Air pollution and bronchiolitis: a case-control study in Antwerp, Belgium.

This case-control study aimed to investigate the association between short-term (1 to 5 days) and medium-term (31 days) exposure to air pollutants (PM2.5, PM10, BC, NO2) at home/daycare and the risk of 'severe bronchiolitis' (defined as 'requiring hospitalization for bronchiolitis') in children under 2 years in Antwerp, Belgium. We included 118 cases and 79 controls admitted to three general hospitals from October 2020 to June 2021. Exposure levels were predicted using an interpolation model based on fixed measuring stations. We used unconditional logistic regression analysis to assess associations, with adjustment for potential confounders. There were hardly any significant differences in the day-to-day air pollution values between cases and controls. Medium-term (31 days) exposure to PM2.5, PM10, and NO2 was however significantly higher in cases than controls in univariate analysis. Logistic regression revealed an association between severe bronchiolitis and interquartile range (IQR) increases of PM2.5 and PM10 at home and in daycare, as well as IQR increases of NO2 in daycare. Controls were however overrepresented in low pollution periods. Time-adjustment reduced the odds ratios significantly at home for PM2.5 and PM10 (aOR 1.54, 95%CI 0.51-4.65; and 2.69, 95%CI 0.94-7.69 respectively), and in daycare for. PM2.5 (aOR 2.43, 95%CI 0.58-10.1). However, the association between severe bronchiolitis and medium-term air pollution was retained in daycare for IQR increases of PM10 (aOR 5.13, 95%CI 1.24-21.28) and NO2 (aOR 3.88, 95%CI 1.56-9.61) in the time-adjusted model.  Conclusion: This study suggests a possible link between severe bronchiolitis and medium-term (31 days) air pollution exposure (PM10 and NO2), particularly in daycare. Larger studies are warranted to confirm these findings. What is Known: • Bronchiolitis is a leading cause of hospitalization in infants globally and causes a yearly seasonal wave of admissions in paediatric departments worldwide. • Existing studies, mainly from the USA, show heterogeneous outcomes regarding the association between air pollution and bronchiolitis. What is New: • There is a possible link between severe bronchiolitis and medium-term (31 days) air pollution exposure (PM10 and NO2), particularly in daycare. • Larger studies are needed to validate these trends.

Probabilistic Linkage Creates a Novel Database to Study Bronchiolitis Care in the PICU.

OBJECTIVES: Lack of a comprehensive database containing diagnosis, patient and clinical characteristics, diagnostics, treatments, and outcomes limits needed comparative effectiveness research (CER) to improve care in the PICU. Combined, the Pediatric Hospital Information System (PHIS) and Virtual Pediatric Systems (VPS) databases contain the needed data for CER, but limits on the use of patient identifiers have thus far prevented linkage of these databases with traditional linkage methods. Focusing on the subgroup of patients with bronchiolitis, we aim to show that probabilistic linkage methods accurately link data from PHIS and VPS without the need for patient identifiers to create the database needed for CER. METHODS: We used probabilistic linkage to link PHIS and VPS records for patients admitted to a tertiary children's hospital between July 1, 2017 to June 30, 2019. We calculated the percentage of matched records, rate of false-positive matches, and compared demographics between matched and unmatched subjects with bronchiolitis. RESULTS: We linked 839 of 920 (91%) records with 4 (0.5%) false-positive matches. We found no differences in age (P = .76), presence of comorbidities (P = .16), admission illness severity (P = .44), intubation rate (P = .41), or PICU stay length (P = .36) between linked and unlinked subjects. CONCLUSIONS: Probabilistic linkage creates an accurate and representative combined VPS-PHIS database of patients with bronchiolitis. Our methods are scalable to join data from the 38 hospitals that jointly contribute to PHIS and VPS, creating a national database of diagnostics, treatment, outcome, and patient and clinical data to enable CER for bronchiolitis and other conditions cared for in the PICU.

Increased bronchiolitis burden and severity after the pandemic: a national multicentric study.

