Severe Respiratory Syncytial Virus Infection in Hospitalized Children Less Than 3 Years of Age in a Temperate and Tropical Climate

Clinical outcomes and severity of laboratory-confirmed RSV compared with influenza, parainfluenza and human metapneumovirus in Australian children attending secondary care

INTRODUCTION

Acute lower respiratory infections (ALRIs) are a major contributor to the global infectious disease burden and a common cause of hospitalisation for children under 2 years. We compared clinical severity in children hospitalised with respiratory syncytial virus (RSV), parainfluenza virus (PIV), human metapneumovirus (hMPV) and influenza virus (IFV).

METHODS

We used a probabilistically linked population cohort born in Western Australia between 2010 and 2020 and hospitalised before the age of 2 years. Outcomes compared included length of hospital stay (LOS), admission to intensive care unit (ICU), need for respiratory support (RS), complex hospital course (RS, death, ICU admission or LOS >75th percentile), 7-day and 30-day mortality, hospital-in-the-home care, 30-day all-cause and ALRI-specific readmissions and emergency department presentations 14 days prior to hospitalisation. Logistic regression was used for binary outcomes, and negative binomial regression was used for discrete count variables. Incidence rates, time to RS and time to readmissions were calculated using survival analysis techniques.

RESULTS

The final cohort included 210 997 hospitalised children under 24 months of age for a total of 315 769 admissions. Infants hospitalised before 6 months had the highest rates for all virus-specific hospitalisations, particularly RSV hospitalisations (50.4 per 1000 child-years (95% CI 48.7 to 52.1)). Infants <6 months had higher odds of an ICU admission (adjusted OR (aOR) 2.39, 95% CI 1.36 to 4.19) and RS (aOR 4.68, 95% CI 2.95 to 7.44) and a complex hospital course (aOR 2.69, 95% CI 2.13 to 3.42) with RSV and four times higher hazards of requiring RS earlier (adjusted HR (aHR) 4.06, 95% CI 2.59 to 6.36). An ALRI-coded 30-day readmission was recorded in 10%-24% of virus-specific hospitalisations.

DISCUSSION

Young infants have a more severe and complex hospital course with RSV hospitalisation compared with hospitalisation with other respiratory viruses and should be prioritised for prevention measures such as the single-dose monoclonal antibody, nirsevimab.

Risk factors for severe respiratory syncytial virus-associated respiratory tract infection in a high HIV prevalence setting, South Africa, 2012 - 2018

BACKGROUND

Identifying risk factors for respiratory syncytial virus (RSV)-associated severe acute respiratory illness (SARI) will assist with targeting vaccine interventions.

METHODS

Using surveillance data from South Africa (2012-2018), we compared the characteristics of individuals with RSV-associated influenza-like illness (ILI) (reference group) to those with RSV-associated SARI to describe factors associated with SARI using a multivariable analysis.

RESULTS

RSV was detected in 6% (483/7792) of ILI cases and 15% (844/5672) of SARI cases. Factors associated with SARI in children included age < 2 months, compared to age 2-4 years (adjusted odds ratio (aOR) 54.4; 95% confidence interval (CI) 23.5-125.8), malnutrition (aOR 1.9; 95% CI 1.2-3.2), prematurity (aOR 2.4; 95% CI 1.3-4.6) and living with HIV (LWH) (aOR 22.5; 95% CI 2.9-174.3). In individuals ≥ 5 years, factors associated with SARI included age ≥ 65 years compared to age 5-24 years (aOR 10.7; 95% CI 1.1-107.5), symptom duration ≥ 5 days (aOR 2.7; 95% CI 1.1-6.3), underlying illness (aOR 2.7; 95% CI 1.5-26.1) and LWH (aOR 16.8, 95% CI: 4.8-58.2).

CONCLUSION

Individuals at the extremes of age and those with identified risk factors might benefit most from RSV prevention interventions.

CLINICAL TRIAL NUMBER

Not applicable, this is not a clinical trial.

Respiratory Viral Testing Rate Patterns in Young Children Attending Tertiary Care Across Western Australia: A Population-Based Birth Cohort Study

BACKGROUND

An understanding of viral testing rates is crucial to accurately estimate the pathogen-specific hospitalisation burden. We aimed to estimate the patterns of testing for respiratory syncytial virus (RSV), influenza virus, parainfluenza virus (PIV) and human metapneumovirus (hMPV) by geographical location, age and time in children <5 years old in Western Australia.

METHODS

We conducted a population-based cohort study of children born between 1 January 2010 and 31 December 2021, utilising linked administrative data incorporating birth and death records, hospitalisations and respiratory viral surveillance testing records from state-wide public pathology data. We examined within-hospital testing rates using survival analysis techniques and identified independent predictors of testing using binary logistic regression.

