Seasonality of the incidence of bronchiolitis in infants — Brazil, 2016-2022: An interrupted time-series analysis / Sazonalidade da incidência de bronquiolite em lactentes — Brasil, 2016-2022: Uma análise de série temporal interrompida

ABSTRACT Objective: To evaluate the seasonality of acute bronchiolitis in Brazil during the 2020-2022 season and compare it with the previous seasons. Methods: Data from the incidence of hospitalizations due to acute bronchiolitis in infants <1 year of age were obtained from the Department of Informatics of the Brazilian Public Health database for the period between 2016 and 2022. These data were also analyzed by macro-regions of Brazil (North, Northeast, Southeast, South, and Midwest). To describe seasonal and trend characteristics over time, we used the Seasonal Autoregressive Integrated Moving Averages Model. Results: Compared to the pre-COVID-19 period, the incidence of hospitalizations related to acute bronchiolitis decreased by 97% during non-pharmacological interventions (March 2020 - August 2021) but increased by 95% after non-pharmacological interventions relaxation (September 2021 - December 2022), resulting in a 16% overall increase. During the pre-COVID-19 period, hospitalizations for acute bronchiolitis followed a seasonal pattern, which was disrupted in 2020-2021 but recovered in 2022, with a peak occurring in May, approximately 4% higher than the pre-COVID-19 peak. Conclusions: This study underscores the significant influence of COVID-19 interventions on acute bronchiolitis hospitalizations in Brazil. The restoration of a seasonal pattern in 2022 highlights the interplay between public health measures and respiratory illness dynamics in young children.

RESUMO Objetivo: Avaliar a sazonalidade da bronquiolite aguda no Brasil durante a temporada 2020-2022 e compará-la com a das temporadas anteriores. Métodos: Os dados de incidência de internações por bronquiolite aguda em lactentes <1 ano de idade foram obtidos do Departamento de Informática da base de dados da Saúde Pública Brasileira para o período entre 2016 e 2022. Esses dados também foram analisados por macrorregiões do Brasil (Norte, Nordeste, Sudeste, Sul e Centro-Oeste). Para descrever características sazonais e de tendência ao longo do tempo, utilizamos o Modelo de Médias Móveis Integradas Autorregressivas Sazonais. Resultados: Em comparação com o período pré-COVID-19, a incidência de hospitalizações relacionadas com bronquiolite aguda diminuiu 97% durante as intervenções não farmacológicas (março de 2020 - agosto de 2021), mas aumentou 95% após a flexibilização das intervenções não farmacológicas (setembro de 2021 - dezembro de 2022), resultando no aumento geral de 16%. Durante o período pré-COVID-19, as hospitalizações por bronquiolite aguda seguiram um padrão sazonal, que foi interrompido em 2020-2021, mas recuperaram-se em 2022, com um pico ocorrido em maio, aproximadamente 4% superior ao pico pré-COVID-19. Conclusões: Este estudo ressalta a influência significativa das intervenções contra a COVID-19 nas hospitalizações por bronquiolite aguda no Brasil. A restauração de um padrão sazonal em 2022 sublinha a interação entre as medidas de saúde pública e a dinâmica das doenças respiratórias em crianças pequenas.

Nontuberculous mycobacterial pulmonary disease presenting as bronchiolitis pattern on CT without cavity or bronchiectasis.

