Sleep and quality of life characteristics in a pediatric population with chronic obstructive respiratory diseases.

PURPOSE: To describe sleep and quality of life of pediatric patients with chronic obstructive respiratory diseases and to ascertain whether or not sleep quality correlates with quality of life in this population. METHODS: Participants aged 5 to 18 years with cystic fibrosis (CF), severe asthma, or postinfectious bronchiolitis obliterans (PIBO) receiving regular follow-up at a pediatric respiratory medicine center were recruited. Two questionnaires were used: the Brazilian version of the Sleep Disturbance Scale for Children (SDSC) and the Pediatric Quality of Life Inventory (Peds-QL). RESULTS: A total of 46 individuals were included: 30 with CF, 9 with severe asthma, and 7 with PIBO. Almost two-thirds of the patients and their parents or guardians scored at least 39 points on the SDSC, suggesting poor sleep quality. Significantly higher overall median scores were observed in those with severe asthma. Patients and their parents or guardians scored a median of 77 and 80 points respectively on the Peds-QL, with parents of patients with CF scoring higher than any other group. There was a moderate inverse correlation between sleep disorders and quality of life (r = - 0.532 for patients and r = - 0.606 for parents; p < 0.001). CONCLUSION: Children and adolescents with chronic obstructive respiratory diseases experience impairment in their sleep quality and quality of life. Sleep disorders and quality of life have a moderate negative correlation.

Early Impact of Social Distancing in Response to Coronavirus Disease 2019 on Hospitalizations for Acute Bronchiolitis in Infants in Brazil.

BACKGROUND: Interventions to tackle the coronavirus disease 2019 (COVID-19) pandemic may affect the burden of other respiratory diseases. Considering the repercussions of these unique social experiences to infant health, this study aims to assess the early impact of social distancing due to the COVID-19 pandemic in hospital admissions for acute bronchiolitis. METHODS: Data from hospitalizations of 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 2020. These data were also analyzed by macroregions of Brazil (North, Northeast, Southeast, South, and Midwest). To evaluate the effect of social distancing strategy on the incidence of acute bronchiolitis, the absolute and relative reductions were calculated by analyzing the yearly subsets of 2016 vs 2020, 2017 vs 2020, 2018 vs 2020, and 2019 vs 2020. RESULTS: There was a significant reduction in all comparisons, ranging from -78% (incidence rate ratio [IRR], 0.22 [95% confidence interval {CI}, .20-.24]) in 2016 vs 2020 to -85% (IRR, 0.15 [95% CI, .13-.16]) in 2019 vs 2020, for the data from Brazil. For analyses by macroregions, the reduction varied from -58% (IRR, 0.41 [95% CI, .37-.45]) in the Midwest in 2016 vs 2020 to -93% (IRR, 0.07 [95% CI, .06-.08]) in the South in 2019 vs 2020. CONCLUSIONS: There was a significant reduction in hospitalization for acute bronchiolitis in children <1 year old in Brazil, on the order of >70% for most analysis. Our data suggest an important impact of social distancing on reducing the transmission of viruses related to acute bronchiolitis. Such knowledge may guide strategies for prevention of viral spread.

Frequency of CFTR variants in southern Brazil and indication for modulators therapy in patients with cystic fibrosis.

This is a descriptive cross-sectional study that aims to determine the distribution of the CFTR causing variant in a group of patients at a cystic fibrosis (CF) center in southern Brazil, as well as to describe causing variants that are treatable with mutation-specific drugs. Ninety-two patients from a CF reference center were assessed in this research, all of them with a clinical diagnosis of CF and both alleles identified with pathogenic variants. The most prevalent causing variants were F508del, R1162X, G542X, and N1303K. As for patients with a mutation-specific drug indication, 69.6 % were candidates for the use of Elexacaftor/Tezacaftor/Ivacaftor (Trikafta®), 44.6 % for the use of Tezacaftor/Ivacaftor (Symdeko®), and 35.9 % for the use of Lumacaftor/Ivacaftor (Orkambi®). For the use of Ivacaftor (Kalydeco®), only two patients (2.2 %) were candidates following the Brazilian agency approval. According to the FDA, 10 patients would be candidates for Ivacaftor (10.9 %). Causing variants of classes I and II, which are related to a major severity of the illness, were identified in 135 of 184 alleles (73.3 %). In this study, more than 2/3 of the patients were candidates for the use of CFTR modulators therapy.

Novel frameshift variant of the CFTR gene: S511Lfs*2 from phenotype to molecular predictions.

Cystic fibrosis (CF) is a genetic disease caused by variants in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. There are over 2,000 different pathogenic and non-pathogenic variants described in association with a broad clinical heterogeneity. In this work, we identified a novel variant S511Lfs*2 in CFTR gene that has not been reported in patients with CF. The patient was a female genotyped with c.1000C>T (legacy name: R334W) variant (pathogenic, CF-causing) and the novel variant (S511Lfs*2). We verified the amino acid sequence, the protein structure, and predicted the pathogenicity employing computational analysis. Our findings showed that S511Lfs*2 is a frameshift variant and suggest that it is associated with severe CF phenotype, as it leads to a lack of CFTR protein synthesis, and consequently the loss of its functional activity.

