Epidemiology, Microbiology and Severity of Bronchiolitis in the First Post-Lockdown Cold Season in Three Different Geographical Areas in Italy: A Prospective, Observational Study

Analysis of the prevalence and clinical features of respiratory syncytial virus infection in a pediatric hospital in Zhejiang Province from 2019 to 2023

The aim of this study was to investigate the epidemiological characteristics of respiratory syncytial virus (RSV) infections in children in Zhejiang from 2019 to 2023. Data from pediatric patients who visited the Children's Hospital of Zhejiang University School of Medicine for RSV infection between 2019 and 2023 were analyzed. Nasopharyngeal swabs were collected for RSV antigen detection, and relevant patient information was collected. Factors such as age were analyzed. A total of 673 094 specimens were included from 2019 to 2023, with a rate of positive specimens of 4.74% (31 929/673 094). The highest rate of positive specimens of 10.82%, was recorded in 2021, while the remaining years had a rate of approximately 3%-5%. In terms of seasonal prevalence characteristics, the rate of positive specimens in 2019, 2020, and 2022 peaked in the winter months at approximately 8% and decreased in the summer months, where the rate of positive specimens remained at approximately 0.5%. In contrast, summer is the peak period for RSV incidence in 2021 and 2023, with the rate of positive specimens being as high as 9%-12%. Based on the prevalence characteristics of gender and age, this study found that the detection rate of positive specimens was higher in boys than in girls in 2019-2023. In 2019-2022, among the different age groups, the highest rate of positive specimens was found in children aged 0 to <6 months, and it decreased with age. In 2023, the rate of positive specimens was above 8% in the 0 to <6 months, 6 to <12 months, and 1-2 years age groups, with the highest rate of positive specimens in the 1-2 years age group, and a gradual decrease in the rate of positive specimens with age for children over 3 years of age. Between 2019 and 2023, the epidemiological pattern of RSV changed. A summer peak was observed in 2021 and 2023.

Management and outcomes of bronchiolitis in Italy and Latin America: a multi-center, prospective, observational study

We aimed to describe differences in the epidemiology, management, and outcomes existing between centers located in countries which differ by geographical location and economic status during to post-pandemic bronchiolitis seasons.  This was a prospective observational cohort study performed in two academic centers in Latin America (LA) and three in Italy. All consecutive children with a clinical diagnosis of bronchiolitis were included, following the same data collection form.  Nine hundred forty-three patients have been enrolled: 275 from the two Latin American Centers (San Jose, 215; Buenos Aires, 60), and 668 from Italy (Rome, 178; Milano, 163; Bologna, 251; Catania, 76). Children in LA had more frequently comorbidities, and only rarely received palivizumab. A higher number of patients in LA had been hospitalized in a ward (64% versus 23.9%, p < 0.001) or in a PICU (16% versus 6.2%, p < 0.001), and children in LA required overall more often respiratory support, from low flow oxygen to invasive mechanical ventilation, except for CPAP which was more used in Italy. There was no significant difference in prescription rates for antibiotics, but a significantly higher number of patients treated with systemic steroids in Italy.

CONCLUSIONS

We found significant differences in the care for children with bronchiolitis in Italy and LA. Reasons behind such differences are unclear and would require further investigations to optimize and homogenize practice all over the world.

WHAT IS KNOWN

• Bronchiolitis is among the commest cause of morbidity and mortality in infants all over the world.

WHAT IS NEW

• There are significant differences on how clinicians care for bronchiolitis in different centers and continents. Differences in care can be principally due to different local practices than differences in patients severity/presentations. • Understanding these differences should be a priority to optime and standardize bronchiolitis care globally.

Epidemiological shifts in bronchiolitis patterns and impact of the COVID-19: A two-season comparative study

BACKGROUND

Bronchiolitis is a common lower respiratory tract infection (LRTI) affecting infants and young children. Respiratory syncytial virus (RSV) has historically been the primary causative agent, but other viruses also contribute to the LRTI epidemiology. Recent changes in epidemiology and clinical patterns due to the coronavirus disease 2019 (COVID-19) pandemic have raised concerns. This study aims to analyze the impact of the pandemic on bronchiolitis epidemiology and severity.

METHODS

Two consecutive bronchiolitis seasons (October 2021 to March 2022 and October 2022 to March 2023) were compared. Data on viral agents, hospitalization duration, clinical severity, and respiratory support requirements were collected from pediatric patients at San Marco Hospital, University of Catania.

