination scenario is €7.7 million (95%CI: 1.7-16.7) and the annual disease burden is estimated at 597 QALYs (95%CI: 133-1319). In case all infants would be offered a potentially safe and effective 3-dose RSV vaccination scheme at the age of 0, 1 and 3 months, the total annual net costs were estimated to increase to €21.2 million, but 544 hospitalizations and 1.5 deaths would be averted. The ICER was estimated at €34,142 (95%CI: € 21,652-€ 87,766) per QALY gained. A reduced dose schedule, seasonal vaccination, and consideration of out-of-pocket expenses all resulted in more favorable ICER values, whereas a reduced vaccine efficacy or a delay in the timing of vaccination resulted in less favorable ICERs.

DISCUSSION

Our model used recently updated estimates on the burden of RSV disease in children and it included plausible utilities. However, due to the absence of clinical trial data, a number of crucial assumptions had to be made related to the characteristics of potential RSV vaccine. The outcomes of our modeling exercise show that vaccination of infants against RSV might be cost-effective. However, clinical trial data are warranted.

Clinical impact of RT-PCR for pediatric acute respiratory infections: a controlled clinical trial

OBJECTIVE

Real-time polymerase chain reaction (RT-PCR) testing is a quick sensitive method for detecting respiratory pathogens. We evaluated the diagnostic yield of RT-PCR assays and measured the effect of rapid reporting on patient care.

METHODS

In a controlled clinical trial, nasal wash specimens were obtained from patients <12 years of age with suspected acute respiratory infections. In addition to the standard hospital protocol, RT-PCR assays for 17 pathogens were performed. The RT-PCR results were communicated to the clinicians within 12 to 36 hours in the intervention group and after 4 weeks in the control group.

RESULTS

A total of 583 patients were included (mean age: 8.1 months [range: 0-107.5 months]): 298 in the intervention group and 285 in the control group. Eighty-two percent of nasal wash specimens tested positive for ≥1 pathogen. Respiratory syncytial virus was the most frequently encountered (55%) pathogen. There were no significant differences between the groups with respect to hospital admissions (intervention group: 223 admissions; control group: 211 admissions; P = .825), length of hospital stay (mean ± SD: 3.68 ± 2.68 days [intervention group] and 3.96 ± 2.67 days [control group]; P = .178), or duration of antibiotic use (mean ± SD: 6.52 ± 2.15 days [intervention group] and 6.97 ± 2.86 days [control group]; P = .490), when antibiotic treatment had been initiated.

CONCLUSIONS

RT-PCR testing has a high yield of viral diagnoses, but rapid communication does not lead to decreases in hospital admissions, shorter hospital stays, or less antibiotic use for children with acute respiratory infections.

Sheng-Ma-Ge-Gen-Tang (Shoma-kakkon-to) inhibited cytopathic effect of human respiratory syncytial virus in cell lines of human respiratory tract

ETHNOPHARMACOLOGICAL RELEVANCE

Sheng-Ma-Ge-Gen-Tang (SMGGT; Shoma-kakkon-to) has been used against pediatric viral infection for thousands of year in ancient China. However, it is unknown whether SMGGT is effective against human respiratory syncytial virus (HRSV).

AIM OF THE STUDY

HRSV is a major pediatric viral pathogen of low respiratory tract infection without effective management. This study tested the hypothesis that SMGGT effectively inhibited cytopathy induced by HRSV.

MATERIALS AND METHODS

Effect of the crude extract of SMGGT on HRSV was tested by plaque reduction assay in both human upper (HEp-2) and low (A549) respiratory tract cell lines. Ability of SMGGT to stimulate anti-viral cytokines was evaluated by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Crude extract of SMGGT dose-dependently inhibited HRSV-induced plaque formation. The crude extract was more effective when given before viral infection (p<0.0001). It inhibited viral attachment dose-dependently (p<0.0001) and could increase heparin effect on viral attachment. Furthermore, it was synergistic with very low-dose heparin on viral attachment. In addition, the crude extract time-dependently and dose-dependently (p<0.0001) inhibited HRSV internalization into HEp-2 cells. Epithelial cells secrete IFN-β and TNF-α to counteract viral infection. The crude extract could stimulate epithelial cells to secrete these cytokines beforehand and become resistant to viral infection. It also stimulated IFN-β to defense HRSV after viral inoculation.