BACKGROUND: The coronavirus 2019 (COVID-19) related containment measures led to the disruption of all virus distribution. Bronchiolitis-related hospitalizations shrank during 2020-2021, rebounding to pre-pandemic numbers the following year. This study aims to describe the trend in bronchiolitis-related hospitalization this year, focusing on severity and viral epidemiology. METHODS: We conducted a retrospective investigation collecting clinical records data from all infants hospitalized for bronchiolitis during winter (1st September-31th March) from September 2018 to March 2023 in six Italian hospitals. No trial registration was necessary according to authorization no.9/2014 of the Italian law. RESULTS: Nine hundred fifty-three infants were hospitalized for bronchiolitis this last winter, 563 in 2021-2022, 34 in 2020-2021, 395 in 2019-2020 and 483 in 2018-2019. The mean length of stay was significantly longer this year compared to all previous years (mean 7.2 ± 6 days in 2022-2023), compared to 5.7 ± 4 in 2021-2022, 5.3 ± 4 in 2020-2021, 6.4 ± 5 in 2019-2020 and 5.5 ± 4 in 2018-2019 (p < 0.001), respectively. More patients required mechanical ventilation this winter 38 (4%), compared to 6 (1%) in 2021-2022, 0 in 2020-2021, 11 (2%) in 2019-2020 and 6 (1%) in 2018-2019 (p < 0.05), respectively. High-flow nasal cannula and non-invasive respiratory supports were statistically more common last winter (p = 0.001 or less). RSV prevalence and distribution did not differ this winter, but coinfections were more prevalent 307 (42%), 138 (31%) in 2021-2022, 1 (33%) in 2020-2021, 68 (23%) in 2019-2020, 61 (28%) in 2018-2019 (p = 0.001). CONCLUSIONS: This study shows a growth of nearly 70% in hospitalisations for bronchiolitis, and an increase in invasive respiratory support and coinfections, suggesting a more severe disease course this winter compared to the last five years.

Trends in emergency department visits for bronchiolitis, 1993-2019.

INTRODUCTION: Bronchiolitis is a leading indication for pediatric emergency department (ED) visits and hospitalizations. Our objective was to provide a comprehensive review of national trends and epidemiology of ED visits for bronchiolitis from 1993 to 2019 in the United States. METHODS: We retrospectively reviewed the National Hospital Ambulatory Medical Care Survey (NHAMCS) reporting of ED visits for bronchiolitis for children age <2 years from 1993 to 2019. Bronchiolitis cases were identified using billing codes assigned at discharge. The primary outcome was bronchiolitis ED visit rates, calculated using NHAMCS-assigned patient visit weights. We then evaluated for temporal variation in patient characteristics, facility location, and hospitalizations among the bronchiolitis ED visits. RESULTS: There were an estimated 8 million ED visits for bronchiolitis for children <2 years between 1993 and 2019. Bronchiolitis ED visits rates ranged from 28 to 36 per 1000 ED visits from 1993 to 2010 and increased significantly to 65 per 1000 ED visits in the 2017-2019 time period (p < 0.001). There was no significant change over time in patient age, sex, race and ethnicity, insurance status, hospital type, or triage level upon ED presentation. Approximately half of bronchiolitis ED visits occurred in the winter months throughout the study period. CONCLUSION: In this analysis of 27 years of national data, we identified a recent rise in ED visit rates for bronchiolitis, which have almost doubled from 2010 to 2019 following a period of relative stability between 1993 and 2010.

Long-lasting effects of COVID-19 pandemic on hospitalizations and severity of bronchiolitis.

Bronchiolitis is a common cause of hospitalization in infants. The long-lasting impact of hygiene and social behavior changes during the pandemic on this disease is debated. We investigated the prevalence of hospitalized cases, clinical severity, and underlying risk factors before and during pandemic. The study was conducted in 27 hospitals in Italy and included infants hospitalized for bronchiolitis during the following four periods: July 2018-March 2019, July 2020-March 2021, July 2021-March 2022, and July 2022-March 2023. Data on demographics, neonatal gestational age, breastfeeding history, underlying chronic diseases, presence of older siblings, etiologic agents, clinical course and outcome were collected. A total of 5330 patients were included in the study. Compared to 2018-19 (n = 1618), the number of hospitalizations decreased in 2020-21 (n = 121). A gradual increase was observed in 2021-22 (n = 1577) and 2022-23 (n = 2014). A higher disease severity (need and length of O2-supplementation, need for non-invasive ventilation, hospital stay) occurred in the 2021-22 and, especially, the 2022-23 periods compared to 2018-19. This tendency persisted after adjusting for risk factors associated with bronchiolitis severity.   Conclusions: Compared to adults, COVID-19 in infants is often asymptomatic or mildly symptomatic and rarely results in hospitalization. This study indicates that the pandemic has indirectly induced an increased burden of bronchiolitis among hospitalized infants. This shift, which is not explained by the recognized risk factors, suggests the existence of higher infant vulnerability during the last two seasons. What is known: • The pandemic led to a change in epidemiology of respiratory diseases • Large data on severity of bronchiolitis and underlying risk factors before and during COVID-19 pandemic are scarce What is new: • Compared to pre-pandemic period, hospitalizations for bronchiolitis decreased in 2020-21 and gradually increased in 2021-22 and 2022-23 • Compared to pre-pandemic period, higher disease burden occurred in 2021-22 and, especially, in 2022-23. This tendency persisted after adjusting for risk factors associated with bronchiolitis severity • The interplay among viruses, preventive measures, and the infant health deserves to be further investigated.