BACKGROUND: This study aimed to investigate the radiological changes in patients with nontuberculous mycobacterial pulmonary disease (NTM-PD) having bronchiolitis patterns on computed tomography (CT). METHODS: We retrospectively reviewed the final diagnosis and radiologic changes of patients suspected of having NTM-PD without cavity or bronchiectasis on CT image, between January 1, 2005 and March 31, 2021. NTM-PD was diagnosed based on the American Thoracic Society and Infectious Diseases Society of America criteria. The initial and final CT findings (bronchiectasis, cellular bronchiolitis, cavity formation, nodules, and consolidation) were compared between patients diagnosed with and without NTM-PD. RESULTS: This study included 96 patients and 515 CT images. The median CT follow-up duration was 1510.5 (interquartile range: 862.2-3005) days. NTM-PD was recognized in 43 patients. The clinical variables were not significantly different between patients with and without NTM-PD, except for underlying chronic airway disease (P < 0.001). Nodule and consolidation were more frequently observed on the initial CT scans of patients with NTM-PD compared with those without (P < 0.05). On the final follow-up CT scan, bronchiectasis (P < 0.001), cavity (P < 0.05), nodule (P < 0.05), and consolidation (P < 0.05) were more frequently observed in patients with NTM-PD. Among the 43 patients with NTM-PD, 30 showed a radiological progression on CT, with bronchiectasis (n = 22) being the most common finding. The incidence of bronchiectasis increased over time. CONCLUSION: The bronchiolitis pattern on CT images of patients with NTM-PD showed frequent radiological progression during the follow-up period.

Parental knowledge about respiratory syncytial virus and attitudes toward infant immunization with monoclonal antibodies in France.

BACKGROUND AND AIM: Respiratory syncytial virus (RSV) is a leading cause of hospitalization of infants with respiratory infections. A new immunization using monoclonal antibodies (mAbs) may offer protection against RSV infections. A study was conducted across eight countries to gain insight into parental awareness of RSV, their sources of child health information, and attitudes toward infant immunization against RSV using mAbs. This paper presents the findings from France. METHODS: In 2021, a survey was conducted in eight countries among expecting and current parents with children younger than 24 months of age. Eligible respondents included parents who were open to childhood immunizations, i.e., they had given or planned to give their children "all," "most," or "some" immunizations. RESULTS: In France, the survey respondents had high adoption rates for childhood immunizations. Key drivers behind these high rates were the desire to protect their children from severe diseases and adherence to mandatory immunizations, whereas concerns about safety were the main barriers. While general practitioners and pediatricians were key sources of advice on child health, many parents also requested information about immunizations from health authorities and nurses. Sources of advice varied with parental age, gender, educational level, and income. The majority of parents had no knowledge about mAbs or passive immunization, and the overall awareness of RSV was low. When informed about RSV and mAbs, most parents held neutral to positive attitudes toward nirsevimab for their infants if recommended by a healthcare professional and/or included in the immunization program. These findings were further confirmed by the 60 %-80 % uptake rates of nirsevimab following the introduction in September 2023.

Characteristics and predictors of outcome in children with severe acute bronchiolitis: A 10-yearexperience.

BACKGROUND: Severe acute bronchiolitis (SAB) can be life-threatening for infants and may be responsible for the congestion of intensive care units (ICU) during epidemics. We aimed to study the clinical and paraclinical characteristics of patients with SAB requiring a transfer to the ICU in order to examine their outcomes and to identify the predictors of a stay of ≥7 days and/or death. METHODS: This was a cross-sectional retrospective study including infants aged ≤12 months transferred to the ICU for their first episode of SAB between 1 January 2010 and 31 December 2019. RESULTS: We collected data on 380 patients with a median age of 1.75 months. They had a history of prematurity (20.53 %), low birth weight (18.68 %), parental atopy (12.89 %), and comorbidity (7.37 %, mainly congenital heart disease [5 %]). The leading cause of transfer was hypoxemia and increased oxygen requirements (49.73 %). The patients required mechanical ventilation (MV) in 63.42 % of the cases and noninvasive ventilation (NIV) in 67.63 %. NIV has supplanted MV over the years. Its use has increased from 40.4 % in 2010 to 96 % in 2019 compared with 83.84 % and 42 % for MV. A total of 14 (3.68 %) patients died. The independent predictors of a stay of ≥7 days and/or death were young age ≤2 months (p = 0.002), failure to thrive (p = 0.006), apnea (p = 0.045), dehydration (p = 0.018), the presence of biological inflammatory reaction (p = 0.002), isolation of respiratory syncytial virus (p < 0.001), and bacterial coinfection (p = 0.013).NIV was a protective factor (p < 0.001). A severity score ranging from 0 to 17 was established with an optimal cut-off value of 5 points. CONCLUSION: Specific caution is needed in patients with these severity predictors. The generalization ofNIV in general pediatrics departments would improve SAB management and reduce transfers to the ICU.