CONCLUSIONS

Sheng-Ma-Ge-Gen-Tang could be effective to manage HRSV infection in young children.

Total healthcare costs in the US for preterm infants with respiratory syncytial virus lower respiratory infection in the first year of life requiring medical attention

BACKGROUND

Respiratory syncytial virus (RSV) lower respiratory infection (LRI) is the most common cause of hospitalization among infants <1 year of age. The healthcare costs of preterm infants with RSV LRI were compared with those without RSV LRI in the first year of life.

METHODS

This retrospective cohort study propensity-matched premature infants < or =36 weeks' gestational age (wGA) and/or < or =2499 g birth weight, born May 1, 2001 through April 30, 2006 (five RSV seasons) with RSV LRI to those without RSV LRI in a national United States health plan. The primary outcome was first-year healthcare costs and utilization excluding the birth hospitalization compared between the study cohorts. Subgroup analysis evaluated costs and healthcare resource utilization by GA (< or =32 wGA and 33-36 wGA) and hospitalization status (hospitalized and outpatient).

RESULTS

A total of 2995 infants with RSV LRI were matched to 2995 controls. Infants with RSV LRI had $9115 higher healthcare costs (RSV LRI group: $19 559; control group: $10 444; p < 0.001) in the first year of life. Late preterm infants (33-36 wGA) with an RSV hospitalization incurred $21 977 higher costs (p < 0.001) and those with an outpatient RSV LRI incurred $3898 higher costs (p < 0.001) compared to corresponding controls. Similar results were found among infants < or =32 wGA with higher costs in the RSV LRI group. Rates of all-cause hospitalizations, emergency department visits, and ambulatory visits were significantly higher among infants with RSV LRI compared to controls.

CONCLUSION

Development of RSV LRI among preterm and late preterm infants is associated with significantly higher healthcare costs in the first year of life. These findings must be considered in the context of potential study limitations that may have over- or underestimated costs, such as unconfirmed RSV infection, unintentional omission of fatal cases, and unobserved imbalances between groups.

Cost effectiveness of palivizumab for RSV prevention in high-risk children in the Netherlands

BACKGROUND

Respiratory syncytial virus (RSV) is a common pathogen that is the leading cause of lower respiratory tract infections in young children. High-risk children are at risk of severe infection, which may require hospitalisation. RSV is also associated with a high risk for respiratory morbidity and mortality, which may have long-term clinical and economic consequences.

OBJECTIVE

To assess the cost effectiveness of palivizumab, a humanised monoclonal antibody, used as prevention against severe respiratory syncytial virus (RSV) infection requiring hospitalisation, in the indication of preterm infants and infants with preterm/bronchopulmonary dysplasia and in the second indication of children with congenital heart disease in the Dutch healthcare setting.

METHODS

A decision-tree model was used to estimate the cost effectiveness of palivizumab, used as a preventative treatment against severe respiratory syncytial virus (RSV) infection, in high-risk groups of children in the Netherlands. The analysis was based on a lifetime follow-up period in order to capture the impact of palivizumab on long-term morbidity and mortality resulting from an RSV infection. Data sources included published literature, the palivizumab pivotal trials, official price/tariff lists and national population statistics. The study was conducted from the perspective of society in the Netherlands.