Chest imaging classification in Mycoplasma pneumoniae pneumonia is associated with its clinical features and outcomes.

BACKGROUND: The imaging findings of Mycoplasma pneumoniae pneumonia (MPP) vary; however, few studies have focused on the relationship of imaging classification with clinical manifestations and outcomes. OBJECTIVE: To prospectively investigate whether chest imaging classification in Mycoplasma pneumoniae pneumonia (MPP) is associated with its clinical features and outcomes. METHODS: A total of 1,401 hospitalized children with MPP were enrolled from January 2019 to December 2021. Imaging findings were categorized as bronchopneumonia and consolidation/atelectasis according to X-ray, and bronchopneumonia, consolidation/atelectasis, bronchiolitis, and mosaic pattern according to computed tomography (CT). Clinical characteristics and outcomes of patients with different imaging classifications were prospectively analyzed based on electronic medical records. RESULTS: Bronchopneumonia was the most common finding (59.6%), while consolidation/atelectasis was the most severe group. Clinical manifestations and laboratory indicators for the consolidation/atelectasis group included serious abnormalities. Further, outcomes of the patients were worse, including having longer total durations of fever and hospitalization, greater hospitalization expenses, and a higher likelihood of developing refractory MPP, necrotizing pneumonia, and bronchiolitis obliterans (BO) in this group. The incidence of bronchiolitis, a disease characterized by a high prevalence of fever, moist rales, and an atopic constitution, tended to increase after the coronavirus disease pandemic and predisposed patients to BO. A mosaic pattern occurred in allergic and young individuals, with wheezing as the main manifestation, with patients having relatively mild symptoms and good outcomes. CONCLUSION: Different imaging classifications have different clinical features and clinical outcomes; thus, formulating an imaging-based classification system is of great clinical value.

Acute Bronchiolitis: The Less, the Better?

BACKGROUND: Acute bronchiolitis is a viral infection of the lower respiratory tract affecting infants aged under 12 months, variably presenting with respiratory distress, diffuse crackles and inflammatory wheezing. The main causative agent is Respiratory Syncytial Virus (RSV). The diagnosis is clinical and treatment mainly supportive. Despite the availability of more than 30 international guidelines, consistent management recommendations are lacking and considerable variability in patients' care persists among different providers. OBJECTIVE: To review and describe current knowledge about epidemiology, physiopathology, clinic, diagnosis and management of acute bronchiolitis, with particular emphasis on updated evidence and future perspectives in terms of treatment and prevention. METHODS AND RESULTS: We searched Cochrane for systematic reviews and PubMed for scientific articles published in the last 10 years, using a combination of the following search terms: "bronchiolitis", "respiratory syncytial virus", "epidemiology", "risk factors", "severity", "diagnosis", "clinic", "diagnostic imaging", "management", "asthma", "wheezing", "bronchodilator", "steroids", "hypertonic saline", "oxygen", "blood gas analysis", "HHHFNC", "rehydration", "enteral feeding", "parenteral hydration", "prevention", "vaccine" and "COVID-19 or SARS-CoV2". We accordingly performed a deep and extensive selection of the most updated and considerable literature on the matter, summarizing the most significant evidence concerning all aspects of acute bronchiolitis (epidemiology, clinic, diagnosis, management and prevention). Furthermore, we examined references and available guidelines from UK, USA, Canada, Italy and Spain. Results are extensively discussed below. CONCLUSION: Although acute bronchiolitis has been a widely known disease for decades, its therapeutic approach remained unchanged and essentially limited to respiratory and metabolic support. Despite the abundance of studies, there is no significant evidence concerning therapeutic alternatives (e.g. steroids, inhaled hypertonic solution), which are therefore not recommended. According to most recent data, "acute bronchiolitis" definition encompasses a plethora of different clinical entities related to each subject's genetic and immune predisposition. Therefore, future research should focus on the precise characterization of such subcategories in order to individualize therapeutic management and ensure the most appropriate evidence-based care.