Asthma and health-related quality of life at 16-20 years of age in a prospectively followed post-bronchiolitis cohort.

The aim was to evaluate asthma and health-related quality of life (HRQoL) outcomes in adolescents, after hospital-treated bronchiolitis experienced in less than 6 months of age. A prospective cohort study started in 2001-2004 and followed up 166 children hospitalised for bronchiolitis in early infancy. At 16-20 years of age, 76 cases and 41 population-based controls without a history of bronchiolitis participated in the current study. Clinical asthma, presumptive symptoms and HRQoL data were collected with a structured questionnaire and the St. Georges Respiratory Questionnaire (SGRQ). Flow-volume spirometry was measured before and after bronchodilator administration. Asthma was present in 21.1% of cases in the post-bronchiolitis cohort compared to 9.8% in the control group (p = 0.21). Also, 35.5% of cases and 19.5% of controls reported dyspnea during the last 12 months (p = 0.04). In addition, total SGRQ scores were higher in the bronchiolitis group (4.26) than in the control group (1.67, p < 0.001) referring to a reduced health-related quality of life. CONCLUSION: Viral bronchiolitis in early infancy was associated with increased respiratory symptoms and lower health-related quality of life at age 16-20 years. WHAT IS KNOWN: • The prevalence of asthma at the school age and adolescence is increased after hospitalisation required bronchiolitis in infancy compared to those without hospitalisation due to bronchiolitis. WHAT IS NEW: • Viral bronchiolitis requiring hospitalisation in early infancy was associated with increased respiratory symptoms, such as dyspnoea, and lower health-related quality of life at age 16-20 years in a prospectively followed post-bronchiolitis cohort.

Prognostic value of serum total IgE and FeNO levels in children with atopic constitution bronchiolitis.

Bronchiolitis is a significant factor contributing to bronchial asthma in infants and young children. After treatment, recurrent wheezing symptoms often occur, especially in children with atopic constitution, who tend to have more severe conditions and poorer prognosis. Therefore, exploring the prognostic value of total serum immunoglobulin E (tIgE) and fractional exhaled nitric oxide (FeNO) levels in children with atopic constitution who suffer from bronchiolitis is of great significance. A total of 260 children with bronchiolitis admitted to our hospital from October 2020 to June 2022 were regarded as the research subjects with prospective study, according to whether the children had atopic constitution, they were grouped into non atopic constitution group (n = 156) and atopic constitution group (n = 104); after 6 months of treatment, children with atopic constitution were grouped into a good prognosis group (n = 58) and a poor prognosis group (n = 46) based on their prognosis; in addition, 260 healthy children who underwent physical examination and had clinical data consistent with those of children with bronchiolitis were regarded as the reference group. The serum tIgE and FeNO levels of each group were compared; multivariate Logistic regression was applied to analyze the prognostic factors of children with atopic constitution bronchiolitis; ROC curve was applied to analyze the predictive value of tIgE and FeNO levels after treatment for the prognosis of children with atopic constitution bronchiolitis. The tIgE levels in the control group, non-atopic group, and atopic group [(123.54 ± 29.62) IU/mL, (245.71 ± 30.59) IU/mL, (316.46 ± 31.78) IU/mL, respectively] increased sequentially, with statistically significant differences (F = 1766.954, P = 0.000). The FeNO levels in the control group, non-atopic group, and atopic group [(8.36 ± 3.57) ppb, (15.28 ± 3.69) ppb, (19.84 ± 3.58) ppb, respectively] also increased sequentially, with statistically significant differences (F = 765.622, P = 0.000). The tIgE, FeNO, proportion of patients with asthma family history, and proportion of patients with allergic family history in the poor prognosis group were obviously higher than those in the good prognosis group (P < 0.05). Multivariate Logistic regression analysis showed that family history of asthma, family history of allergies, tIgE, and FeNO were influencing factors for the prognosis of children with atopic bronchiolitis (P < 0.05). The AUC of the combination of tIgE and FeNO in predicting the prognosis of children with atopic constitutional bronchiolitis was 0.910, with a sensitivity of 78.26% and a specificity of 93.10%, which was superior to the independent prediction of tIgE and FeNO (Zcombined detection-tIgE = 2.442, Zcombined detection-FeNO = 3.080, P = 0.015, 0.002). The levels of tIgE and FeNO in children with atopic constitution bronchiolitis are obviously increased, and the combination of the two has high predictive value for the prognosis of atopic constitution bronchiolitis.

