Respiratory Syncytial Virus Infection: Treatments and Clinical Management

Andrographolide sulfonate downregulation of TLR3-TRIF and amelioration of airway inflammation caused by respiratory syncytial virus infection

Background

Andrographolide sulfonate (Andro-S), a traditional Chinese medicine, is commonly used to treat pediatric respiratory tract infections in China. However, its therapeutic effects in infections caused by respiratory syncytial virus (RSV) have not been reported. We thus aimed to investigate the therapeutic effects of Andro-S using a mouse model of RSV infection-induced airway inflammation.

Methods

Immunocompromised (cyclophosphamide-treated) BALB/c mice were intranasally infected with RSV and treated with intranasal or intraperitoneal Andro-S once daily for five consecutive days, starting on the day of infection. Histopathological changes in the lung were evaluated using hematoxylin and eosin staining. Total inflammatory cell counts and macrophage, lymphocyte, neutrophil, and eosinophil counts in the bronchoalveolar lavage fluid (BALF) were microscopically determined. Interferon-γ (IFN-γ) levels in the BALF were detected using enzyme-linked immunosorbent assay (ELISA). The messenger RNA levels of RSV nucleoprotein (N) and Toll-like receptors (TLRs) 1-9 in lung tissues were determined with quantitative real-time polymerase chain reaction (qRT-PCR). The protein levels of RSV N, RSV fusion protein (F), TLR2, TLR3, and TIR domain-containing adapter-inducing interferon-β (TRIF) were detected via Western blot analysis.

Results

RSV infection caused lung inflammation, manifesting as bronchiolitis, alveolitis, and perivascular inflammation; increased the number of inflammatory cells; and elevated IFN-γ levels in the BALF. Lung inflammation was positively correlated with pulmonary RSV N levels in infected mice. Intranasal Andro-S significantly downregulated RSV N, RSV F, TLR3, and TRIF protein expression in the lung and ameliorated lung inflammation in infected animals. However, intraperitoneal Andro-S showed no effects on lung inflammation caused by RSV infection.

Conclusions

Intranasal Andro-S inhibits RSV replication and ameliorates RSV infection-induced lung inflammation by downregulating TLR3 and TRIF. Therefore, intranasal administration may be a suitable drug delivery method for treating RSV infection.

Epidemiology of Respiratory Syncytial Virus Hospitalizations in Poland: An Analysis from 2015 to 2023 Covering the Entire Polish Population of Children Aged under Five Years

BACKGROUND

Respiratory syncytial virus (RSV) is an important cause of childhood hospitalizations. The aim of the study was to estimate the rates of RSV-related hospitalizations in children aged less than 5 years in Poland.

METHODS

This retrospective observational cohort study was based on data obtained from the National Health Fund in Poland regarding all acute respiratory tract infections and RSV-coded admissions of children (age < 5 years) to public hospitals between July 2015 and June 2023. Patients were stratified based on the following age groups: 0-1 month, 2-3 months, 4-6 months, 7-12 months, 13-24 months, and 25-60 months.

RESULTS

The number of RSV-related hospitalizations increased every season, both before and through the ending phase of the coronavirus disease 2019 (COVID-19) pandemic. The COVID-19 pandemic was associated with a shift in the seasonality pattern of RSV infection. Hospitalization rates per 1000 inhabitants were the highest for children aged 0-12 months, reaching 47.3 in the 2022/23 season. Within this group, the highest hospitalization rate was observed for children aged 2-3 months-94.9 in the 2022/23 season. During the ending phase of the COVID-19 pandemic, the observed increase in admission rates was 2-, 4-, and 5-fold the pre-COVID rate for children aged <12 months, 12-24 months, and 25-60 months, respectively.

CONCLUSIONS

In Poland, RSV infections cause a significant burden in hospitalized children aged less than 5 years. RSV-related hospitalizations were most frequent in children aged less than 1 year. The COVID-19 pandemic was associated with a shift in the seasonality pattern of RSV infections. After the pandemic, more RSV-related hospitalizations were observed in older children (aged 13 months and older) vs. the pre-pandemic phase.

Wastewater-based surveillance as a tool for public health action: SARS-CoV-2 and beyond