Burden of asthma among inner-city children from Southern Brazil.

OBJECTIVE: To assess the impact of asthma in a population of inner-city Brazilian children. METHODS: In a cross-sectional study, we selected children with asthma and healthy controls from public schools (8-16 years) from a capital city of Southern Brazil. Divided into three phases, questionnaires were administered, assessing lung function, body mass index and allergic sensitization. RESULTS: From 2500 children initially included in the study (48.4% males; mean age of 11.42 ± 2.32 years), asthma prevalence was detected in 28.6% (715/2500). The disease was not controlled in 42.7% (305/715) of the children, with 7.6% of hospitalization rate. School absenteeism (at least one day of missing school because of asthma) and sedentary behavior were high (57.1 and 67.2%, respectively), with 47.9% of subjects requiring oral steroids in the previous year, and physical well-being significantly lower than controls, directly interfering with quality of life, and therefore in the daily activities of these students. Moreover, 38% of the parents admitted to being non-adherent to treatment with their children and 31.1 and 53.6%, respectively, believed that rescue medication and exercise might be harmful. CONCLUSIONS: The burden of asthma in Brazilian children seems to be substantial. New international guidelines with a special focus in developing countries settings, with more pragmatic approaches, should be a priority for discussion and implementation actions.

IL10 polymorphisms influence neonatal immune responses, atopic dermatitis, and wheeze at age 3 years.

BACKGROUND: IL10 encodes for IL-10, an important anti-inflammatory cytokine with pleiotropic effects. It is crucial for development of immune tolerance, downregulates expression of TH1 cytokines, and is relevant for T-cell regulation. Several IL10 single nucleotide polymorphisms (SNPs) were associated with inflammatory diseases, such as atopic diseases, which might have their onset during early immune maturation. OBJECTIVE: We hypothesized that IL10 SNPs are associated with decreased regulatory T (Treg) cell numbers, TH2-skewed immune responses, and decreased IFN-γ levels in cord blood parallel with increased proinflammatory markers, subsequently leading to increased atopic diseases until 3 years. METHODS: Eight genetic IL10 variants, represented by 4 linkage disequilibrium blocks (R(2) > 0.80) and 2 distal promoter SNPs, were genotyped in cord blood mononuclear cells of 200 healthy neonates. Cord blood mononuclear cells were cultured unstimulated or after stimulation with lipid A, peptidoglycan, PHA, house dust mite (Der p 1), or Der p 1 plus lipid A. mRNA expression of Treg cell-associated genes (forkhead box protein P3 [FOXP3], glucocorticoid-induced TNF receptor [GITR], lymphocyte activation gene 3 [LAG3]), TH1/TH2 cytokines, TNF-α, and GM-CSF were assessed. Atopic and respiratory outcomes (atopic dermatitis [AD] and wheeze) were assessed by means of questionnaire at age 3 years. RESULTS: Carriers of 3 IL10 SNP blocks and both distal promoter SNPs showed reduced expression of Treg cell markers, reduced IL-5 levels, proinflammatory TNF-α and GM-CSF, and partially increased IFN-γ levels. The same SNPs presented as determinant for AD, wheeze, or symptoms of AD, wheeze, or both at age 3 years. CONCLUSIONS: Polymorphisms in IL10 influenced Treg cell marker expression and TH1/TH2 and proinflammatory cytokine secretion early in life. This was relevant for further development of immune-mediated diseases, such as AD and wheeze, in early childhood.

Benzbromarone as adjuvant therapy for cystic fibrosis lung disease: a pilot clinical trial.

OBJECTIVE: Cystic fibrosis (CF) affects multiple organs, the most severe consequences being observed in the lungs. Despite significant progress in developing CF transmembrane conductance regulator-specific treatments for CF lung disease, exploring alternative CF-targeted medications seems reasonable. We sought to evaluate the potential beneficial effects of oral benzbromarone as an adjuvant therapy in CF patients with reduced lung function. METHODS: This was a prospective open-label pilot study of oral benzbromarone (100 mg/day) administered once daily for 90 days. Patients were followed at a tertiary referral center in southern Brazil. Safety was assessed by the number of reported adverse events. Secondary objectives included percent predicted FEV1 (FEV1%) and pulmonary exacerbations. RESULTS: Ten patients were enrolled. Benzbromarone was found to be safe, with no serious drug-related adverse events. Eight patients completed the study; the median relative change in FEV1% tended to increase during the treatment, showing an 8% increase from baseline at the final visit. However, a nonparametric test showed that the change was not significant (p = 0.06). Of a total of ten patients, only one experienced at least one pulmonary exacerbation during the study. CONCLUSIONS: Oral benzbromarone appears to be safe, and improved FEV1% has been observed in patients with CF. Further assessment in larger trials is warranted to elucidate whether oral benzbromarone can be a potential adjuvant therapy for CF.

