A Systematic Review of European Clinical Practice Guidelines for Respiratory Syncytial Virus Prophylaxis.

BACKGROUND: Since the widespread adoption of palivizumab prophylaxis in Europe, there have been a number of clinical practice guidelines (CPGs) published for the prevention of respiratory syncytial virus (RSV) infection in children. The aim of this systematic review was to identify CPGs for the prevention of RSV infection across Europe. METHODS: We performed a systematic literature search and contacted European influenza and respiratory virus networks and public health institutions, to identify national CPGs for the prevention of RSV infection. The Reporting Items for practice Guidelines in Healthcare (RIGHT) Statement checklist was applied to extract data and review the quality of reporting. RESULTS: A total of 20 national CPGs were identified, all published between 2000 and 2018. The greatest discrepancy between guidelines was the recommendations for palivizumab prophylaxis for premature infants, with recommendations varying by gestational age. All guidelines recommended or considered the use of palivizumab in infants with bronchopulmonary dysplasia, 85% (n = 17) in children with congenital heart disease (CHD), and 60% (n = 12) in children with severe combined immunodeficiency. CONCLUSIONS: We recommend that agencies publishing RSV prevention guidelines adopt the RIGHT reporting requirements when updating these guidelines to improve the presentation of the evidence-base for decisions.

Respiratory Syncytial Virus-Associated Hospital Admissions and Bed Days in Children <5 Years of Age in 7 European Countries.

BACKGROUND: Respiratory syncytial virus (RSV) is a leading cause of respiratory tract infections (RTIs) in young children. High-quality country-specific estimates of bed days and length of stay (LOS) show the population burden of RSV-RTI on secondary care services and the burden among patients, and can be used to inform RSV immunization implementation decisions. METHODS: We estimated the hospital burden of RSV-associated RTI (RSV-RTI) in children under 5 years in 7 European countries (Finland, Denmark, Norway, Scotland, England, the Netherlands, and Italy) using routinely collected hospital databases during 2001-2018. We described RSV-RTI admission rates during the first year of life by birth month and assessed their correlation with RSV seasonality in 5 of the countries (except for England and Italy). We estimated average annual numbers and rates of bed days for RSV-RTI and other-pathogen RTI, as well as the hospital LOS. RESULTS: We found that infants born 2 months before the peak month of RSV epidemics more frequently had the highest RSV-RTI hospital admission rate. RSV-RTI hospital episodes accounted for 9.9-21.2 bed days per 1000 children aged <5 years annually, with the median (interquartile range) LOS ranging from 2 days (0.5-4 days) to 4 days (2-6 days) between countries. Between 70% and 89% of these bed days were in infants aged <1 year, representing 40.3 (95% confidence interval [CI], 40.1-40.4) to 91.2 (95% CI, 90.6-91.8) bed days per 1000 infants annually. The number of bed days for RSV-RTI was higher than that for RTIs associated with other pathogens in infants aged <1 year, especially in those <6 months. CONCLUSIONS: RSV disease prevention therapies (monoclonal antibodies and maternal vaccines) for infants could help prevent a substantial number of bed days due to RSV-RTI. "High-risk" birth months should be considered when developing RSV immunization schedules. Variation in LOS between countries might reflect differences in hospital care practices.

Recommendations for respiratory syncytial virus surveillance at the national level.

Respiratory syncytial virus (RSV) is a common cause of acute lower respiratory tract infections and hospitalisations among young children and is globally responsible for many deaths in young children, especially in infants aged <6 months. Furthermore, RSV is a common cause of severe respiratory disease and hospitalisation among older adults. The development of new candidate vaccines and monoclonal antibodies highlights the need for reliable surveillance of RSV. In the European Union (EU), no up-to-date general recommendations on RSV surveillance are currently available. Based on outcomes of a workshop with 29 European experts in the field of RSV virology, epidemiology and public health, we provide recommendations for developing a feasible and sustainable national surveillance strategy for RSV that will enable harmonisation and data comparison at the European level. We discuss three surveillance components: active sentinel community surveillance, active sentinel hospital surveillance and passive laboratory surveillance, using the EU acute respiratory infection and World Health Organization (WHO) extended severe acute respiratory infection case definitions. Furthermore, we recommend the use of quantitative reverse transcriptase PCR-based assays as the standard detection method for RSV and virus genetic characterisation, if possible, to monitor genetic evolution. These guidelines provide a basis for good quality, feasible and affordable surveillance of RSV. Harmonisation of surveillance standards at the European and global level will contribute to the wider availability of national level RSV surveillance data for regional and global analysis, and for estimation of RSV burden and the impact of future immunisation programmes.

Estimating Transmission Parameters for Respiratory Syncytial Virus and Predicting the Impact of Maternal and Pediatric Vaccination.