Association of Socioeconomic Factors and Severity of Bronchiolitis Hospitalizations.

It is unclear if socioeconomic status (SES) factors influence severity of illness of patients hospitalized with bronchiolitis. This study was conducted to identify SES factors including the Center for Disease Control and Prevention's Social Vulnerability Composite Index (SVI), estimated income, proportion of minority, proportion of living below poverty, insurance status, and number of household members associated with length of stay (LOS) and intensive care unit admission. Infants hospitalized at a tertiary care urban center for bronchiolitis were identified using International Classification of Diseases codes. Federal information processing system codes were identified from home address and paired with SVI and 2018 census tract. Other measures of SES were obtained from the Federal Financial Institutions Examination Council. Number of household members, insurance, age, sex, and history of prematurity were recorded from patient chart. Length of stay was modeled with mixed effects negative binomial regression and pediatric intensive care unit (PICU) admission with mixed effects logistic regression with random intercept at the census tract and adjustment for clinical factors. A total of 417 infants had median age of 144 days (interquartile range (IQR): 61, 357) and 136 (33%) were born premature. Median LOS was 62 hours (24, 136) with 97 (23%) patients admitted to the PICU. Median household members were 4 (4, 5). For each increase in household member, there was 7% increase in LOS (incidence rate ratio 1.07, 95% confidence interval: 1-1.14, P = .038). Social Vulnerability Composite Index, subcategories, insurance status, estimated income, percent of minority, and percent of poverty did not show any associations with length of hospitalization or PICU admission. Increasing number of household members may be associated with increased bronchiolitis hospital LOS. We find no associations with other SES measures.

Head-to-Head Comparison Between Respiratory Syncytial Virus and Human Metapneumovirus Bronchiolitis in the Setting of Increased Viral Testing.

We compared the epidemiology, severity and management of hospitalized respiratory syncytial virus (n = 305) and human metapneumovirus (n = 39) bronchiolitis in a setting with high respiratory virus testing (95% of admissions tested). Respiratory syncytial virus-positive infants were younger and tended to require more hydration support and longer hospital stays compared to human metapneumovirus-positive infants. Respiratory support requirements were similar between groups despite significant age differences.

Bronchiolitis trends in out-of-hospital urgent care services in the Community of Madrid: Observational study, 2016-2023.

INTRODUCTION: Bronchiolitis poses a considerable challenge during its seasonal peak, overwhelming the material and human resources available to care for affected patients. As a result, interhospital transfers increase exponentially. We did not find any studies analysing the characteristics of patients with bronchiolitis managed in out-of-hospital urgent care (OHUC) services and the impact of the COVID-19 pandemic on the epidemiology of bronchiolitis. OBJECTIVE: To establish the characteristics of paediatric and neonatal patients with acute bronchiolitis (AB) managed in OHUC services in the Community of Madrid and to analyse the impact of the COVID-19 pandemic on the epidemiology of bronchiolitis. METHODS: Retrospective cross-sectional observational and descriptive study carried out in OHUC settings in the Community of Madrid between 2016 and 2023. We included patients with a diagnosis of acute bronchiolitis based on the ICD-10 codes documented in the electronic records of urgent care visits and interhospital transports. We collected data on sociodemographic, clinical and treatment (ventilation and medication) variables. RESULTS: The sample included 630 patients with AB: 343 managed in non-neonatal OHUC (non-neo) services and 287 by the mobile neonatal intensive care unit transport team (NTT). The median age was 3.7 months (IQR, 2.8-4.7) in patients in the non-neo OHUC group and 19 days (IQR, 14.2-23.7) in the NTT group. There was a statistically significant increase in age in the 2020/2021 season in the non-neo OHUC group. The severity score was significantly higher in the NTT group. There was an unusual peak in bronchiolitis cases in June 2021, coinciding with the end of the 4th wave of the COVID-19 pandemic. The incidence of bronchiolitis was highest after the 6th wave of the pandemic (13.5 cases per 10 000 children aged < 2 years). CONCLUSIONS: The median age of paediatric patients with AB managed in OHUC services increased following the end of the lockdown imposed due to the COVID-19 pandemic, which was probably associated with the lack of exposure to the viruses that cause it. This also may explain why the incidence of bronchiolitis was highest in the season following the 6th wave of the pandemic. The severity score was higher in neonatal patients. Epidemiological surveillance, the introduction of protocols and the implementation of an ongoing training programme for non-specialized health care staff involved in the transport of these patients could improve their management.