RESULTS

In the 2021-2022 season, RSV was the predominant virus (40%), followed by other viruses, with mild clinical outcomes. In the 2022-2023 season, RSV remained prevalent (58.7%), but other viruses, including rhinovirus (RV) and influenza, showed a significant increase (p < .05) in bronchiolitis cases and severity. Notably, RSV-related bronchiolitis did not exhibit greater severity compared to non-RSV cases in the 2022-2023 season, contrary to the previous year.

CONCLUSION

The COVID-19 pandemic appears to have shifted the epidemiological landscape of bronchiolitis, with a peak incidence in November instead of January/February. Non-RSV viruses (RV, influenza A and B, as well as metapneumovirus) have gained prominence, possibly due to viral competition and reduced pandemic-related restrictions. Traditionally, RSV has been the primary pathogen responsible for most bronchiolitis cases. Nonetheless, the findings of this study indicate a shifting landscape in bronchiolitis etiology, with RSV gradually diminishing in its role. Contrary to the previous year, RSV-related bronchiolitis did not exhibit greater severity compared to non-RSV cases in the 2022-2023 season.

Changes in clinical, demographic, and outcome patterns of children hospitalized with non-SARS-CoV-2 viral low respiratory tract infections before and during the COVID pandemic in Rome, Italy

INTRODUCTION

We performed this study aiming to evaluate changes in epidemiology, clinical presentation and outcomes of children hospitalized for viral lower respiratory tract infections (LRTI).

METHODS

We performed a retrospective study of children younger than 18 years of age hospitalized for LRTIs with a positive respiratory viral testing from 2018 to 2022. We compared need of pediatric intensive care unit (PICU), invasive ventilation, and other respiratory support, viral etiologies, clinical presentations, imaging, and laboratory results in the precovid (2018-2019) and covid (2020-2022) period.

RESULTS

A total of 523 were included in the analysis. In the pandemic period, the detection of influenza was 95% less likely to occur (odds ratio [OR]: 0.05; 95% confidence interval [95% CI]: 0.02-0.12; p < .001), likewise the detection of adenovirus was 77% less likely to occur (OR: 0.23; 95% CI: 0.10-0.51; p < .001). In the pandemic period, the number of codetections increased from 15.52% in 2018 to 57.25% in 2022, resulting in a significantly increasing trend (p < .001). The odds of transfer to PICU was more than five times greater during the pandemic period (OR: 5.31; 95% CI: 1.78-15.86; p = .003).

CONCLUSIONS

We found that the pattern of LRTI in children during COVID-19 pandemic significantly changed in terms of etiologies and increased severity.

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.

Impact of SARS-CoV-2 Pandemic and Lockdown on the HRSV Circulation: Experience of Three Spoke Hospitals in Northern Italy

The SARS-CoV-2 Pandemic affected the global epidemiology of respiratory infections, including Human Respiratory Syncytial Virus (HRSV), thanks to state governments' implementation of mitigation strategies, like the promotion of face masks and lockdowns. However, after the Pandemic, the dramatic resurge of these diseases was reported worldwide. Our retrospective study, involving three Spoke Pediatric Departments, includes all the infants under one year of age hospitalized for HRSV bronchiolitis in a period before the Pandemic period (2017-2020), during the SARS-CoV-2 Pandemic (2020-2021), and after the Pandemic (2021-2023). The primary aim was to analyze the temporal trend of HRSV in these three periods. Then, the clinical and epidemiological characteristics were analyzed to highlight the clinical differences in the affected patients, in the severity of the infections, and in the short-term outcomes. Ultimately, we analyzed the HRSV prevalence in the global bronchiolitis hospitalization over the reported periods. Overall, we included 237 patients. Before the Pandemic, the peak was recorded in January and February, while after the Pandemic, the peak was in November and December. A higher prevalence of HRSV was demonstrated after the Pandemic compared to the period before the Pandemic; overall, no difference in severity was reported. In conclusion, an increase in HRSV cases after the Pandemic has been demonstrated with an anticipated peak, while no differences were recorded in severity.