BACKGROUND: Respiratory syncytial virus (RSV) is a leading cause of respiratory tract illness in young children and a major cause of hospital admissions globally. METHODS: Here we fit age-structured transmission models with immunity propagation to data from the Netherlands (2012-2017). Data included nationwide hospitalizations with confirmed RSV, general practitioner (GP) data on attendance for care from acute respiratory infection, and virological testing of acute respiratory infections at the GP. The transmission models, equipped with key parameter estimates, were used to predict the impact of maternal and pediatric vaccination. RESULTS: Estimates of the basic reproduction number were generally high (R0 > 10 in scenarios with high statistical support), while susceptibility was estimated to be low in nonelderly adults (<10% in persons 20-64 years) and was higher in older adults (≥65 years). Scenario analyses predicted that maternal vaccination reduces the incidence of infection in vulnerable infants (<1 year) and shifts the age of first infection from infants to young children. CONCLUSIONS: Pediatric vaccination is expected to reduce the incidence of infection in infants and young children (0-5 years), slightly increase incidence in 5 to 9-year-old children, and have minor indirect benefits.

Respiratory Syncytial Virus-Associated Hospital Admissions in Children Younger Than 5 Years in 7 European Countries Using Routinely Collected Datasets.

BACKGROUND: Respiratory syncytial virus (RSV) is a leading cause of respiratory tract infection (RTI) in young children. Registries provide opportunities to explore RSV epidemiology and burden. METHODS: We explored routinely collected hospital data on RSV in children aged < 5 years in 7 European countries. We compare RSV-associated admission rates, age, seasonality, and time trends between countries. RESULTS: We found similar age distributions of RSV-associated hospital admissions in each country, with the highest burden in children < 1 years old and peak at age 1 month. Average annual rates of RTI admission were 41.3-112.0 per 1000 children aged < 1 year and 8.6-22.3 per 1000 children aged < 1 year. In children aged < 5 years, 57%-72% of RTI admissions with specified causal pathogen were coded as RSV, with 62%-87% of pathogen-coded admissions in children < 1 year coded as RSV. CONCLUSIONS: Our results demonstrate the benefits and limitations of using linked routinely collected data to explore epidemiology and burden of RSV. Our future work will use these data to generate estimates of RSV burden using time-series modelling methodology, to inform policymaking and regulatory decisions regarding RSV immunization strategy and monitor the impact of future vaccines.

Hospital Admission Trends for Bronchiolitis in Scotland, 2001-2016: A National Retrospective Observational Study.

BACKGROUND: Bronchiolitis is the commonest cause of respiratory related hospital admissions in young children. This study aimed to describe temporal trends in bronchiolitis admissions for children under 2 years of age in Scotland by patient characteristics, socioeconomic deprivation, and duration of admission. METHODS: The national hospital admissions database for Scotland was used to extract data on all bronchiolitis admissions (International Classification of Disease, Tenth Revision, code J21) in children <2 years of age from 2001 to 2016. Deprivation quintiles were classified using the 2011 Scottish Index of Multiple Deprivation. RESULTS: Over the 15-year study period, admission rates for children under 2 years old increased 2.20-fold (95% confidence interval [CI], 1.4-3.6-fold) from 17.2 (15.9-18.5) to 37.7 (37.4-38.1) admissions per 1000 children per year. Admissions peaked in infants aged 1 month, and in those born in the 3 months preceding the peak bronchiolitis month-September, October, and November. Admissions from the most-deprived quintile had the highest overall rate of admission, at 40.5 per 1000 children per year (95% CI, 39.5-41.5) compared with the least-deprived quintile, at 23.0 admissions per 1000 children per year (22.1-23.9). The most-deprived quintile had the greatest increase in admissions over time, whereas the least-deprived quintile had the lowest increase. Zero-day admissions, defined as admission and discharge within the same calendar date, increased 5.3-fold (5.1-5.5) over the study period, with the highest increase in patients in the most-deprived quintile. CONCLUSIONS: This study provides baseline epidemiological data to aid policy makers in the strategic planning of preventative interventions. With the majority of bronchiolitis caused by respiratory syncytial virus (RSV), and several RSV vaccines and monoclonal antibodies currently in clinical trials, understanding national trends in bronchiolitis admissions is an important proxy for determining potential RSV vaccination strategies.

A Systematic Review of Clinical Practice Guidelines for the Diagnosis and Management of Bronchiolitis.