Viral respiratory infections requiring hospitalization in early childhood related to subsequent asthma onset and exacerbation risks.

Viral lower respiratory tract infections (LRTIs), including rhinovirus and respiratory syncytial virus during early childhood, have been linked to subsequent asthma. However, the impact of other respiratory viruses remains unclear. We analyzed nationwide Korean data from January 1, 2008, to December 31, 2018, utilizing the national health insurance database. Our study focused on 19 169 meticulously selected children exposed to severe respiratory infections requiring hospitalization with documented viral pathogens, matched with 191 690 unexposed children at a ratio of 1:10 using incidence density sampling. Our findings demonstrate that asthma exacerbation rates were higher among the exposed cohort than the unexposed cohort over a mean follow-up of 7.8 years. We observed elevated risks of asthma exacerbation and newly developed asthma compared to the unexposed cohort. Hospitalization due to rhinovirus, respiratory syncytial virus, influenza, metapneumovirus, and adenovirus was related to increased asthma exacerbations. Notably, we found a stronger association in cases of multiple LRTI hospitalizations. In conclusion, our study shows that early childhood respiratory viral infections are related to subsequent asthma exacerbations and new asthma diagnoses.

Diffuse Cystic Lung Disease: A Clinical Guide to Recognition and Management.

TOPIC IMPORTANCE: Diffuse cystic lung diseases (DCLDs) represent a group of pathophysiologically heterogeneous entities that share a common radiological phenotype of multiple thin-walled pulmonary cysts. DCLDs differ from the typical fibroinflammatory interstitial lung diseases in their epidemiology, clinical presentation, molecular pathogenesis, and therapeutic approaches, making them worthy of a distinct classification. The importance of timely and accurate identification of DCLDs is heightened by the impact on patient management including recent discoveries of targeted therapeutic approaches for some disorders. REVIEW FINDINGS: This article offers a practical framework for evaluating patients with DCLD indicating the most appropriate and current diagnostic and management approaches. We focus on the DCLDs that are most likely to be encountered by practicing pulmonologists: lymphangioleiomyomatosis, pulmonary Langerhans cell histiocytosis, Birt-Hogg-Dubé syndrome, and lymphoid interstitial pneumonia. Chest computed tomography is the most informative non-invasive diagnostic modality to identify DCLDs. Thereafter, instituting a structured approach to high-yield associated factors such as medical, social and family history, as well as renal and dermatological findings increases the likelihood of identifying DCLDs and achieving a diagnosis. SUMMARY: While the individual diseases that comprise the DCLD family are rare, taken together DCLDs can be encountered more frequently in clinical practice than commonly perceived. An increased eagerness among general pulmonary physicians to recognise these entities, coupled with a practical and systematic clinical approach to examinations and investigations is required to improve case finding, allow earlier intervention, and reduce morbidity and mortality.

Burden of respiratory syncytial virus (RSV) infection in Germany: a systematic review.