Comparison between the Viral Illness Caused by SARS-CoV-2, Influenza Virus, Respiratory Syncytial Virus and Other Respiratory Viruses in Pediatrics

Respiratory tract infections (RTIs) are the most common infectious syndromes, primarily caused by viruses. The primary objective was to compare the illness courses between historical RTIs and recent SARS-CoV-2 infections. The study cohort consisted of RTI cases evaluated at the Pediatric Emergency Departments of Padua and Bologna, discharged or admitted with microbiologically confirmed viral RTI between 1 November 2018 and 30 April 2019 (historical period) and 1 March 2020 and 30 April 2021 (recent period). We evaluated the risk of oxygen or respiratory support, hospitalization, antibiotic therapy, and complications among different viral infections. The odds ratio (OR) and the 95% confidence intervals (CIs) were estimated through mixed-effect logistic regression models, including a random intercept on the individual and hospital. We identified 767 RTIs: 359 in the historical period compared with 408 SARS-CoV-2 infections. Infections of SARS-CoV-2 had a lower risk of being admitted (OR 0.04, 95% CI 0.03-0.07), receiving respiratory support (OR 0.19, 95% CI 0.06-0.58), needing antibiotic therapy (OR 0.35, 95% CI 0.22-0.56) and developing complications (OR 0.27, 95% CI 0.14-0.51) compared to all other viral RTIs. COVID-19 in children is clinically similar to other viral RTIs but is associated with a less severe infection course. Thus, most prevention strategies implemented for SARS-CoV-2 should still be considered during RSV and Influenza epidemics.

Respiratory syncytial virus: can we still believe that after pandemic bronchiolitis is not a critical issue for public health?

Respiratory syncytial virus (RSV) is the leading cause of lower respiratory tract infection among infants and young children, resulting in annual epidemics worldwide. Since the beginning of the COVID-19 pandemic, non-pharmacological interventions were applied, interfering with the circulation of most respiratory viruses, including RSV. The aim of this study is to analyze the RSV infection trend among hospitalized infants during the actual epidemic season (2022-2023) in comparison with the last pre-pandemic season (2018-2019), in order to outline whether significant differences emerge due to COVID-19 pandemia. We retrospectively reviewed medical data on infants hospitalized at the Bambino Gesù Children's Hospital with diagnosis of bronchiolitis in the current epidemic season and in the last pre-pandemic season, 2018-2019. RSV remains the main etiological agent of bronchiolitis in terms of frequency and severity of infections in the ongoing epidemic season. The first RSV case of the 2022-2023 season was detected at week 42 vs week 47 in the 2018-2019 season. The length of epidemic season was of 17 weeks in 2022-2023 vs 18 weeks in 2018-2019. Comparing the two seasons, age at admission was significantly higher in the current season (median age 2022-2023 65 days vs median age 2018-2019 58 days), but the disease severity was similar.       Conclusions: The 2022-2023 bronchiolitis season in Italy started earlier than the usual pre-pandemic seasons but seasonality pattern may be going back to the pre-pandemic one. This season was not more severe than the previous ones. The impact of RSV disease on health care systems and costs remains a critical issue. What is Known: • RSV is one of the major leading causes of hospitalization among children aged less than 3 months. SarsCOV2 pandemic interfered with the seasonal circulation of most respiratory viruses, Including RSV. What is New: • The 2022-2023 bronchiolitis season in Italy started and peaked earlier than the usual pre-pandemic seasons but seasonality pattern may be realigning to the pre-pandemic one. The impact of RSV disease on health care systems and costs is concerning.

Respiratory Syncytial Virus: Willingness towards a Future Vaccine among Pregnant Women in Italy

BACKGROUND

This cross-sectional survey was designed to evaluate pregnant women's awareness regarding Respiratory Syncytial Virus (RSV) infection and willingness to receive the vaccine during pregnancy and to vaccinate their newborn against RSV.

METHODS

An anonymous survey was administered from 20 April to 30 June 2023, to pregnant women aged ≥ 18 years attending gynecology wards of randomly selected public hospitals in southern Italy. A minimum sample size of 427 participants was calculated. The survey assessed women's socio-demographic characteristics, health-related information, their source(s) of information, and attitudes regarding RSV.

RESULTS

A total of 490 women participated. Those who were married/cohabiting, with a high-school degree compared to those who had a university degree, and those who needed additional information were more concerned that the newborn could acquire the RSV infection. The perceived utility of a future RSV vaccine administered during pregnancy was higher among those who were married/cohabiting, with a university degree, those with very good perceived health status, those who received information from healthcare workers, and those who needed additional information. Only 45.9% were willing to be vaccinated during pregnancy, and this was more likely among those with a university degree, with a very good perceived health status, who had received information from healthcare workers, and who needed more information. Finally, almost two-thirds (61.1%) were willing to vaccinate their newborn, and this was more likely among women with a university degree, with a very good perceived health status, and who needed additional information.