BACKGROUND: Bronchiolitis is the leading cause of hospital admission for respiratory disease among infants aged <1 year. Clinical practice guidelines can benefit patients by reducing the performance of unnecessary tests, hospital admissions, and treatment with lack of a supportive evidence base. This review aimed to identify current clinical practice guidelines worldwide, appraise their methodological quality, and discuss variability across guidelines for the diagnosis and management of bronchiolitis. METHODS: A systematic literature review of electronic databases EMBASE, Global Health, and Medline was performed. Manual searches of the gray literature, national pediatric society websites, and guideline-focused databases were performed, and select international experts were contacted to identify additional guidelines. The Appraisal of Guidelines for Research and Evaluation assessment tool was used by 2 independent reviewers to appraise each guideline. RESULTS: Thirty-two clinical practice guidelines met the selection criteria. Quality assessment revealed significant shortcomings in a number of guidelines, including lack of systematic processes in formulating guidelines, failure to state conflicts of interest, and lack of consultation with families of affected children. There was widespread agreement about a number of aspects, such as avoidance of the use of unnecessary diagnostic tests, risk factors for severe disease, indicators for hospital admission, discharge criteria, and nosocomial infection control. However, there was variability, even within areas of consensus, over specific recommendations, such as variable thresholds for oxygen therapy. Guidelines showed significant variability in recommendations for the pharmacological management of bronchiolitis, with conflicting recommendations over whether use of nebulized epinephrine, hypertonic saline, or bronchodilators should be routinely trialled. CONCLUSIONS: Future guidelines should aim to be compliant with international standards for clinical guidelines to improve their quality and clarity and to promote their adoption into practice. Variable recommendations between guidelines may reflect the evolving evidence base for bronchiolitis management, and platforms should be created to understand this variability and promote evidence-based recommendations.

Global patterns in monthly activity of influenza virus, respiratory syncytial virus, parainfluenza virus, and metapneumovirus: a systematic analysis.

BACKGROUND: Influenza virus, respiratory syncytial virus, parainfluenza virus, and metapneumovirus are the most common viruses associated with acute lower respiratory infections in young children (<5 years) and older people (≥65 years). A global report of the monthly activity of these viruses is needed to inform public health strategies and programmes for their control. METHODS: In this systematic analysis, we compiled data from a systematic literature review of studies published between Jan 1, 2000, and Dec 31, 2017; online datasets; and unpublished research data. Studies were eligible for inclusion if they reported laboratory-confirmed incidence data of human infection of influenza virus, respiratory syncytial virus, parainfluenza virus, or metapneumovirus, or a combination of these, for at least 12 consecutive months (or 52 weeks equivalent); stable testing practice throughout all years reported; virus results among residents in well-defined geographical locations; and aggregated virus results at least on a monthly basis. Data were extracted through a three-stage process, from which we calculated monthly annual average percentage (AAP) as the relative strength of virus activity. We defined duration of epidemics as the minimum number of months to account for 75% of annual positive samples, with each component month defined as an epidemic month. Furthermore, we modelled monthly AAP of influenza virus and respiratory syncytial virus using site-specific temperature and relative humidity for the prediction of local average epidemic months. We also predicted global epidemic months of influenza virus and respiratory syncytial virus on a 5° by 5° grid. The systematic review in this study is registered with PROSPERO, number CRD42018091628. FINDINGS: We initally identified 37 335 eligible studies. Of 21 065 studies remaining after exclusion of duplicates, 1081 full-text articles were assessed for eligibility, of which 185 were identified as eligible. We included 246 sites for influenza virus, 183 sites for respiratory syncytial virus, 83 sites for parainfluenza virus, and 65 sites for metapneumovirus. Influenza virus had clear seasonal epidemics in winter months in most temperate sites but timing of epidemics was more variable and less seasonal with decreasing distance from the equator. Unlike influenza virus, respiratory syncytial virus had clear seasonal epidemics in both temperate and tropical regions, starting in late summer months in the tropics of each hemisphere, reaching most temperate sites in winter months. In most temperate sites, influenza virus epidemics occurred later than respiratory syncytial virus (by 0·3 months [95% CI -0·3 to 0·9]) while no clear temporal order was observed in the tropics. Parainfluenza virus epidemics were found mostly in spring and early summer months in each hemisphere. Metapneumovirus epidemics occurred in late winter and spring in most temperate sites but the timing of epidemics was more diverse in the tropics. Influenza virus epidemics had shorter duration (3·8 months [3·6 to 4·0]) in temperate sites and longer duration (5·2 months [4·9 to 5·5]) in the tropics. Duration of epidemics was similar across all sites for respiratory syncytial virus (4·6 months [4·3 to 4·8]), as it was for metapneumovirus (4·8 months [4·4 to 5·1]). By comparison, parainfluenza virus had longer duration of epidemics (6·3 months [6·0 to 6·7]). Our model had good predictability in the average epidemic months of influenza virus in temperate regions and respiratory syncytial virus in both temperate and tropical regions. Through leave-one-out cross validation, the overall prediction error in the onset of epidemics was within 1 month (influenza virus -0·2 months [-0·6 to 0·1]; respiratory syncytial virus 0·1 months [-0·2 to 0·4]). INTERPRETATION: This study is the first to provide global representations of month-by-month activity of influenza virus, respiratory syncytial virus, parainfluenza virus, and metapneumovirus. Our model is helpful in predicting the local onset month of influenza virus and respiratory syncytial virus epidemics. The seasonality information has important implications for health services planning, the timing of respiratory syncytial virus passive prophylaxis, and the strategy of influenza virus and future respiratory syncytial virus vaccination. FUNDING: European Union Innovative Medicines Initiative Respiratory Syncytial Virus Consortium in Europe (RESCEU).