More on Viral Bronchiolitis in Children

Antibiotic Utilization in Hospitalized Children with Bronchiolitis: A Prospective Study Investigating Clinical and Epidemiological Characteristics at a Secondary Hospital in Madrid (2004-2022)

Bronchiolitis is a viral respiratory infection, with respiratory syncytial virus (RSV) being the most frequent agent, requiring hospitalization in 1% of affected children. However, there continues to be a noteworthy incidence of antibiotic prescription in this setting, further exacerbating the global issue of antibiotic resistance. This study, conducted at Severo Ochoa Hospital in Madrid, Spain, focused on antibiotic usage in children under 2 years of age who were hospitalized for bronchiolitis between 2004 and 2022. In that time, 5438 children were admitted with acute respiratory infection, and 1715 infants (31.5%) with acute bronchiolitis were included. In total, 1470 (87%) had a positive viral identification (66% RSV, 32% HRV). Initially, antibiotics were prescribed to 13.4% of infants, but this percentage decreased to 7% during the COVID-19 pandemic thanks to adherence to guidelines and the implementation of rapid and precise viral diagnostic methods in the hospital. HBoV- and HAdV-infected children and those with viral coinfections were more likely to receive antibiotics in the univariate analysis. A multivariate logistic regression analysis revealed a statistically independent association between antibiotic prescription and fever > 38 °C (p < 0.001), abnormal chest-X ray (p < 0.001), ICU admission (p = 0.015), and serum CRP (p < 0.001). In conclusion, following guidelines and the availability of rapid and reliable viral diagnostic methods dramatically reduces the unnecessary use of antibiotics in infants with severe bronchiolitis.

Time trend and seasonality in medically attended respiratory syncytial virus (RSV) infections in US children aged 0-5 years, January 2010-January 2023

OBJECTIVE

The long-term time trend and seasonality variations of first-time medically attended respiratory syncytial virus (RSV) infections among young children are unknown. We aim to examine the time trend of medically attended first-time RSV infections among young children in the USA from January 2010 through January 2023.

DESIGN

This is a population-based cohort study using electronic health records (EHRs). Monthly incidence rate of medically attended first-time RSV infection (cases per 10 000 000 person-days). A time-series regression model was used to model and predict time trends and seasonality.

SETTING

Multicenter and nationwide TriNetX Network in the USA.

PARTICIPANTS

The study population comprised children aged 0-5 years who had medical visits during the period of January 2010 to January 2023.

RESULTS

The data included 29 013 937 medical visits for children aged 0-5 years (46.5% girls and 53.5% boys) from January 2010 through January 2023. From 2010 through 2019, the monthly incidence rate of first-time medically attended RSV infection in children aged 0-5 years followed a consistent seasonal pattern. Seasonal patterns of medically attended RSV infections were significantly disrupted during the COVID-19 pandemic. In 2020, the seasonal variation disappeared with a peak incidence rate of 20 cases per 1 000 000 person-days, a decrease of 97.4% from the expected peak rate (rate ratio or RR: 0.026, 95% CI 0.017 to 0.040). In 2021, the seasonality returned but started 4 months earlier, lasted for 9 months, and peaked in August at a rate of 753 cases per 1 000 000 person-days, a decrease of 9.6% from the expected peak rate (RR: 0.90, 95% CI 0.82 to 0.99). In 2022, the seasonal pattern is similar to prepandemic years but reached a historically high rate of 2182 cases per 10 000 000 person-days in November, an increase of 143% from the expected peak rate (RR: 2.43, 95% CI 2.25 to 2.63). The time trend and seasonality of the EHR-based medically attended RSV infections are consistent with those of RSV-associated hospitalisations from the Centers for Disease Control and Prevention (CDC) survey-based surveillance system.

CONCLUSION

The findings show the disrupted seasonality during the COVID-19 pandemic and a historically high surge of paediatric RSV cases that required medical attention in 2022. Our study demonstrates the potential of EHRs as a cost-effective alternative for real-time pathogen and syndromic surveillance of unexpected disease patterns including RSV infection.

SARS-CoV-2-related bronchiolitis: a multicentre international study

BACKGROUND

Bronchiolitis is the main acute lower respiratory tract infection in infants. Data regarding SARS-CoV-2-related bronchiolitis are limited.

OBJECTIVE

To describe the main clinical characteristics of infants with SARS-CoV-2-related bronchiolitis in comparison with infants with bronchiolitis associated with other viruses.

SETTING, PATIENTS, INTERVENTIONS

A multicentre retrospective study was conducted in 22 paediatric emergency departments (PED) in Europe and Israel. Infants diagnosed with bronchiolitis, who had a test for SARS-CoV-2 and were kept in clinical observation in the PED or admitted to hospital from 1 May 2021 to 28 February 2022 were considered eligible for participation. Demographic and clinical data, diagnostic tests, treatments and outcomes were collected.

MAIN OUTCOME MEASURES

The main outcome was the need for respiratory support in infants testing positive for SARS-CoV-2 compared with infants testing negative.