RESULTS

The use of palivizumab results in undiscounted incremental cost-effectiveness ratios of €12,728/QALY and €4,256/QALY in preterm/bronchopulmonary dysplasia and congenital heart disease indications, respectively. Inclusion of indirect costs leads to even more favourable cost-effectiveness outcomes. The study is limited by a number of conservative assumptions. It was assumed that palivizumab only affects the occurrence of RSV hospitalisation and does not influence the severity of the RSV infection. Another assumption was that international clinical trial data and data on utilities could be applied to the Dutch healthcare setting.

CONCLUSION

Palivizumab provides cost-effective prophylaxis against RSV in high-risk infants. The use of palivizumab in these children results in positive short- and long-term health-economic benefits.

Epidemiology

The common cold is the result of an upper respiratory tract infection causing an acute syndrome characterised by a combination of non-specific symptoms, including sore throat, cough, fever, rhinorrhoea, malaise, headache, and myalgia. Respiratory viruses, alone or in combination, are the most common cause. The course f illness can be complicated by bacterial agents, causing pharyngitis or sinusitis, but the are a rare cause of cold and flu-like illnesses (CFLIs). Our understanding of CFLI epidemiology has been enhanced by molecular detection methods, particularly polymerase chain reaction (PCR) testing. PCR has not only improved detection of previously known viruses, but within the last decade has resulted in the detection of many divergent novel respiratory virus species. Human rhinovirus (HRV) infections cause nearly all CFLIs and they can be responsible for asthma and chronic obstructive pulmonary disease exacerbations. HRVs are co-detected with other respiratory viruses in statistically significant patterns, with HRVs occurring in the lowest proportion of co-detections, compared to most other respiratory viruses. Some recently identified rhinoviruses may populate an entirely new putative HRV species; HRV C. Further work is required to confirm a causal role for these newly identified viruses in CFLIs. The burden of illness associated with CFLIs is poorly documented, but where data are available, the impact of CFLIs is considerable. Individual infections, although they do not commonly result in more severe respiratory tract illness, are associated with substantial direct and indirect resource use. The product of frequency and burden for CFLIs is likely to be greater in magnitude than for any other respiratory syndrome, but further work is required to document this. Our understanding of the viral causes of CLFIs, although incomplete, has improved in recent years. Documenting burden is also an important step in progress towards improved control and management of these illnesses.

Excess drug prescriptions during influenza and RSV seasons in the Netherlands: potential implications for extended influenza vaccination

Influenza and respiratory syncytial virus (RSV) infections are responsible for considerable morbidity, mortality and health-care resource use. For the Netherlands, we estimated age and risk-group specific numbers of antibiotics, otologicals and cardiovascular prescriptions per 10,000 person-years during periods with elevated activity of influenza or RSV, and compared these with peri-season rates. Data were taken from the University of Groningen in-house prescription database (www.iadb.nl) and virological surveillance for the period 1998-2006. During influenza and RSV periods excess antibiotic prescriptions were estimated for all age groups. In the age groups 0-1 and 2-4 years, excess antibiotic prescriptions during periods with elevated RSV activity (65% and 59% of peri-seasonal rates) exceeded the surpluses estimated during the influenza-activity periods (24% and 34% of peri-seasonal rates) while for otologicals excess prescriptions were higher for influenza (22% and 27%) than for RSV (14% and 17%). Among persons of 50 years and older, notably those without medical high-risk conditions, excess prescriptions for cardiovascular medications were estimated during the influenza periods at approximately 10% (this was also already seen in persons aged 45-49). Our results may have implications for influenza vaccination policies. In particular, extension of influenza vaccination to groups of non-elderly adults and young children may lower excess prescriptions during these influenza periods for all three types of drug prescriptions investigated.

Nosocomial infection: A risk factor for a complicated course in children with respiratory syncytial virus infection – Results from a prospective multicenter German surveillance study

BACKGROUND

Nosocomially acquired respiratory syncytial virus infections (RSV-NI) may cause serious problems in hospitalized paediatric patients. Hitherto, prospectively collected representative data on RSV-NI from multicenter studies in Germany are limited.