CONCLUSIONS

An education campaign regarding RSV infection and its vaccine is needed in order to improve women's perception and to support healthcare workers in promoting it when it will be available.

Association of COVID-19 with respiratory syncytial virus (RSV) infections in children aged 0-5 years in the USA in 2022: a multicentre retrospective cohort study

OBJECTIVE

To investigate whether COVID-19 infection was associated with increased risk for incident respiratory syncytial virus (RSV) infections and associated diseases among young children that might have contributed to the 2022 surge of severe paediatric RSV cases in the USA.

DESIGN

This is a retrospective population-based cohort study. Five outcomes were examined, including overall RSV infection, positive lab test-confirmed RSV infection, clinically diagnosed RSV diseases, RSV-associated bronchiolitis and unspecified bronchiolitis. Risk ratio (RR) and 95% CI of the outcomes that occurred during the 2022 and 2021 RSV seasons were calculated by comparing propensity-score matched cohorts.

SETTING

Nationwide multicentre database of electronic health records (EHRs) of 61.4 million patients in the USA including 1.7 million children 0-5 years of age, which was accessed through TriNetX Analytics that provides web-based and secure access to patient EHR data from hospitals, primary care and specialty treatment providers.

PARTICIPANTS

The study population consisted of 228 940 children of 0-5 years with no prior RSV infection who had medical encounters in October 2022. Findings were replicated in a separate study population of 370 919 children of 0-5 years with no prior RSV infection who had medical encounters in July 2021-August 2021 during a non-overlapping time period.

RESULTS

For the 2022 study population (average age 2.4 years, 46.8% girls, 61% white, 16% black), the risk for incident RSV infection during October 2022-December 2022 was 6.40% for children with prior COVID-19 infection, higher than 4.30% for the matched children without COVID-19 (RR 1.40, 95% CI 1.27 to 1.55); and among children aged 0-1 year, the overall risk was 7.90% for those with prior COVID-19 infection, higher than 5.64% for matched children without (RR 1.40, 95% CI 1.21 to 1.62). For the 2021 study population (average age 2.2 years, 46% girls, 57% white, 20% black), the risk for incident RSV infection during July 2021-December 2021 was 4.85% for children with prior COVID-19 infection, higher than 3.68% for the matched children without COVID-19 (RR 1.32, 95% CI 1.12 to 1.56); and 7.30% for children aged 0-1 year with prior COVID-19 infection, higher than 4.98% for matched children without (RR 1.47, 95% CI 1.18 to 1.82).

CONCLUSION

COVID-19 was associated with a significantly increased risk for RSV infections among children aged 0-5 years in 2022. Similar findings were replicated for a study population of children aged 0-5 years in 2021. Our findings suggest that COVID-19 contributed to the 2022 surge of RSV cases in young children through the large buildup of COVID-19-infected children and the potential long-term adverse effects of COVID-19 on the immune and respiratory system.

Comparative Analysis of Pediatric Hospitalizations during Two Consecutive Influenza and Respiratory Virus Seasons Post-Pandemic

BACKGROUND

The COVID-19 pandemic has had a significant impact on the epidemiology of respiratory viruses. Non-pharmaceutical interventions (NPIs) led to a dramatic reduction in respiratory infections. However, the long-term effects on respiratory virus epidemiology remain unclear.

MATERIALS AND METHODS

We conducted a comparative study on hospitalized pediatric patients with respiratory illness during two seasons: 1 October 2021 to 15 March 2022 and 1 October 2022 to 15 March 2023. We compared the type of virus, mean duration of hospitalization, and disease severity.

RESULTS

In the first season, 47.1% of patients (65/138) tested positive for at least one respiratory virus, with respiratory syncytial virus (RSV) being the most frequent (23.2%). In the second season, 82.9% of patients (102/123) tested positive, with RSV and Rhinovirus being the most prevalent (28.38% and 27.03%, respectively). Other viruses, such as Influenza A/B, Metapneumovirus, and Adenovirus, also showed increased prevalence. Disease severity and mean duration of hospitalization were similar between the two seasons.

CONCLUSIONS

Our study highlights increased prevalence in respiratory viruses, including RSV and Rhinovirus, following the easing of NPIs. The prevalence in respiratory viruses, including RSV and Rhinovirus, increased in the second season compared to the first one. Interestingly, RSV's peak incidence shifted from February to November. The emergence of rhinovirus as the most prevalent respiratory virus during certain months suggests viral competition and dynamic changes in viral circulation. The overall severity of respiratory infections remained relatively stable between the seasons.