RESULTS

Our dataset included 46,553 laboratory tests for RSV, influenza, PIV, or hMPV from 355,021 children (52.5% male). Testing rates declined in the metropolitan region over the study period (RSV testing in infants: from 242.11/1000 child-years in 2012 to 155.47/1000 child-years in 2018) and increased thereafter. Conversely, rates increased in non-metropolitan areas (e.g., RSV in Goldfields: from 364.92 in 2012 to 504.37/1000 child-years in 2021). The strongest predictors of testing were age <12 months (adjusted odds ratio [aOR] = 2.25, 95% CI 2.20-2.31), preterm birth (<32 weeks: aOR = 2.90, 95% CI 2.76-3.05) and remote residence (aOR = 0.77, 95% CI 0.73-0.81).

CONCLUSION

These current testing rates highlight the potential underestimation of respiratory virus hospitalisations by routine surveillance and the need for estimation of the true burden of respiratory virus admissions.

[Expert recommendations for the prevention of common respiratory viral infections in neonates]

Neonates, particularly preterm infants, are a susceptible population to respiratory viral infections. Currently, aside from influenza, there are no antiviral medications specifically approved for the treatment of respiratory viral infections in neonates; therefore, prevention of these viral infections is particularly crucial for neonates. The Neonatal HealthCare Committee of Chinese Maternal and Child Health Association, based on domestic and international clinical evidence and combined with clinical practice experience, and after thorough discussion by relevant experts, has developed eight expert recommendations. These include preventive strategies against influenza virus, respiratory syncytial virus, and severe acute respiratory syndrome coronavirus 2 infections, intended for reference in clinical practice.

Burden of respiratory syncytial virus disease across the lifespan in Australia and New Zealand: a scoping review

OBJECTIVES

Respiratory syncytial virus (RSV) is the leading cause of acute lower respiratory tract infection in young children worldwide. RSV is increasingly associated with severe respiratory disease in people aged >65 years. The heterogeneous landscape of RSV in Australia and New Zealand makes generalisation of results from global studies to local contexts difficult. Given the changing landscape of RSV, we aimed to examine the existing literature on the burden of RSV disease and identify evidence gaps in Australia and New Zealand.

STUDY DESIGN

Scoping review.

METHODS

We designed a scoping review protocol and searched the Web of Science and Scopus databases for eligible peer-reviewed publications. Data from eligible studies were charted and summarised in tabular and narrative form.

RESULTS

Of the 153 eligible publications identified, 123 investigated RSV disease in a hospital setting and six in primary care. Only six studies reported the economic burden of disease, all of which estimated direct healthcare costs associated with treatment and/or hospitalisation; no studies quantified the indirect costs or costs to families.

CONCLUSIONS

In this scoping review, we describe the effect of RSV disease in several high-risk populations, including children and adults. An improved understanding of the RSV burden of disease, both in primary care settings and economically, within the local context will assist with the implementation of preventative strategies, including vaccination programmes. Future studies to determine the true burden of RSV-associated morbidity, mortality and economic burden across the entire patient journey and among different healthcare settings will help prioritise emerging RSV therapeutics.

Respiratory syncytial virus disease morbidity in Australian infants aged 0 to 6 months: a systematic review with narrative synthesis

BACKGROUND

A significant proportion of the global respiratory syncytial virus (RSV) associated morbidity is accounted for by infants aged 0 to 6 months, who are particularly vulnerable to severe disease. In 2015, 44% of global hospitalisations in infants in this age group were secondary to RSV. The objective of this systematic review is to appraise and synthesise the local evidence of RSV infection morbidity among Australian infants aged 0 to 6 months and to assess the implications for future immunisation strategies.

METHODS

Electronic databases (Medline, Embase, Pubmed and Global Health) were searched for full-text articles published between 2000 and 2023 in English language. Studies that examined markers of RSV disease morbidity in infants aged 0 to 6 months in Australia who had laboratory confirmed RSV infection were eligible for inclusion. The outcomes of interest were incidence, prevalence, testing rate, positivity rate, mortality, emergency department visits, community health visits, hospitalisation, intensive care unit admission, supplementary oxygen use, mechanical ventilation, risk factors for disease severity and monoclonal antibody use.

RESULTS

The database search identified 469 studies. After removal of duplicates and full-text review, 17 articles were eligible for inclusion. This review was reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and Synthesis without meta-analysis guidelines.

CONCLUSIONS

Qualitative analysis of the included studies showed that Australian infants aged 0 to 6 months have higher rates of RSV testing, positivity and incidence; and more likely to develop severe disease that requires hospitalisation, intensive care unit admission or respiratory support, compared to children and adults of all ages. Aboriginal and Torres Strait Islander infants aged 0 to 6 months demonstrated higher rates of RSV infection and hospitalisation, compared to non-Indigenous infants. Age-related trends persisted in geographic areas with varying seasonal transmission of RSV, and during the SARS-CoV-2 pandemic. Passive immunisation strategies targeting infants in their first 6 months of life, either via vaccination of pregnant women or administration of long-acting monoclonal antibody during infancy, could effectively reduce RSV disease burden in Australia.