Asthmalitis? Diagnostic Variability of Asthma and Bronchiolitis in Children <24 Months.

BACKGROUND AND OBJECTIVES: Bronchiolitis and asthma have similar acute clinical presentations in young children yet have opposing treatment recommendations. We aimed to assess the role of age and other factors in the diagnosis of bronchiolitis and asthma in children <24 months of age. METHODS: We conducted a retrospective cross-sectional analysis of the Pediatric Health Information System database. We included children aged <2 years diagnosed with bronchiolitis, asthma, wheeze, or bronchospasm in emergency department or hospital encounters from 2017 to 2021. We described variation by age and between institutions. We used mixed-effects models to assess factors associated with a non-bronchiolitis diagnosis in children 12 to 23 months of age. RESULTS: We included 554 158 encounters from 42 hospitals. Bronchiolitis made up 98% of encounters for children <3 months of age, whereas asthma diagnoses increased with age and were included in 44% of encounters at 23 months of age. Diagnosis patterns varied widely between hospitals. In children 12 to 23 months of age, the odds of a non-bronchiolitis diagnosis increased with month of age (odds ratio [OR] 1.13, 95% confidence interval [CI] 1.12-1.13), male sex (OR 1.37, 95% CI 1.35-1.40), non-Hispanic Black race (OR 1.54, 95% CI 1.50-1.58), number of previous encounters (OR 2.73, 95% CI 2.61-2.86, for 3 or more encounters), and previous albuterol use (OR 2.24, 95% CI 2.16-2.32). CONCLUSIONS: Non-bronchiolitis diagnoses and the use of inhaled bronchodilators and systemic steroids for acute wheezing respiratory illness increase with month of age in children aged 0 to 23 months. Better definitions of clinical phenotypes of bronchiolitis and asthma would allow for more appropriate treatment in acute care settings, particularly in children 12 to 23 months of age.

Air pollution after acute bronchiolitis is a risk factor for preschool asthma: a nested case-control study.

BACKGROUND: Acute bronchiolitis and air pollution are both risk factor of pediatric asthma. This study aimed to assess subsequent exposure to air pollutants related to the inception of preschool asthma in infants with acute bronchiolitis. This study aimed to assess subsequent exposure to air pollutants related to the inception of preschool asthma in infants with acute bronchiolitis. METHODS: A nested case-control retrospective study was performed at the Kaohsiung Medical University Hospital systems between 2009 and 2019. The average concentration of PM10, PM2.5, SO2, NO, NO2, and NOX was collected for three, six, and twelve months after the first infected episode. Adjusted regression models were employed to evaluate the association between asthma and air pollution exposure after bronchiolitis. RESULTS: Two thousand six hundred thirty-seven children with acute bronchiolitis were included. Exposure to PM10, PM2.5, SO2, NO, NO2, and NOX in the three, six, and twelve months following an episode of bronchiolitis was found to significantly increase the risk of preschool asthma in infants with a history of bronchiolitis.(OR, 95%CI: PM10 = 1.517-1.559, 1.354-1.744; PM2.5 = 2.510-2.603, 2.148-3.061; SO2 = 1.970-2.040, 1.724-2.342; ; NO = 1.915-1.950, 1.647-2.272; NO2 = 1.915-1.950, 1.647-2.272; NOX = 1.752-1.970, 1.508-2.252) In a sensitive analysis of hospitalized infants, only PM10, PM2.5, SO2, and NO were found to have significant effects during all time periods. (OR, 95%CI: PM10 = 1.613-1.650, 1.240-2.140; PM2.5 = 2.208-2.286, 1.568-3.061; SO2 = 1.679-1.622, 1.197-2.292; NO = 1.525-1.557, 1.094-2.181) CONCLUSION: The presence of ambient PM10, PM2.5, SO2 and NO in the three, six, and twelve months following an episode of acute bronchiolitis has been linked to the development of preschool asthma in infants with a history of acute bronchiolitis.