2021/22 and 2022/23 Post-Pandemic Bronchiolitis Seasons in Two Major Italian Cities: A Prospective Study

Objectives: Bronchiolitis remains a major cause of morbidity and mortality in children under 24 months. During the first year of the pandemic, non-pharmacological interventions resulted in a significant reduction of bronchiolitis cases. Early in 2021, a rebound of bronchiolitis was reported with a description of out-of-season outbreaks. In this study, we prospectively evaluated the impact of bronchiolitis in two Italian University centers located in different geographical areas, aiming to compare two post-pandemic bronchiolitis seasons (2021/22 and 2022/23) in terms of severity, outcomes, microbiology and temporal distribution. Methods: This was a bicentric prospective observational cohort study. All consecutive children under 24 months of age assessed in the participating institutions during the specified seasons and receiving a clinical diagnosis of bronchiolitis were included. Results: A total of 900 patients were enrolled. Patients in the second season were globally younger and had comorbidities less often. Temporal distribution changed between the two seasons. Of the patients, 56% were tested for RSV; 60% of these was positive. Patients with RSV were globally younger (3.5 months vs. 4.9, p < 0.001), more often had a need for any kind of respiratory and fluid support and more often needed ward or PICU admission. At the end of the ED visit, 430 patients were discharged home, 372 (41.3%) were admitted to an inpatient ward and 46 (5.1%) to a pediatric intensive care unit. Conclusions: The 2022/23 post-COVID bronchiolitis was mostly similar to that of 2021/22, and was in line with pre-pandemic expectations.

Comparison between Nasopharyngeal and Saliva Samples for the Detection of Respiratory Viruses in Children with Acute Lower Respiratory Tract Infections: A Pilot Study

PURPOSE

During the COVID-19 pandemic, the use of salivary swabs (SS) to detect the SARS-CoV-2 virus has been implemented and widely studied in adults and children. However, the role of SS in detecting other common respiratory viruses in children is poorly investigated.

METHODS

Children younger than 18 years of age admitted with respiratory signs and symptoms underwent both nasopharyngeal and SS procedures. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of SS were calculated, considering the nasopharyngeal swab result as the gold standard.

RESULTS

A total of 83 patients (44 females, 53%) underwent both nasopharyngeal and SS procedures. Overall, the sensitivity of SS was 49.4%. Sensitivity according to different respiratory viruses ranged from 0% to 71.43%, while the specificity ranged from 96% to 100%. Negative predictive value ranged from 68.06% to 98.8%, while positive predictive value ranged from 0 to 100%. SS sensitivity in patients younger than 12 months of age was 39.47%, while in patients older than or equal to 12 months of age it was 57.78%. Patients with negative SS had a significantly lower median age (8.5 months (15.25) vs. 23 months (34), p = 0.001) and a significantly lower quantity of median saliva collected for salivary analysis (0 μL (213) vs. 300 μL (100), p < 0.001).

CONCLUSIONS

SS has a relatively low sensitivity in detecting common respiratory viruses in children with LRTI, with a lower probability in younger children (and in particular those younger than 6 months of age) or those from whom we have collected lesser amounts of saliva. New strategies to improve saliva collection are needed for testing on a larger study population.

Fluid balance in critically ill children with lower respiratory tract viral infection: a cohort study

BACKGROUND

Increasing evidence has associated positive fluid balance of critically ill patients with poor outcomes. The aim of this study was to explore the pattern of daily fluid balances and their association with outcomes in critically ill children with lower respiratory tract viral infection.

METHODS

A retrospective single-center study was conducted, in children supported with high-flow nasal cannula, non-invasive ventilation, or invasive ventilation. Median (interquartile range) daily fluid balances, cumulative fluid overload (FO) and peak FO variation, indexed as the % of admission body weight, over the first week of Pediatric Intensive Care Unit admission, and their association with the duration of respiratory support were assessed.

RESULTS

Overall, 94 patients with a median age of 6.9 (1.9-18) months, and a respiratory support duration of 4 (2-7) days, showed a median (interquartile range) daily fluid balance of 18 (4.5-19.5) ml/kg at day 1, which decreased up to day 3 to 5.9 (- 14 to 24.9) ml/kg and increased to 13 (- 11 to 29.9) ml/kg at day 7 (p = 0.001). Median cumulative FO% was 4.6 (- 0.8 to 11) and peak FO% was 5.7 (1.9-12.4). Daily fluid balances, once patients were stratified according to the respiratory support, were significantly lower in those requiring mechanical ventilation (p = 0.003). No correlation was found between all examined fluid balances and respiratory support duration or oxygen saturation, even after subgroup analysis of patients with invasive mechanical ventilation, or respiratory comorbidities, or bacterial coinfection, or of patients under 1 year old.