Factors associated with severe respiratory syncytial virus disease in hospitalised children: a retrospective analysis

BACKGROUND

Early recognition of children at risk of severe respiratory syncytial virus (RSV) lower respiratory tract infection is important as it informs management decisions. We aimed to evaluate factors associated with severe disease among young children hospitalised with RSV infection.

METHODS

We conducted a retrospective cohort study of all children <2 years of age hospitalised for RSV lower respiratory tract infection at a single tertiary paediatric hospital over three RSV seasons (January 2017-December 2019). We classified children as having 'moderate' or 'severe' disease based on the level of respiratory intervention and used univariable and multivariable regression models to determine factors associated with severe disease.

RESULTS

Of 970 hospitalised children, 386 (40%) were classified as having 'severe' and 584 (60%) as having 'moderate' RSV disease. On multivariable analyses, age <2 months (OR: 2.3, 95% CI 1.6 to 3.3, p<0.0001), prematurity (OR: 1.6, 95% CI 1.1 to 2.4, p=0.02) and RSV-parainfluenza virus type 3 (PIV3) codetection (OR: 2.6, 95% CI 1.05 to 6.5, p=0.04) were independently associated with severe disease.

CONCLUSION

Younger age, prematurity and PIV3 codetection were associated with severe RSV disease in children <2 years of age hospitalised with RSV infection. The association between PIV3 and severe RSV disease is a novel finding and warrants further investigation.

Risk factors and incidence of invasive bacterial infection in severe bronchiolitis: the RICOIB prospective study

Background

Bacterial infection (BI), both community-acquired (CA-BI) and hospital-acquired (HAI), might present as a severe complication in patients with bronchiolitis. This study aimed to describe BI in children with severe bronchiolitis, and to define risk factors for BI.

Methods

This was a prospective, descriptive study that included infants admitted to the pediatric intensive care unit (PICU) due to bronchiolitis between 2011 and 2017. The BROSJOD score was calculated to rate the severity of bronchiolitis.

Results

Inclusion of 675 patients, with a median age of 47 days (IQR 25–99). 175 (25.9%) patients developed BI, considered HAI in 36 (20.6%). Patients with BI had higher BROSJOD score, PRISM III, and required invasive mechanical ventilation and inotropic support more frequently (p < 0.001). BI was independently associated with BROSJOD higher than 12 (OR 2.092, 95%CI 1.168–3.748) CA-BI was associated to BROSJOD > 12 (OR 2.435, 95%CI 1.379–4.297) and bacterial co-infection (OR 2.294 95%CI 1.051–5.008). Concerning HAI, an independent association was shown with mechanical ventilation longer than 7 days (OR 5.139 95%CI 1.802–14.652). Infants with BI had longer PICU and hospital stay (p < 0.001), Mortality was higher in patients with HAI.

Conclusions

A quarter of infants with severe bronchiolitis developed BI. A BROSJOD > 12 may alert the presence of CA-BI, especially pneumonia. Patients with BI have higher morbidity and mortality.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-022-03206-4.

Disparities in Outcomes During Lower Respiratory Tract Infection in American Indian Children: A 9-Year Retrospective Analysis in a Rural Population in South Dakota

BACKGROUND

American Indian (AI) children are at increased risk for severe disease during lower respiratory tract infection (LRTI). The reasons for this increased severity are poorly understood. The objective of this study was to define the clinical presentations of LRTI and highlight the differences between AI and non-AI previously healthy patients under the age of 24 months.

METHODS

We performed a retrospective chart review between October 2010 and December 2019. We reviewed 1245 patient charts and 691 children met inclusion criteria for this study. Data records included demographics, clinical, laboratory data, and illness outcomes.

RESULTS

Of 691 patients, 120 were AI and 571 were non-AI. There was a significant difference in breast-feeding history (10% of AI vs. 28% of non-AI, P < 0.0001) and in secondhand smoke exposure (37% of AI vs. 21% of non-AI, P < 0.0001). AI children had increased length of hospitalization compared with non-AI children (median of 3 vs. 2 days, P < 0.001). In addition, AI children had higher rates of pediatric intensive unit admission (30%, n = 37) compared with non-AI children (11%; n = 67, P < 0.01). AI children also had higher rates (62.5%, n = 75) and duration of oxygen supplementation (median 3 days) than non-AI children (48%, n = 274, P = 0.004; median 2 days, P = 0.0002). On a multivariate analysis, AI race was an independent predictor of severe disease during LRTI.

CONCLUSIONS

AI children have increased disease severity during LRTI with longer duration of hospitalization and oxygen supplementation, a higher rate of oxygen requirement and Powered by Editorial Manager and ProduXion Manager from Aries Systems Corporation pediatric intensive care unit admissions, and a greater need for mechanical ventilation. These results emphasize the need for improvement in health policies and access to health care in this vulnerable population.