BACKGROUND: Respiratory syncytial virus (RSV) is a major cause of acute lower respiratory infection and hospitalizations among infants, young children, and the elderly. This systematic literature review aimed to summarize the epidemiological and economic burden estimates of RSV infection at any age in Germany. METHODS: We conducted a systematic literature search to identify full-text articles published from 2003 to 2023 and reporting data on the epidemiological or economic burden of RSV in Germany. Based on pre-specified eligibility criteria, data on incidence, rates of hospital and intensive care unit (ICU) admission, clinical manifestation, underlying conditions, seasonality, health care resource use and costs were extracted. RESULTS: After screening 315 full-text articles, we included 42 articles in the review. The characteristics of the included studies were heterogenous regarding study population, setting, age groups and RSV-related outcome measures. The most frequently reported epidemiological outcome measures were RSV detection rate (n = 33), followed by clinical manifestation (n = 19), seasonality (n = 18), and underlying conditions of RSV infection (n = 13). RSV detection rates were reported across heterogenous study populations, ranging from 5.2 to 55.4% in pediatric inpatient cases and from 2.9 to 14% in adult inpatient cases. All articles that reported RSV detection rates across several age groups demonstrated the highest burden in infants and young children. Few articles reported RSV-related outcome measures distinctively for the outpatient setting. Health care resource use, such as hospital length of stay, ICU admission rate and treatment of patients with RSV infection were described in 23 articles, of which only one study quantified associated costs from 1999 to 2003 for children ≤ 3 years. In-hospital ICU admission rates varied between 3.6 and 45%, depending on population characteristics as age and underlying conditions. CONCLUSIONS: This systematic review revealed that RSV imposes substantial disease burden in infants, young children, and the elderly in Germany, whereby infants are particularly affected. To date, there has been limited exploration of the impact of RSV infection on healthy children or the elderly in Germany. Given their notably high reported burden in studies, the medical and economic RSV burden in these groups should move more into focus.

Using the near real-time effective reproduction number rt as an early-warning tool for seasonal bronchiolitis and influenza-like illness epidemics.

BACKGROUND: Yearly bronchiolitis and influenza-like illness epidemics in France often involve high morbidity and mortality, which severely impacts healthcare. Epidemics are declared by the French National Institute of Public Health based on syndromic surveillance of primary care and emergency departments (ED), using statistics-based alarms. Although the effective reproduction number (Rt) is used to monitor the dynamics of epidemics, it has never been used as an early warning tool for bronchiolitis or influenza-like illness epidemics in France.We assessed whether Rt is useful for detecting seasonal epidemics by comparing it to the tool currently used (MASS) by epidemiologists to declare epidemic phases. METHODS: We used anonymized ED syndromic data from the Île-de-France region in France from 2010 to 2022. We estimated Rt and compared the indication of accelerated transmission (Rt >1) to the MASS epidemic alarm time points. We computed the difference between those two time points, time to epidemic peak, and the daily cases documented at first indication and peak. RESULTS: Rt provided alarms for influenza-like illness and bronchiolitis epidemics that were, respectively, 6 days (IQR[4;8]) and 64 days (IQR[52;80]) - in median - earlier than the alarms provided by MASS. CONCLUSION: Rt detected earlier signals of bronchiolitis and influenza-like illness epidemics. Using this early-warning indicator in combination with others to declare an annual epidemic could provide opportunities to improve healthcare system readiness.

Effectiveness of nirsevimab against RSV-bronchiolitis in paediatric ambulatory care: a test-negative case-control study.

Background: Respiratory syncytial virus (RSV) is the leading cause of lower-respiratory-tract infection in children. Nirsevimab, a monoclonal antibody against RSV, was implemented in a few countries in September 2023. However, its post-license effectiveness in ambulatory care settings is unknown. We aimed to assess the effectiveness of nirsevimab against RSV-bronchiolitis in outpatients aged <12 months. Methods: We conducted a test-negative case-control study based on a national ambulatory surveillance system. We included all infants aged <12 months who had bronchiolitis and results of an RSV rapid antigen test performed, visiting a network of 107 ambulatory paediatricians from September 15, 2023, to February 1, 2024. Case patients were infants with bronchiolitis and a rapid antigen test positive for RSV. Control patients were infants with bronchiolitis and a rapid antigen test negative for RSV. Effectiveness was assessed by a logistic regression model adjusted for potential confounders. A range of sensitivity analyses were conducted to assess the robustness of the findings. Findings: We included 883 outpatients who had bronchiolitis and results of an RSV rapid antigen test (453 were case patients, and 430 were control patients). Overall, 62/453 (13.7%) case patients and 177/430 (41.2%) control patients had been previously immunised for nirsevimab. The adjusted effectiveness of nirsevimab against RSV-bronchiolitis was 79.7% (95% CI 67.7-87.3). Sensitivity analyses gave similar results. Interpretation: This post-license study indicates that nirsevimab was effective in preventing RSV-bronchiolitis in ambulatory care settings. Funding: The study was supported by Association Clinique et Thérapeutique Infantile du Val de Marne (ACTIV), French Pediatrician Ambulatory Association (AFPA) and unrestricted grants from GSK, MSD, Pfizer and Sanofi.