CONCLUSIONS

In a cohort of children with bronchiolitis, fluid balance was not associated with duration of respiratory support or other parameters of pulmonary function.

The bronchiolitis epidemic in 2021-2022 during the SARS-CoV-2 pandemic: experience of a third level centre in Northern Italy

BACKGROUND

The aim of this study is to compare the 2021-2022 bronchiolitis season to the four previous years (2017-2018, 2018-2019, 2019-2020, 2020-2021) to see if there was an anticipation of the peak, an overall increase of cases, and an increased need of intensive care.

METHODS

A retrospective single-centre study in the San Gerardo Hospital Fondazione MBBM, Monza, Italy was performed. Emergency Departments (ED) visits of patients aged < 18 years and ≤ 12 months were analyzed: the incidence of bronchiolitis on total assessments, the urgency level at triage and the hospitalization rate were compared. Data of children admitted to the Pediatric Department due to bronchiolitis were analyzed in terms of need of intensive care, respiratory support (type and duration), length of hospital stay, main etiological agent, patient characteristics.

RESULTS

During 2020-2021 (first pandemic period) an important reduction in the ED attendance for bronchiolitis was observed, while in 2021-2022 there was an increase in incidence of bronchiolitis (13% of visits in infants < 1 year) and in the rate of urgent accesses (p = 0.0002), but hospitalization rates did not differ compared to previous years. Furthermore, an anticipated peak in November 2021 was observed. In the 2021-2022 cohort of admitted children to the Pediatric Department, a statistically significative increased need of intensive care unit was detected (Odds Ratio 3.1, 95% CI 1.4-6.8 after adjustment for severity and clinical characteristics). Instead, respiratory support (type and duration) and length of hospital stay did not differ. RSV was the main etiological agent and RSV-bronchiolitis determined a more severe infection (type and duration of breathing support, intensive care need and length of hospital stay).

CONCLUSIONS

During Sars-CoV-2 lockdowns (2020-2021), there was a dramatic decrease of bronchiolitis and others respiratory infections. In the following season, 2021-2022, an overall increase of cases with an anticipated peak was observed and data analysis confirmed that patients in 2021-2022 required more intensive care than children in the four previous seasons.

Bronchiolitis 2021-2022 epidemic: multicentric analysis of the characteristics and treatment approach in 214 children from different areas in Italy

Bronchiolitis causes a remarkable number of hospitalizations; its epidemiology follows that of respiratory syncytial virus (RSV), its main pathogen. The aim of this study was to evaluate the presenting features, treatment approach, and impact of medical therapy in four pediatric hospitals in Italy. Data on infants < 24 months of age hospitalized with bronchiolitis in the 2021-2022 season were collected. Between October 2021 and February 2022, 214 children were admitted. Median hospital stay was 5 days; none of the patients died. The distribution of the presenting features is largely comparable in the 33 (15.8%) RSV-negative versus the 176 (84.2%) RSV-positive children; also, no difference was observed in medical therapy provided: duration of oxygen therapy, administration of steroid, and duration of hospital stay. Systemic steroids, inhalation, or antibiotic therapy were given to 34.6%, 79.4%, and 49.1% of children respectively. Of the 214 patients with bronchiolitis, only 19 (8.8%) were admitted to ICU.   Conclusion: Our data suggest that, irrespective of treatments provided, RSV-positive and RSV-negative children had a similar clinical course. The results of our retrospective study further underline the need to improve adherence to existing guidelines on bronchiolitis treatment. What is Known: • Bronchiolitis is a common diseases with seasonal peak. The outcome is usually favorable but hospitalization and even ICU admission is not exceptional. What is New: • Children with RSV associated bronchiolitis do not have a different course and outcome. The analysis of the 2021-2022 cohort, following COVID pandemic peaking, did not show a different course and outcome. • Adherence to literature recommendation, i.e. to focus on oxygen and hydration therapy while avoiding unnecessary systemic therapy with steroid and antibiotics, should be improved.