METHODS

The DMS RSV Ped database was designed for the prospective multicenter documentation and analysis of clinically relevant aspects of the management of inpatients with RSV-infection. The study covered six consecutive seasons (1999-2005); the surveillance took place in 14 paediatric hospitals in Germany.

RESULTS

Of the 1568 prospectively documented RSV-infections, 6% (n=90) were NI and 94% (n=1478) were community acquired (CA). A significantly higher proportion in the NI group displayed additional risk factors like prematurity, chronic lung disease, mechanical ventilation (med. history), congenital heart disease, and neuromuscular impairment. Of all NI, 55% occurred in preterms (30.6% of all RSV-infections in preterms with severe chronic lung disease of prematurity were NI). Illness severity as well as the total mortality, but not the attributable mortality was significantly higher in the NI group. In the multivariate analysis, NI was significantly associated with the combined outcome 'complicated course of disease'.

CONCLUSION

This is the first prospective multicenter study from Germany, which confirms the increased risk of a severe clinical course in nosocomially acquired RSV-infection. Of great concern is the high rate of (preventable) NI in preterms, in particular in those with severe chronic lung disease or with mechanical ventilation due to other reasons.

Sensitive commercial NASBA assay for the detection of respiratory syncytial virus in clinical specimen

The aim of the study was to evaluate the usability of three diagnostic procedures for the detection of respiratory syncytial virus in clinical samples. Therefore, the FDA cleared CE marked NOW® RSV ELISA, the NucliSENS® EasyQ RSV A+B NASBA, and a literature based inhouse RT-PCR protocol were compared for their relative sensitivities. Thereby, NASBA turned out to be the most sensitive method with a total number of 80 RSV positive samples out of a cohort of 251 nasopharyngeal washings from patients suffering from clinical symptoms, followed by the inhouse RT-PCR (62/251) and ELISA (52/251). Thus, NASBA may serve as a rapid and highly sensitive alternative for RSV diagnostics.

Respiratory syncytial virus infection in 406 hospitalized premature infants: results from a prospective German multicentre database

Premature birth, chronic lung disease of prematurity (CLD), congenital heart disease and immunodeficiency predispose to a higher morbidity and mortality in respiratory syncytial virus (RSV) infection. This study describes the preterms hospitalised with RSV infection from the prospective German DSM RSV Paed database. The DMS RSV Paed database was designed for the prospective multicentre documentation and analysis of clinically relevant aspects of the management of inpatients with RSV infection. This study covers six consecutive RSV seasons (1999-2005); the surveillance took place in 14 paediatric hospitals in Germany. Of the 1,568 prospectively documented RSV infections, 26% (n=406) were observed in preterms [vs. 1,162 children born at term (74%)] and 3% (n=50) had CLD, of which 49 had received treatment in the last 6 months ('CLDplus'). A significantly higher proportion in the preterm group had congenital heart disease, nosocomial infection, and neuromuscular impairment. There were significantly more children older than 24 months in the preterm group. The attributable mortality was 0.2% (n=2) in children born at term vs. 1.2% (n=5) in the preterm group (p=0.015) [preterm plus CLD 8.0% (n=4 of 50); McIntosh grade 1, 8.6% (n=3 of 35) and McIntosh Grade 4, 15% (n=3 of 20)]. Eight patients were categorized as 'palivizumab failures'. In the multivariate analysis, premature birth, CLD(plus), and nosocomial infection were significantly and independently associated with the combined outcome 'complicated course of disease'. In conclusion, this is the first prospective multicentre study from Germany that confirms the increased risk for severe RSV disease in preterms, in particular in those with CLD treated in the last 6 months before the onset of the infection. From the perspective of our results, the statements of the German Society of Paediatric Infectious Diseases considering the use of passive immunisation (2003) seem reasonable.

A randomized trial of home oxygen therapy from the emergency department for acute bronchiolitis

OBJECTIVE

Hypoxia is a common reason for hospital admission in infants and children with acute bronchiolitis. No study has evaluated discharge from the emergency department (ED) on home oxygen. This study evaluated the feasibility and safety of ED discharge on home oxygen in the treatment of acute bronchiolitis.