A 62-Year-Old Woman With Cough, Dyspnea, and Diffuse Lung Nodules.

CASE PRESENTATION: A 62-year-old woman came to our hospital with worsening cough and dyspnea over the preceding week, during which time she had been treated with azithromycin and prednisone for suspected pneumonia. She had no fever, chills, or sweats, but her cough had become productive of clear to blood-tinged phlegm during the interval. Medical history was significant for insulin-dependent diabetes mellitus and OSA. She had quit smoking 44 years earlier and had no history of lung disease. She was a bank teller residing in southeastern Minnesota and described no relevant inhalational or environmental exposures, drug use, aspiration, or travels preceding her illness.

Risk factors for bronchiolitis obliterans complicating adenovirus pneumonia in children: a meta-analysis.

Objective: To preliminarily explore the risk factors for post-infectious bronchiolitis obliterans (PIBO) complicating adenovirus pneumonia (ADVP) in children through a meta-analysis. Methods: A systematic search was conducted on three English-language databases (PubMed, Web of Science and The National Library of Medicine) and two Chinese-language databases (China National Knowledge Infrastructure and the Wanfang Database) between database inception and 1 January 2023. Data analysis was conducted using Stata 15.1 software. Results: A total of 10 articles, reporting 14 risk factors, were included in the analysis, with 8 risk factors taken into consideration. Through the meta-analysis, 5 risk factors were identified for PIBO complicating ADVP in paediatric patients: hypoxaemia [odds ratio (OR) = 9.37, 95% CI: 4.22, 20.77, p < 0.001], persistent wheezing (OR = 4.65, 95% CI: 2.20, 9.82, p < 0.001), mechanical ventilation (OR = 3.87, 95% CI: 2.37, 6.33, p < 0.001), length of hospital stay (LoHS) (OR = 1.25, 95% CI: 1.09, 1.43, p < 0.001) and fever duration (OR = 1.08, 95% CI: 1.02, 1.14, p = 0.009). Conclusion: Existing evidence suggests that hypoxaemia, persistent wheezing, mechanical ventilation, LoHS and fever duration are risk factors for PIBO complicating ADVP in children. These findings underscore the need for enhanced assessment and management in clinical practice. This study may provide such a clinical prediction model from the identified 5 risk factors for PIBO and offer valuable insights for preventing bronchiolitis obliterans in children with ADVP.

The Use of Evaluation Methods for Physiotherapy Treatment in Infants With Bronchiolitis-a Survey Study.

AIMS: The aim of this study was to identify and describe methods that physiotherapists use to evaluate the immediate effects of their interventions for infants in hospital with acute respiratory tract infections. METHODS: We constructed an anonymous digital survey to physiotherapists working with infants aged 0-24 months in Sweden. The survey was distributed by e-mail and posted on web pages for seven weeks, which included a reminder. RESULTS: Replies were obtained from 88 respondents, and 52 completed surveys remained to be analyzed. All 21 counties in Sweden were represented. The most prevalent answer options were as follows: more productive/increased or decreased cough (73%), increased oxygen saturation (35%), changed secretion sounds (33%), reduced work of breathing (20%), and parental report (16%). CONCLUSIONS: The physiotherapists reported to use diverse methods for evaluation of their interventions. However, to a large degree they used subjective measures, which depend on the individual clinician's assessment and interpretation. The evaluation methods vary in psychometric properties and robustness. This study identifies the need for consensus about valid, reliable, and clinically relevant evaluation methods for this patient group.