Epidemiological and clinical characteristics of respiratory syncytial virus and influenza infections in hospitalized children before and during the COVID-19 pandemic in Central China

Background

Globally, the epidemiology of non-SARS-CoV-2 respiratory viruses like respiratory syncytial virus (RSV) and influenza virus was remarkably influenced by the implementation of non-pharmacological interventions (NPIs) during the COVID-19 pandemic. Our study explored the epidemiological and clinical characteristics of pediatric patients hospitalized with RSV or influenza infection before and during the pandemic after relaxation of NPIs in central China.

Methods

This hospital-based prospective case-series study screened pediatric inpatients (age ≤ 14 years) enrolled with acute respiratory infections (ARI) for RSV or influenza infection from 2018 to 2021. The changes in positivity rates of viral detection, epidemiological, and clinical characteristics were analyzed and compared.

Results

Median ages of all eligible ARI patients from 2018-2019 were younger than those from 2020-2021, so were ages of cases infected with RSV or influenza (RSV: 4.2 months vs. 7.2 months; influenza: 27.3 months vs. 37.0 months). Where the positivity rate for influenza was considerably decreased in 2020-2021 (1.4%, 27/1964) as compared with 2018-2019 (2.9%, 94/3275, P < 0.05), it was increased for RSV (11.4% [372/3275] vs. 13.3% [262/1964], P < 0.05) in the same period. The number of severe cases for both RSV and influenza infection were also decreased in 2020-2021 compared with 2018-2019.

Conclusions

The implemented NPIs have had varied impacts on common respiratory viruses. A more effective prevention strategy for RSV infections in childhood is needed.

Are Lung Ultrasound Features More Severe in Children Diagnosed with Bronchiolitis after the COVID-19 Lockdown Period?

The non-pharmacological measures implemented during the SARS-CoV-2 pandemic disrupted the usual bronchiolitis seasonality. Some authors have speculated that, after the lock down period, there would be an increase in the number and severity of respiratory infections due to the re-introduction of respiratory viruses. We collected clinical, microbiological and lung ultrasound data using the classification of the Italian Society of Thoracic Ultrasound (ADET) in children with bronchiolitis during the pandemic compared to the pre-pandemic period, with the aim of assessing whether the epidemic of bronchiolitis during the pandemic was characterized by a more severe lung involvement documented by lung ultrasound. We enrolled 108 children with bronchiolitis (52 pre-pandemic and 56 COVID-19 period), with a median age of 1.74 months (interquartile range, IQR 1-3.68) and 39.8% were females. Rhinovirus detection and high-flow nasal cannula usage were both increased during the COVID-19 period, although overall need of hospitalization and pediatric intensive care unit admissions did not change during the two periods. Lung ultrasound scores were similar in the two cohorts evaluated. Conclusions: our study suggests that, despite changes in microbiology and treatments performed, lung ultrasound severity scores were similar, suggesting that that bronchiolitis during the pandemic period was no more severe than pre-pandemic period, despite children diagnosed during the pandemic had a higher, but it was not statistically significant, probably, due to small sample size, probability of being admitted.

Activity of a Pediatric Emergency Department of a Tertiary Center in Bologna, Italy, during SARS-CoV-2 Pandemic

During the SARS-CoV-2 pandemic, the pediatric emergency department (ED) of Bologna, Emilia-Romagna, Italy faced a reorganization to better deal with the new clinical needs. We herein describe the main changes in the organization and in the attendances to our pediatric ED. From the 1 March 2020 to the 31 January 2022, 796 children positive for SARS-CoV-2 presented to our pediatric ED, but only 26 required hospitalizations, of which only 9 for COVID-19 related reasons. During this period, we also registered a temporal correlation between multisystem inflammatory syndrome in children (MIS-C) admissions and the peaks of SARS-CoV-2 infection in the Italian population. Respiratory syncytial virus (RSV) remained during last year the viral infection with the highest hospitalization rate. The analysis and description of the changes in the activity of the pediatric ED during the SARS-CoV-2 pandemic may help to better understand the routinary activity and be prepared for any possible new challenge.