RESULTS

2004 infants with bronchiolitis were enrolled. Of these, 95 (4.7%) tested positive for SARS-CoV-2. Median age, gender, weight, history of prematurity and presence of comorbidities did not differ between the SARS-CoV-2-positive and SARS-CoV-2-negative infants. Human metapneumovirus and respiratory syncytial virus were the viruses most frequently detected in the group of infants negative for SARS-CoV-2.Infants testing positive for SARS-CoV-2 received oxygen supplementation less frequently compared with SARS-CoV-2-negative patients, 37 (39%) vs 1076 (56.4%), p=0.001, OR 0.49 (95% CI 0.32 to 0.75). They received less ventilatory support: 12 (12.6%) high flow nasal cannulae vs 468 (24.5%), p=0.01; 1 (1.0%) continuous positive airway pressure vs 125 (6.6%), p=0.03, OR 0.48 (95% CI 0.27 to 0.85).

CONCLUSIONS

SARS-CoV-2 rarely causes bronchiolitis in infants. SARS-CoV-2-related bronchiolitis mostly has a mild clinical course.

Bronchiolitis before and after the SARS-CoV-2 pandemic: Twelve years of experience in a Spanish paediatric hospital

INTRODUCTION

Acute bronchiolitis is the main cause of hospitalization in children under 2 years of age, with a regular seasonality, mostly due to the respiratory syncytial virus.

OBJECTIVES

To describe the epidemiology of bronchiolitis hospitalizations in our center in the last 12 years, and analyze the changes in clinical characteristics, microbiology, and adverse outcomes during the SARS-CoV-2 pandemic.

METHODS

Observational study including patients admitted for bronchiolitis between April 2010 and December 2021 in a Spanish tertiary paediatric hospital. Relevant demographic, clinical, microbiological, and adverse outcome variables were collected in an anonymized database. The pandemic period (April 2020 to December 2021) was compared to 2010-2015 seasons using appropriate statistical tests.

RESULTS

There were 2138 bronchiolitis admissions, with a mean of 195.6 per year between 2010 and 2019 and a 2-4-month peak between November and March. In the expected season of 2020, there was a 94.4% reduction of bronchiolitis hospitalizations, with only 11 cases admitted in the first year of the pandemic. Bronchiolitis cases increased from the summer of 2021 during a 6-month long peak, reaching a total of 171 cases. Length of stay was significantly shorter during the pandemic, but no differences were found in clinical and microbiological characteristics or other adverse outcomes.

CONCLUSIONS

The SARS-CoV-2 pandemic has modified the seasonality of bronchiolitis hospitalizations, with a dramatic decrease in cases during the expected season of 2020-2021, and an extemporaneous summer-autumn peak in 2021 with longer duration but similar patient characteristics and risk factors.

Asthma risk after a pediatric intensive care unit admission for respiratory syncytial virus bronchiolitis

BACKGROUND

Admission to a pediatric intensive care unit (PICU) has been associated with respiratory consequences in children with asthma and carries major implications for management control. Whereas respiratory syncytial virus (RSV) bronchiolitis has been associated with increasing intensity of wheezing, the relationship between RSV-bronchiolitis PICU admission and future asthma is unclear. This retrospective case-control study evaluated whether hospitalization in the PICU due to RSV bronchiolitis is more likely to be associated with future asthma in early life compared with hospitalization in a general pediatric ward.

METHODS

Children hospitalized due to RSV bronchiolitis between 2007 and 2019 in the PICU (study group) were compared to those hospitalized in a general pediatric ward (controls). Asthma prevalence was assessed by a follow-up questionnaire based on The International Study of Asthma and Allergies in Childhood questionnaire.

RESULTS

Sixty-three PICU patients and 66 controls were included. The PICU patients presented with more severe disease during RSV hospitalization. At follow-up, significantly more PICU patients aged 3-6 years had physician-diagnosed asthma, respiratory symptoms during the previous 12 months, and underwent respiratory treatment since hospital discharge compared to controls (14 [60.9%] vs. 4 [18.2%] patients; 15 [65.2%] vs. 6 [27.3%]; and 16 [69.6%] vs. 8 [36.4%]; respectively). These differences were no longer observed after 6 years of age.

CONCLUSIONS

Children admitted to the PICU for RSV bronchiolitis are at higher risk for asthma in subsequent pre-school years and will require close respiratory follow-up than those admitted to general pediatric wards. Admission venue should be queried when asthma is suspected.

Dietary Cholesterol Exacerbates Statin-Induced Hepatic Toxicity in Syrian Golden Hamsters and in Patients in an Observational Cohort Study

PURPOSE

Statins are inhibitors of 3-hydroxy-3-methyl glutaryl coenzyme A (HMG-CoA) reductase, which is involved in cholesterol synthesis. The major side effects of statins include muscle- and liver-related toxicity. Muscle toxicity is highly associated with polymorphisms in cytochrome P450 proteins (CYPs), as predicted by pharmacogenomics. However, the mechanisms of hepatotoxicity are not well understood. Due to differences in cholesterol metabolism, statins are well tolerated in mice. In contrast, hamsters exhibit metabolic traits similar to humans and are suitable for studying the hepatotoxicity of statins.