Wastewater-based surveillance (WBS) has undergone dramatic advancement in the context of the coronavirus disease 2019 (COVID-19) pandemic. The power and potential of this platform technology were rapidly realized when it became evident that not only did WBS-measured SARS-CoV-2 RNA correlate strongly with COVID-19 clinical disease within monitored populations but also, in fact, it functioned as a leading indicator. Teams from across the globe rapidly innovated novel approaches by which wastewater could be collected from diverse sewersheds ranging from wastewater treatment plants (enabling community-level surveillance) to more granular locations including individual neighborhoods and high-risk buildings such as long-term care facilities (LTCF). Efficient processes enabled SARS-CoV-2 RNA extraction and concentration from the highly dilute wastewater matrix. Molecular and genomic tools to identify, quantify, and characterize SARS-CoV-2 and its various variants were adapted from clinical programs and applied to these mixed environmental systems. Novel data-sharing tools allowed this information to be mobilized and made immediately available to public health and government decision-makers and even the public, enabling evidence-informed decision-making based on local disease dynamics. WBS has since been recognized as a tool of transformative potential, providing near-real-time cost-effective, objective, comprehensive, and inclusive data on the changing prevalence of measured analytes across space and time in populations. However, as a consequence of rapid innovation from hundreds of teams simultaneously, tremendous heterogeneity currently exists in the SARS-CoV-2 WBS literature. This manuscript provides a state-of-the-art review of WBS as established with SARS-CoV-2 and details the current work underway expanding its scope to other infectious disease targets.

Resurgence of human respiratory syncytial virus during COVID-19 pandemic in Southern Brazil

Respiratory Syncytial Virus (RSV) is an important cause of respiratory infection in humans. Severe cases are common in children ≤2 years old, immunocompromised individuals, and the elderly. In 2020, RSV infection reduced in Rio Grande do Sul (RS), southern Brazil; however, in 2021 resurgence of RSV was observed. This study analyzed epidemiological and genetic features of RSV infection cases reported in 2021 in RS. Nasopharyngeal samples collected from individuals with respiratory infection negative for SARS-CoV-2, Influenza A and B viruses were assessed for the presence of RSV by real time RT-qPCR. RSV-A and RSV-B genomic sequencing and phylogenetic reconstructions were performed for genotyping and clade characterization. Among 21,035 respiratory samples analyzed, 2,947 were positive for RSV, 947 of which were hospitalized patients. Positive cases were detected year-round, with the highest number in June-July (winter). Children <1 year comprised 56.28% (n = 533) of the hospitalized patients infected with RSV, whereas 14.46% (n = 137) were individuals >60 years. Of a total of 361 deaths, 14.68% (n = 53) were RSV positive, mostly patients >60 years old (73.58%, n = 39). Chronic kidney disease, cardiopathy, Down syndrome and neurological diseases were associated with RSV infection. RSV-A was identified in 58.5% (n = 117/200) of the patients, and RSV-B in 41.5% (n = 83/200). Of 95 RSV genomes recovered from SARI cases, 66 were RSV-A GA.2.3.5 genotype, while 29 were RSV-B GB.5.0.5a genotype. This study provides epidemiological and molecular data on RSV cases in RS during the COVID-19 pandemic and highlights that investigation of different respiratory viruses is essential for decision-making and disease prevention and control measures.

Costs and healthcare utilisation due to respiratory syncytial virus disease in paediatric patients in Italy: a systematic review

OBJECTIVES

Respiratory syncytial virus (RSV) is a frequent cause of acute lower respiratory infection in children, imposing a substantial economic burden on healthcare systems. This systematic review aimed to assess the economic burden and healthcare utilisation of RSV in children aged 0-59 months in Italy.

STUDY DESIGN

Systematic review.

METHODS

A systematic search of PubMed, Embase, Scopus, and the International HTA Database, including studies published in English or Italian, was conducted between January 2000 and July 2022. Inclusion criteria required studies to be conducted in Italy and provide data on the economic costs and healthcare resource utilisation related to RSV infections.

RESULTS

Out of 20,845 records screened, 18 articles met the inclusion criteria. Only one study provided comprehensive data on RSV disease costs, including hospitalisation, diagnostic tests, and medical procedures for infants with RSV-bronchiolitis. The mean cost per inpatient was higher for RSV-positive children (€5753.43 ± €2041.62) than that for RSV-negative children. Additionally, five studies reported a median length of hospital stay of 5 days for RSV-infected children, and four studies indicated a higher frequency of intensive care unit admissions for RSV-infected children than for those with other viral infections.

CONCLUSIONS

This is the first systematic review to examine the economic burden and healthcare utilisation of RSV in children aged 0-59 months in Italy. While limited data were available, the findings underscore the urgency to conduct further research and gather additional evidence on the costs and healthcare resource utilisation associated with RSV infections. Such efforts are essential for informing the development of effective prevention strategies for paediatric RSV infections in Italy.

The Estimate of Parental Quality of Life Loss Due to Respiratory Syncytial Virus (RSV) Hospitalization

BACKGROUND

Respiratory syncytial virus (RSV) is one of the leading causes of pediatric hospitalizations, mainly in children under 2 years of age. Hospitalization affects the caregivers' quality of life (QoL). We assessed the caregivers' QoL during RSV-confirmed hospitalizations of children under 2 years old, identified the most affected QoL dimensions and calculated utilities focusing on the assessment methods and potential confounders.

METHODS

The caregivers filled out the EQ-5D questionnaire, consisting of a descriptive system (assessing 5 QoL dimensions) and a visual analog scale (EQ VAS). Utility, utility loss and quality-adjusted life years (QALY) loss were calculated, and a concordance between the two systems was assessed.