Post viral bronchiolitis obliterans in children: A rare and potentially devastating disease.

Post infectious bronchiolitis obliterans (PIBO) is a rare but severe disease in children. Several respiratory pathogens are incriminated but adenovirus is still the most represented. Risk factors are well described: the male gender, hypoxemia at diagnosis and required mechanical ventilation. No risk factor is linked to the newborn period. The clinical spectrum of PIBO is broad, ranging from asymptomatic patients with fixed airflow obstruction to severe respiratory insufficiency requiring continuous oxygen supplementation. Diagnosis includes a combination of a clinical history, absence of reversible airflow obstructions and ground glass and gas trapping on high resolution computed tomography. PIBO is primarily a neutrophilic pathology of small bronchioles characterized by high levels of pro-inflammatory cytokines leading to tissue remodeling and fibrosis of the small airways. The difficulty is to discriminate between the host's normal response, an exaggerated inflammatory response and the potential iatrogenic consequences of the initial infection treatment, particularly prolonged mechanical ventilation. Damage to the respiratory epithelium with a possible link to viral infections are considered as potential mechanisms of PIBO. No specific management exists. Much remains to be done in this field to clarify the underlying mechanisms, identify biomarkers, and develop clear monitoring pathways and treatment protocols.

Pediatric Respiratory Infections After the COVID-19 Pandemic: A Single-Center Experience.

Background Pediatric respiratory infections, mainly bronchiolitis, are a substantial clinical burden. The most common etiology is respiratory syncytial virus (RSV). Other viruses include human rhinovirus, human metapneumovirus, influenza, adenovirus, coronavirus, and parainfluenza viruses. Objective We aimed to study the epidemiology and clinical characteristics of children with confirmed viral bronchiolitis and flu after the COVID-19 pandemic season and compare the behavior of each virus. Methods This retrospective observation study was done over seven months, from October 2022 to April 2023. All children (0-14) were included in the study if they met the clinical diagnosis of bronchiolitis or flu. Viral etiology is confirmed by PCR, using the respiratory panel available in our center which included the detection of four viruses: COVID-19, RSV, influenza A, and B. Clinical data, lab results, and X-rays were collected and correlated with each viral infection for all admitted patients. Results We recruited 237 children with bronchiolitis and flu symptoms from October 2022 to April 2023. The peak of infections (41%) was in November. Seasonal variations for each virus showed distinct patterns across the year. RSV peaked at the beginning of the season, gradually declining after that. In contrast, influenza A and B maintained a relatively consistent presence throughout the season. Meanwhile, COVID-19 reached its peak during March and April. One hundred forty-four (60%) of the patients were under two years of age. RSV was predominant in 150 patients (63.3%). COVID-19 was only detected in 25 patients (10%), whereas influenza A and B were equally isolated in 31 (13%) patients each. Fifty-one children (21%) were initially sick and required pediatric intensive care unit (PICU) admission, with no deaths reported. Notably, COVID-19 had a milder disease course, a shorter length of stay (LOS) in the hospital (two days) and a shorter duration of illness (five days) compared to other viruses. RSV infection was linked to more profound hypoxia and more sick children with more extended hospital stays. Conclusion Our study showed that, following the pandemic and the release of lockdown measures, there was another peak of upper respiratory tract infections (URTI) and flu, which was more aggressive, primarily due to other viruses, especially RSV. This resurgence was associated with more severe respiratory symptoms and an increased need for hospitalization. Notably, children with COVID-19 were in better condition compared to those with RSV.

Clinical impact of airflow obstruction after allogeneic hematopoietic stem cell transplantation.