METHODS

We investigated the effect of rosuvastatin (RSV) on liver damage in wild-type (WT) hamsters fed a high-cholesterol diet (HCD) and LDLR knockout (LDLR^-/-) hamsters that developed spontaneous hypercholesterolemia. Two cohorts of clinical subjects (clinical registry number: 2017001) taking atorvastatin (ATV) were recruited for direct (assessment of cholesterol intake individually, n = 44) and indirect (celebratory meals/holiday season, n = 1993) examination of dietary cholesterol intake and liver damage, as indicated by elevation of alanine aminotransferase (ALT).

RESULTS

RSV at a dose of 10 mg/kg caused fatal liver damage only in HCD-fed WT hamsters, while LDLR^-/- hamsters with the same cholesterol levels were resistant to this toxic effect. In the human studies, we observed that the incidence of hepatic toxicity in patients receiving long-term ATV treatment was higher in patients with greater dietary cholesterol intake and in patients who consumed more food during Chinese holidays.

CONCLUSION

Our results propose, for the first time, that dietary cholesterol significantly contributes to statin-related hepatotoxicity, providing valuable insight into the clinical use of statins.

Interleukin-22 Inhibits Respiratory Syncytial Virus Production by Blocking Virus-Mediated Subversion of Cellular Autophagy

Respiratory syncytial virus (RSV) infection can cause severe bronchiolitis in infants requiring hospitalization, whereas the elderly and immunocompromised are prone to RSV-induced pneumonia. RSV primarily infects lung epithelial cells. Given that no vaccine against RSV is currently available, we tested the ability of the epithelial-barrier protective cytokine interleukin-22 (IL-22) to control RSV production. When used in a therapeutic modality, IL-22 efficiently blunted RSV production from infected human airway and alveolar epithelial cells and IL-22 administration drastically reduced virus titer in the lungs of infected newborn mice. RSV infection resulted in increased expression of LC3B, a key component of the cellular autophagic machinery, and knockdown of LC3B ablated virus production. RSV subverted LC3B with evidence of co-localization and caused a significant reduction in autophagic flux, both reversed by IL-22 treatment. Our findings inform a previously unrecognized anti-viral effect of IL-22 that can be harnessed to prevent RSV-induced severe respiratory disease.

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RSV infection of lung epithelial cells subverts the cellular autophagic machinery

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RSV infection inhibits autophagic flux in infected cells

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IL-22 inhibits RSV production from human lung epithelial cells and in neonatal mice

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IL-22 blocks RSV-LC3B co-localization and restores cellular autophagic flux

Advanced Role of Neutrophils in Common Respiratory Diseases

Respiratory diseases, always being a threat towards the health of people all over the world, are most tightly associated with immune system. Neutrophils serve as an important component of immune defense barrier linking innate and adaptive immunity. They participate in the clearance of exogenous pathogens and endogenous cell debris and play an essential role in the pathogenesis of many respiratory diseases. However, the pathological mechanism of neutrophils remains complex and obscure. The traditional roles of neutrophils in severe asthma, chronic obstructive pulmonary diseases (COPD), pneumonia, lung cancer, pulmonary fibrosis, bronchitis, and bronchiolitis had already been reviewed. With the development of scientific research, the involvement of neutrophils in respiratory diseases is being brought to light with emerging data on neutrophil subsets, trafficking, and cell death mechanism (e.g., NETosis, apoptosis) in diseases. We reviewed all these recent studies here to provide you with the latest advances about the role of neutrophils in respiratory diseases.

Ongoing developments in RSV prophylaxis: a clinician's analysis

Respiratory syncytial virus (RSV) is the most common respiratory pathogen in infants and young children worldwide. Lower respiratory tract infection due to RSV is one of the most common causes of hospitalization for infants, especially those born premature or with chronic lung or heart disease. Furthermore, RSV infection is an important cause of morbidity in adults, particularly in the elderly and immunocompromised individuals. The acute phase of this infection is often followed by episodes of wheezing that recur for months or years and usually lead to a physician diagnosis of asthma. RSV was discovered more than 50 years ago, and despite extensive research to identify pharmacological therapies, the most effective management of this infection remains supportive care. The trial of a formalin-inactivated RSV vaccine in the 1960s resulted in priming the severe illness upon natural infection. Currently, Palivizumab is the only available option for RSV prophylaxis, and because of restricted clinical benefits and high costs, it has been limited to a group of high-risk infants. There are several ongoing trials in preclinical, Phase-I, Phase-II, or Phase-III clinical stages for RSV vaccine development based on various strategies. Here we review the existing available prophylactic options, the current stages of RSV vaccine clinical trials, different strategies, and major hurdles in the development of an effective RSV vaccine.