[Influencia de la pandemia de la COVID-19 en la distribución de la bronquiolitis aguda en España.] / Influencia de la pandemia de la COVID-19 en la distribución de la bronquiolitis aguda en España.

OBJECTIVE: Bronchiolitis is the leading cause of hospitalization in children under one year of age, with annual epidemics. Since the onset of the SARS-CoV-2 coronavirus disease pandemic (COVID-19), there has been a change in the transmission of other respiratory viruses. Our aim in this paper was to describe how COVID-19 had affected the distribution of acute bronchiolitis in our country. METHODS: We conducted a retrospective descriptive study of the cases of bronchiolitis treated in a sample of Spanish hospitals belonging to four autonomous communities. A chi-square test and Student's t- test were used to compare epidemiological and demographic variables between patients attending the hospital with bronchiolitis during January 2021-June 2021 with patients attending the hospital in the previous three years (2018-2020). RESULTS: We analyzed 6,124 cases of bronchiolitis (58.8% males and 41.2% females). The mean age was 0.5 years (SD: 0.4). In 2020, we observed a decrease of bronchiolitis cases compared to 2019 of 67%. During 2020 and 2021, the epidemic season started in January-February and peaked in June. During the first half of 2021, the highest percentage of admissions for bronchiolitis associated with RSV infection was observed in hospitals in central Spain corresponding to the Autonomous Community of Madrid (78.5% of admissions). CONCLUSIONS: The COVID-19 pandemic significantly modifies the seasonality of bronchiolitis. In our country, the flow and distribution of the disease are not uniform. It starts in the center of Spain and ends on the coast.

OBJETIVO: La bronquiolitis es la primera causa de hospitalización en menores de un año, presentándose en forma de epidemias anuales. Desde el inicio de la pandemia por la enfermedad causada por el coronavirus SARS-CoV-2 (COVID-19) se ha producido un cambio en la transmisión de otros virus respiratorios. Nuestro objetivo en este trabajo fue describir cómo había afectado la pandemia de la COVID-19 a la distribución de la bronquiolitis aguda en nuestro país. METODOS: Realizamos un estudio descriptivo retrospectivo de los casos de bronquiolitis atendidos en una muestra de hospitales españoles que pertenecían a cuatro comunidades autónomas. Empleado el test chi-cuadrado y la prueba t de Student comparamos variables epidemiológicas y demográficas de los casos de bronquiolitis atendidos durante enero de 2021 y junio 2021, con los tres años anteriores (2018-2020). RESULTADOS: Analizamos 6.124 casos de bronquiolitis (58,8% varones y 41,2% mujeres). La media de edad fue de 0,5 años (DE: 0,4). En 2020 observamos un descenso de casos de bronquiolitis con respecto a 2019 del 67%. Durante 2020 y 2021 la temporada epidémica empezó en enero-febrero y alcanzó su pico máximo en junio. Durante el primer semestre de 2021, el porcentaje más elevado de ingresos por bronquiolitis asociados a infección VRS fue observado en hospitales del centro de España correspondientes a la Comunidad Autónoma de Madrid (78,5% de los ingresos). CONCLUSIONES: La pandemia por la COVID-19 modifica de manera significativa la estacionalidad de la bronquiolitis. En nuestro país, el flujo y distribución de la enfermedad no es uniforme, comenzado por el centro peninsular y, por último, la zona litoral.

Respiratory Syncytial Virus in Outpatient Children with Bronchiolitis: Continuous Virus Circulation During the Nonepidemic Period.

We aimed to estimate the respiratory syncytial virus positivity rate among ambulatory children with bronchiolitis according to the bronchiolitis epidemic period as defined by the French Public Health Institute. The positivity rate was 28.9% during the nonepidemic period and 50.6% during the epidemic period, which suggests continuous virus circulation between bronchiolitis annual peaks.

National Patterns of Outpatient Follow-Up Visits After Emergency Care for Acute Bronchiolitis.

This cohort study examines the frequency of postdischarge follow-up visits among US emergency department encounters for bronchiolitis and assesses whether follow-up was associated with decreased hospital reutilization or increased treatment with nonrecommended medications.

Outcomes of viral coinfections in infants hospitalized for acute bronchiolitis.