METHODS

This was a prospective, randomized trial of infants and children with acute bronchiolitis and hypoxia (room-air saturations of < or =87%) aged 2 to 24 months presenting to an urban, academic, tertiary care children's hospital ED from December 1998 to April 2001. Subjects received inpatient admission or home oxygen after an 8-hour observation period in the ED. We measured the failure to meet discharge criteria during the observation period, return for hospital admission, and incidence of serious complications.

RESULTS

Ninety-two patients were enrolled. Fifty three (58%) were randomly assigned to home and 39 (42%) to inpatient admission. There were no differences between the groups in age, initial room-air saturation, and respiratory distress severity score. Of 53 patients, 37 (70%) randomly assigned to home oxygen completed the observation period and were discharged from the hospital. The remaining 16 patients were excluded from the study (6), resolved their oxygen requirement (5), or failed to meet the discharge criteria and were admitted (5). One discharged patient (2.7%) returned to the hospital and was admitted for a cyanotic spell at home after the 24-hour follow-up appointment. The patient had an uncomplicated hospital course with a length of stay of 45 hours. The remaining 36 patients (97%) were treated successfully as outpatients with home oxygen. Satisfaction with home oxygen was high from the caregiver and the primary care provider.

CONCLUSIONS

Discharge from the ED on home oxygen after a period of observation is an option for patients with acute bronchiolitis. Secondary to the low incidence of complications, the safety of this practice will require a larger study.

Clinical and socio-economic impact of influenza and respiratory syncytial virus infection on healthy children and their households

This prospective study compared the clinical and socio-economic impact of laboratory-confirmed influenza and respiratory syncytial virus (RSV) infection on healthy children and their families. Among 1,520 otherwise healthy children aged< 15 years attending the Emergency Department for acute conditions other than trauma, influenza viruses and RSV were found in 234 (15.4%) and 116 (7.6%; p<0.0001) patients, respectively. The fact that influenza has a similar global clinical impact on the community to that of RSV infection, but represents a greater socio-economic burden, may contribute to broadening the acceptance of influenza vaccination.

Economic impact of community-acquired and nosocomial lower respiratory tract infections in young children in Germany

Data on the economic burden of lower respiratory tract infections (LRTI) in young children are lacking in Germany. The objective of the cost-of-illness study was to estimate the economic impact of community-acquired LRTI and nosocomial LRTI as well as of infections due to respiratory syncytial virus (RSV), parainfluenza viruses (PIV) and influenza viruses (IV). The economic analysis is part of the PRIDE study, a prospective, multi-centre, population-based epidemiological study on the impact of LRTI in children aged 0 to 36 months in Germany. The analysis includes children with community-acquired infections (1329 cases treated as outpatients, 2039 cases treated as inpatients) and nosocomial infections (90 cases). Medical services consumed were generated by chart abstraction and parental expenses data by telephone interviews within four weeks after physician visit or hospitalisation. Costs were evaluated from following perspectives: third party payer, parent and society. Total costs for outpatient treatment are Euro 123 per LRTI case. Stratified by virus type, total costs per case are Euro 163 (RSV), Euro 100 (PIV) and Euro 223 (IV). Total costs per hospitalised LRTI case amount to Euro 2579. Stratified by virus type, total costs per case are Euro 2772 (RSV), Euro 2374 (PIV) and Euro 2597 (IV). Total costs per nosocomial case are Euro 2814. Economic burden due to LRTI is Euro 213 million annually. It is concluded that treatment of LRTI in children up to age three causes a considerable economic burden in Germany. Presented results are the first data describing the economic burden of LRTI in young children assessed by means of the incidence data for Germany. This cost-of-illness study provides basic data for further decision-making, focusing on the economic assessment of preventive strategies for RSV, PIV and IV infections.