RESULTS

A disturbance in any of the five assessed dimensions was reported by 42% (55 out of 132) of the caregivers, mostly anxiety/depression (37%) and pain/discomfort (17%). The utilities varied between 0.17 and 1 in the descriptive system and 0.33-1 (median 0.86) in the EQ VAS, with a utility loss of 0.14 (IQR: 0.1-0.2). The calculated QALY loss reached a median of 2.45 × 10-3 (IQR: 1.37 × 10-3-4.56 × 10-3) and was not influenced by the patient's age or the final clinical diagnosis (QALY loss for bronchiolitis: 2.74 × 10-3, pneumonia: 1.84 × 10-3, bronchitis: 1.78 × 10-3, differences statistically insignificant). Only a moderate concordance between the descriptive system and the EQ VAS was seen (Spearman's rank correlation coefficient = 0.437, p < 0.05), with the latter revealing a higher degree of QoL disturbances.

CONCLUSIONS

RSV hospitalization influences parental QoL significantly, and anxiety/depression is the most commonly reported issue. Utility impairment scores depend on the assessment method but not on the patient's age or final diagnosis. Thus, the impact of RSV on caregivers' QoL cannot be underestimated.

Vitamin D3 protects against respiratory syncytial virus-induced barrier dysfunction in airway epithelial cells via PKA signaling pathway

Respiratory syncytial virus (RSV) is the leading cause of acute lower respiratory tract infection in infants and young children globally and is responsible for hospitalization and mortality in the elderly population. Virus-induced airway epithelial barrier damage is a critical step during RSV infection, and emerging studies suggest that RSV disrupts the tight junctions (TJs) and adherens junctions (AJs) between epithelial cells, increasing the permeability of the airway epithelial barrier. The lack of commercially available vaccines and effective antiviral drugs for RSV emphasizes the need for new management strategies. Vitamin D3 is a promising intervention for viral infection due to its critical role in modulating innate immune responses. However, there is limited evidence on the effect of vitamin D3 on RSV pathogenies. Here, we investigated the impact of vitamin D3 on RSV-induced epithelial barrier dysfunction and the underlying mechanisms. We found that pre-incubation with 1,25(OH)2D3, the active form of vitamin D3, alleviated RSV-induced epithelial barrier disruption in a dose-dependent manner without affecting viability in 16HBE cells. 1,25(OH)2D3 induced minor changes in the protein expression level of TJ/AJ proteins in RSV-infected cells. We observed increased CREB phosphorylation at Ser133 during 1,25(OH)2D3 exposure, indicating that vitamin D3 triggered protein kinase A (PKA) activity in 16HBE. PKA inhibitors modified the restoration of barrier function by 1,25(OH)2D3 in RSV-infected cells, implying that PKA signaling is responsible for the protective effects of vitamin D3 against RSV-induced barrier dysfunction in airway epithelial cells. Our findings suggest vitamin D3 as a prophylactic intervention to protect the respiratory epithelium during RSV infections.

The Impact of RSV Hospitalization on Children's Quality of Life

BACKGROUND

Respiratory syncytial virus (RSV) is one of the most frequent etiological factors of lower respiratory tract infections in children, potentially affecting patients' quality of life (QoL). We aimed to asses QoL in children under 2 years of age hospitalized due to laboratory-confirmed RSV infection.

METHODS

A QoL was assessed by parents/tutors with the use of the 100-point visual analog scale and compared against a disease-free period. We evaluated the median utility, QoL loss (reported in days), and quality-adjusted life years (QALY) loss in relation to RSV hospitalization.

RESULTS

We included 132 patients aged from 17 days to 24 months (median 3.8 months). The mean utility during the hospitalization varied between 0.418 and 0.952, with a median of 0.679 (95%CI: 0.6-0.757) and median loss of 0.321 [0.243-0.4], which further translated into a loss of 2.2 days (95%CI: 1.6-3.1). The QALY loss varied between 0.526 × 10-3 and 24.658 × 10-3, with a median of 6.03 × 10-3 (95%CI: 4.38-8.48 × 10-3). Based upon the final diagnoses, the highest QALY loss was 6.99 × 10-3 (95%CI: 5.29-13.7 × 10-3) for pneumonia, followed by bronchiolitis-5.96 × 10-3 (4.25-8.41 × 10-3) and bronchitis-4.92 × 10-3 (2.93-6.03 × 10-3); significant differences were observed only between bronchitis and pneumonia (p = 0.0171); the QALY loss was not age-dependent. Although an increasing tendency in the utility score was observed, a strong cumulative effect related to the length of stay was noted until day 13.

CONCLUSIONS

RSV contributes significantly to the utility deterioration and QALY loss in the case of RSV hospitalization, and the patient-reported data should be used in pharmacoeconomic assessments of the impact of RSV.