BACKGROUND AND OBJECTIVE: The clinical relevance of the detection of multiple respiratory viruses in acute bronchiolitis (AB) has not been established. Our goal was to evaluate the effect of viral coinfections on the progression and severity of AB. METHODS: A retrospective observational study was conducted in a tertiary hospital in Spain from September 2012 to March 2020. Infants admitted for AB with at least one respiratory virus identified by molecular diagnostic techniques were included. A comparison was made between single-virus infections and viral coinfections. The evolution and severity of AB were determined based on the days of hospitalization and admission to the pediatric intensive care unit (PICU). RESULTS: Four hundred forty-five patients were included (58.4% male). The median weight was 5.2 kg (IQR 4.2-6.5), and the median age was 2.5 months (IQR 1.4-4.6). A total of 105 patients (23.6%) were admitted to the PICU. Respiratory syncytial virus (RSV) was the most frequent etiological agent (77.1%). A single virus was detected in 270 patients (60.7%), and viral coinfections were detected in 175 (39.3%), of which 126 (28.3%) had two viruses and 49 (11%) had three or more viruses. Hospital length of stay (LOS) increased in proportion to the number of viruses detected, with a median of 6 days (IQR 4-8) for single infections, 7 days (IQR 4-9) for coinfections with two viruses and 8 days (IQR 5-11) for coinfections with ≥ 3 viruses (p = 0.003). The adjusted Cox regression model showed that the detection of ≥ 3 viruses was an independent risk factor for a longer hospital LOS (HR 0.568, 95% CI 0.410-0.785). No significant association was observed between viral coinfections and the need for PICU admission (OR 1.151; 95% CI 0.737-1.797). CONCLUSIONS: Viral coinfections modified the natural history of AB, prolonging the hospital LOS in proportion to the number of viruses detected without increasing the need for admission to the PICU.

SIGNIFICANCE: What is KnownThe main etiological agent of acute bronchiolitis (AB) is respiratory syncytial virus (RSV); however, other viruses are frequently detected. All viruses may be the sole etiological cause or may occur in association, and a high prevalence of viral coinfection has been described.To date, there are conflicting results on the role of viral coinfections in the severity of bronchiolitis.What is NewViral coinfections influence the progression of AB. The simultaneous detection of 3 or more respiratory viruses is a risk factor for longer hospital stay.The presence of viral coinfections does not condition a greater need for admission to the PICU.

Admissions for Bronchiolitis at Children's Hospitals Before and During the COVID-19 Pandemic.

Importance: The COVID-19 pandemic has been associated with a transient decrease in bronchiolitis hospitalizations compared with prepandemic patterns, but current effects remain unknown. Objective: To analyze changes in patterns of bronchiolitis admissions at US children's hospitals during the 2020-2023 bronchiolitis seasons compared with the 2010-2019 seasons. Design, Setting, and Participants: This retrospective cross-sectional study used data from 41 US children's hospitals in the Pediatric Health Information System database. Bronchiolitis has winter-predominant seasonality, so hospitalizations were grouped according to bronchiolitis season (from July through June). This study included all patients aged younger than 2 years admitted with a diagnosis of bronchiolitis between July 1, 2010, and June 30, 2023. Bronchiolitis seasons from July through June between 2010-2011 and 2019-2020 were classified as the prepandemic era, and seasons between 2020-2021 and 2022-2023 were classified as the pandemic era. Data analysis was performed from July 1, 2010, through June 30, 2023. Exposures: Admission date. Main Outcomes and Measures: The primary outcome was number of hospitalizations for bronchiolitis by season and month. Monthly admission counts from the prepandemic era were transformed into time series and used to train seasonal ensemble forecasting models. Forecasts were compared to monthly admissions during the pandemic era. Results: In this study, there were 400 801 bronchiolitis admissions among 349 609 patients between July 1, 2010, and June 30, 2023. The median patient age was 6 (IQR, 2-12) months; 58.7% were boys and 43.7% were White. Hospitalizations increased gradually during the prepandemic era (median, 29 309 [IQR, 26 196-34 157]), decreased 69.2% (n = 9030) in the 2020-2021 season, and increased 75.3% (n = 51 397) in the 2022-2023 season. Patients in the pandemic era were older than those in the prepandemic era (median, 7 [IQR, 3-14] vs 6 [2-12] months; P < .001). Intensive care unit (ICU) admissions increased from 32.2% (96 245 of 298 535) in the prepandemic era to 36.7% (37 516 of 102 266) in the pandemic era (P < .001). The seasonality of bronchiolitis admissions changed during the pandemic era. Admissions peaked in August 2021 (actual 5036 vs 943 [95% CI, 0-2491] forecasted) and November 2022 (actual 10 120 vs 5268 [95% CI, 3425-7419] forecasted). These findings were unchanged in sensitivity analyses excluding children with complex chronic conditions and excluding repeat admissions. In a sensitivity analysis including all viral lower respiratory tract infections in children aged younger than 5 years, there were 66 767 admissions in 2022-2023 vs 35 623 (31 301-41 002) in the prepandemic era, with the largest increase in children aged 24 to 59 months. Conclusions and Relevance: The findings of this cross-sectional study suggest that bronchiolitis hospitalizations decreased transiently and then increased markedly during the COVID-19 pandemic era. Patients admitted during the pandemic era were older and were more likely to be admitted to an ICU. These findings suggest that bronchiolitis seasonality has not yet returned to prepandemic patterns, and US hospitals should prepare for the possibility of atypical timing again in 2023.