Criteria for airflow obstruction (AFO) at one year after allogeneic hematopoietic stem cell transplantation (allo-HSCT) in pulmonary function tests (PFTs) are more stringent than the bronchiolitis obliterans syndrome (BOS) criteria of the National Institutes of Health. This single-center, retrospective cohort study evaluated the clinical impact of the AFO criteria at any time after transplantation. In 132 patients who underwent allo-HSCT from 2006 to 2016, the 2-year cumulative incidence of AFO was 35.0%, and the median time to diagnosis of AFO was 101 days after transplantation (range 35-716 days). Overall chronic graft-versus-host disease (cGVHD) incidence was significantly higher in patients with AFO than in those without AFO (80.4% vs. 47.7%, P < 0.01); notably, 37.0% of patients with AFO developed cGVHD after AFO diagnosis. AFO patients developed BOS with a 5-year cumulative incidence of 49.1% after AFO onset. The 5-year cumulative incidence of non-relapse mortality in the AFO group was higher than that in the non-AFO group (24.7% vs. 7.1%, P < 0.01). These results suggest that closely monitoring PFTs within two years after allo-HSCT, regardless of cGVHD status, is important for early detection of AFO and prevention of progression to BOS. (192words).

Clinical-Ultrasound Model to Predict the Clinical Course in Bronchiolitis.

BACKGROUND: The aim of the present study was to develop a clinical-ultrasound model for early detection of hospital admission, pediatric intensive care unit (PICU) admission, and oxygen requirement in children diagnosed with acute bronchiolitis (AB). Furthermore, the prognostic ability of models including sonographic data from antero-lateral, lateral-posterior, and posterior areas (eight zones) vs. antero-lateral and lateral-posterior areas (six zones) vs. only antero-lateral areas (four zones) was analyzed. METHODS: A prospective study was conducted on infants under 12 months with AB. A lung ultrasound (LUS) was performed within 24 h of hospital care and analyzed using the Lung Ultrasound Combined Score (LUCS) based on the ultrasound patterns and their extent. Regression models combining LUCS (using eight, six, or four lung areas) with age and clinical scale were created. RESULTS: A total of 90 patients were included (62 admitted to the ward, 15 to PICU), with a median age of 3.7 months. Clinical-ultrasound models with eight and six lung zones predicted hospital admission (AUC 0.89), need for oxygen therapy (AUC 0.88), and its duration (40% explanatory capacity). Models using four lung areas had lower prognostic yield. No model predicted PICU admission needs or duration. CONCLUSIONS: The ultrasound pattern and its extension combined with clinical information may be useful to predict hospital admission and oxygen requirement.

The Impact of Donor-Recipient Human Leukocyte Antigen Matching on Bronchiolitis Obliterans-Free Survival Among Lung Transplant Recipients With Connective Tissue Diseases.

BACKGROUND: The development of connective tissue disease-associated lung diseases (CTD-LD) occurs in association with specific human leukocyte antigens (HLA). For CTD-LD patients who require lung transplant, it is unknown whether utilization of donor organs expressing these same HLA impacts posttransplant outcomes. METHODS: Using the Scientific Registry of Transplant Recipients, we assessed whether CTD-LD lung transplant recipients in the United States have worse bronchiolitis obliterans (BOS)-free survival based on the degree of donor HLA matching. This included overall degree of donor-recipient HLA matching, donor-recipient matching at DR loci, and recipient matching with specific donor HLA antigens associated with the development of pulmonary disease in their condition. RESULTS: Among 1413 patients with CTD-ILD, highly HLA-matched donor-recipients did not have worse adjusted survival (hazard ratio [HR] = 0.93, 95% confidence interval [CI] = 0.58-1.51, p = 0.77). Recipients who were fully matched at HLA DR did not have worse survival (HR = 0.82, 95% CI = 0.56-1.19, p = 0.29). Finally, among individual CTD-LD, including rheumatoid arthritis, systemic sclerosis, the idiopathic inflammatory myopathies, and systemic lupus erythematous, transplant with a donor expressing HLA antigens associated with lung manifestations in these conditions was not associated with worse BOS-free survival. CONCLUSIONS: Among transplant recipients with CTD-LD, HLA donor-recipient matching, including at the DR loci, does not result in worse BOS-free survival. Based on these findings, there is no reason to treat these as unacceptable antigens when considering donor offers for CTD-LD candidates.