Changing Epidemiology of Acute Viral Respiratory Infections in Hospitalized Children: The Post-Lockdown Effect

Several reports highlighted how public health measures aimed at limiting severe acute respiratory syndrome Coronavirus-2 (SARS-CoV-2) circulation have likely contributed to reducing the circulation of other respiratory viruses, particularly during the first year of the COVID-19 pandemic. We evaluated the epidemiology of acute respiratory infections in a large cohort of hospitalized children during the third year of the pandemic (2021−2022). We retrospectively analyzed data from the health records of children (<14 years) hospitalized for acute respiratory infections between 1 July 2021 and 31 March 2022. A total of 1763 respiratory panels were collected. Overall, 1269 (72%) panels hadpositive results for at least one pathogen. Most positive panels (53.8%) belonged to patients aged 1−12 months. The most detected pathogen was respiratory syncytial virus (RSV) (57.8% of positive panels). The RSV peak occurred in November 2021. Nine hundred and forty-five (74.5%) panels were positive for one pathogen while three hundred and twenty-four (25.5%) showed multiple infections. Patients with multiple infections were significantly older than those with a single infection. The 2021−2022 peak of RSV infection in Italy occurred earlier than in the previous pre-pandemic seasons. A high number of children have been hospitalized because of acute viral infections also due to less aggressive viruses.

Resurgence of Respiratory Syncytial Virus Infection During COVID-19 Pandemic Among Children in Shanghai, China

Respiratory syncytial virus (RSV) is the most common pathogen causing acute lower respiratory tract infection (LRTI) in children. RSV usually peaks in winter and declines by early spring in China. The outbreak of coronavirus disease 2019 (COVID-19) was reported to bring changes to the transmission pattern of respiratory pathogens including RSV. Here in this paper, we analyzed RSV-positive nasopharyngeal aspirates from inpatients in the Children’s Hospital of Fudan University from October 2019 to October 2021 and compared the clinical features of the RSV-positive patients before and during COVID-19. We found an atypical upsurge of RSV infection in the late summer of 2021 after a major suppression in 2020. RSV B was the main subtype spreading among children throughout the study. Phylogenetic analysis revealed that all RSV A strains belonged to ON1 genotype and all RSV B strains were BA9 genotype. Deduced amino acid analysis displayed different substitutions in the RSV strains observed before and during COVID-19. Demographic analysis suggested that males and infants aged under 5 months were the main populations infected with RSV by gender and age, respectively. Less severe clinical outcomes were observed in patients during COVID-19 than before the pandemic, especially in RSV B-positive patients. Our findings described the epidemiological changes in RSV infection brought by COVID-19, which further underscored the importance of continuous surveillance of RSV in the shadow of COVID-19 at both local and global scales.

Increased use of high-flow nasal cannulas after the pandemic in bronchiolitis: a more severe disease or a changed physician's attitude?

After the SARS-CoV-2 pandemic, we noticed a marked increase in high-flow nasal cannula use for bronchiolitis. This study aims to report the percentage of children treated with high-flow nasal cannula (HFNC) in various seasons. The secondary outcomes were admissions for bronchiolitis, virological results, hospital burden, and NICU/PICU need. We conducted a retrospective study in four Italian hospitals, examining the medical records of all infants (< 12 months) hospitalized for bronchiolitis in the last four winter seasons (1 September-31 March 2018-2022). In the 2021-2022 winter season, 66% of admitted children received HFNC versus 23%, 38%, and 35% in the previous 3 years. A total of 876 patients were hospitalized in the study periods. In 2021-2022, 300 infants were hospitalized for bronchiolitis, 22 in 2020-2021, 259 in 2019-2020, and 295 in 2018-2019. The percentage of patients needing intensive care varied from 28.7% to 18%, 22%, and 15% in each of the four considered periods (p < 0.05). Seventy-seven percent of children received oxygen in the 2021-2022 winter; vs 50%, 63%, and 55% (p < 0.01) in the previous 3 years. NIV/CPAP was used in 23%, 9%, 16%, and 12%, respectively. In 2021-2020, 2% of patients were intubated; 0 in 2020-2021, 3% in 2019-2020, and 1% in 2018-2019.

CONCLUSION

This study shows a marked increase in respiratory support and intensive care admissions this last winter. While these severity indexes were all driven by medical choices, more reliable indexes such as intubation rate and length of stay did not change. Therefore, we suggest that there is a more aggressive treatment attitude rather than a more severe disease.

WHAT IS KNOWN

• COVID-19 pandemic deeply impacted bronchiolitis epidemiology, reducing hospitalizations to onetenth. In the 2021-2022 winter, bronchiolitis resurged to pre-pandemic numbers in Europe.

WHAT IS NEW

• Bronchiolitis hospitalization rose much faster in the 2021-2022 winter period, peaking at a higher level. Respiratory supports and high-flow nasal cannula increased significantly compared to the pre-pandemic era.