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.

Influencia de la pandemia dela COVID-19 en la distribución de la bronquiolitis aguda en España / Influence of the pandemic of COVID-19 in distribution of acute bronchiolitis in Spain

Fundamentos: La bronquiolitis es la primera causa de hospitalización en menores de un año, presentándose en forma de epidemias anuales. Desde el inicio de la pandemia por la enfermedad causada por el coronavirus SARS-CoV-2 (COVID-19) se ha producido un cambio en la transmisión de otros virus respiratorios. Nuestro objetivo en este trabajo fue describir cómo había afectado la pandemia de la COVID-19 a la distribución de la bronquiolitis aguda en nuestro país. Métodos: Realizamos un estudio descriptivo retrospectivo de los casos de bronquiolitis atendidos en una muestra de hospitales españoles que pertenecían a cuatro comunidades autónomas. Empleado el test chi-cuadrado y la pruebat de Student comparamos variables epidemiológicas y demográficas de los casos de bronquiolitis atendidos durante enero de 2021 y junio 2021, con los tres años anteriores (2018-2020). Resultados: Analizamos 6.124 casos de bronquiolitis (58,8% varones y 41,2% mujeres). La media de edad fue de 0,5 años (DE: 0,4). En 2020 observamos un descenso de casos de bronquiolitis con respecto a 2019 del 67%. Durante 2020 y 2021 la temporada epidémica empezó en enero-febrero y alcanzó su pico máximo en junio. Durante el primer semestre de 2021, el porcentaje más elevado de ingresos por bronquiolitis asociados a infección VRS fue observado en hospitales del centro de España correspondientes a la Comunidad Autónoma de Madrid (78,5% de los ingresos). Conclusiones: La pandemia por la COVID-19 modifica de manera significativa la estacionalidad de la bronquiolitis. En nuestro país, el flujo y distribución de la enfermedad no es uniforme, comenzado por el centro peninsular y, por último, la zona litoral.(AU)

Background: Bronchiolitis is the leading cause of hospitalization in children under one year of age, with annual epidemics. Sincethe onset of the SARS-CoV-2 coronavirus disease pandemic (COVID-19), there has been a change in the transmission of other respiratory viruses. Our aim in this paper was to describe how COVID-19 had affected the distribution of acute bronchiolitis in our country. Methods: We conducted a retrospective descriptive study of the cases of bronchiolitis treated in a sample of Spanish hospitals belonging to four autonomous communities. A chi-square test and Student’s t- test were used to compare epidemiological and demographicvariables between patients attending the hospital with bronchiolitis during January 2021-June 2021 with patients attending the hospital in the previous three years (2018-2020). Results: We analyzed 6,124 cases of bronchiolitis (58.8% males and 41.2% females). The mean age was 0.5 years (SD: 0.4). In 2020, weobserved a decrease of bronchiolitis cases compared to 2019 of 67%. During 2020 and 2021, the epidemic season started in January-February and peaked in June. During the first half of 2021, the highest percentage of admissions for bronchiolitis associated with RSVinfection was observed in hospitals in central Spain corresponding to the Autonomous Community of Madrid (78.5% of admissions).Conclusions: The COVID-19 pandemic significantly modifies the seasonality of bronchiolitis. In our country, the flow and distri-bution of the disease are not uniform. It starts in the center of Spain and ends on the coast.(AU)