Seasonality of the incidence of bronchiolitis in infants - Brazil, 2016-2022: An interrupted time-series analysis.

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.

Electronic cigarettes: "wolves in sheep's clothing".

OBJECTIVE: To provide cutting-edge information on the impact and risks of using Electronic Nicotine Delivery Systems (ENDS) by children and adolescents, based on the latest evidence published in the literature. DATA SOURCE: A comprehensive search was carried out on PubMed, using the expressions ''electronic cigarettes'' OR ''electronic nicotine delivery systems" OR "vaping" AND ''adolescent'' AND "risks" AND ''acute lung injury'. All retrieved articles had their titles and abstracts read to identify and fully read the papers reporting the most recent evidence on each subject. SUMMARY OF FINDINGS: The use of ENDS has alarmingly increased in Brazil and around the world. The possibility of customizing use, the choice of flavors and nicotine content, and the general notion that these devices are harmless when compared to conventional cigarettes are some of the factors responsible for this increase. Numerous scientific studies have proven that electronic cigarettes have serious consequences for the respiratory system, such as EVALI (E-cigarette or Vaping-Associated Lung Injury) and difficult-to-control asthma, as well as harmful effects on the neurological, cardiovascular, gastrointestinal, and immunological systems. High concentrations of nicotine make many young people addicted to this substance. In Brazil, commercialization, import, and advertising are prohibited. The viable interventions to address the use of these devices in children and adolescents are prevention and behavioral counseling. CONCLUSION: There is clear scientific evidence that these devices pose a risk to the physical and mental health of children and adolescents.

Impact of COVID-19 social distancing recommendations on pulmonary function, nutritional status, and morbidity in patients with cystic fibrosis.

OBJECTIVE: To evaluate the impact of COVID-19 social distancing recommendations on nutritional status, pulmonary function, and morbidity in patients with cystic fibrosis (CF). METHODS: A retrospective cohort study including patients older than six years with a diagnosis of CF was performed. Demographic and clinical data, anthropometric measurements, pulmonary function, days of antibiotic use, and length of hospital stay were recorded. Variables were recorded at three time points relative to the baseline for implementation of social distancing measures: T-1 (14 months before implementation), T0 (baseline), and T1 (14 months after implementation). Delta (Δ) was calculated for each period: Δ1 (pre-pandemic T0-T-1) and Δ2 (pandemic T1-T0). RESULTS: The study included 25 patients, with a mean age of 11.7±4.3 years. The mean forced expiratory volume in the first second (FEV1) was 85.6±23.6%, and body mass index (BMI) was 17.5±3.0 kg/m2. When comparing the two periods (Δ1 and Δ2), there was a significant increase in the FEV1/forced vital capacity (FVC) ratio (p=0.013) and in the forced expiratory flow between 25 and 75% of vital capacity (FEF25-75%) (p=0.037) in the pandemic period. There was also a significant reduction (p=0.005) in the use of antibiotics in the pandemic period compared with the pre-pandemic period. The Δ1 and Δ2 values did not differ significantly for BMI, FEV1, or length of hospital stay. CONCLUSIONS: COVID-19 social distancing recommendations had a positive impact (decrease) on morbidity (use of antibiotics) and small airway obstruction (FEF25-75%) in patients with CF.

Brazilian guidelines for the pharmacological treatment of the pulmonary symptoms of cystic fibrosis. Official document of the Sociedade Brasileira de Pneumologia e Tisiologia (SBPT, Brazilian Thoracic Association).

Cystic fibrosis (CF) is a genetic disease that results in dysfunction of the CF transmembrane conductance regulator (CFTR) protein, which is a chloride and bicarbonate channel expressed in the apical portion of epithelial cells of various organs. Dysfunction of that protein results in diverse clinical manifestations, primarily involving the respiratory and gastrointestinal systems, impairing quality of life and reducing life expectancy. Although CF is still an incurable pathology, the therapeutic and prognostic perspectives are now totally different and much more favorable. The purpose of these guidelines is to define evidence-based recommendations regarding the use of pharmacological agents in the treatment of the pulmonary symptoms of CF in Brazil. Questions in the Patients of interest, Intervention to be studied, Comparison of interventions, and Outcome of interest (PICO) format were employed to address aspects related to the use of modulators of this protein (ivacaftor, lumacaftor+ivacaftor, and tezacaftor+ivacaftor), use of dornase alfa, eradication therapy and chronic suppression of Pseudomonas aeruginosa, and eradication of methicillin-resistant Staphylococcus aureus and Burkholderia cepacia complex. To formulate the PICO questions, a group of Brazilian specialists was assembled and a systematic review was carried out on the themes, with meta-analysis when applicable. The results obtained were analyzed in terms of the strength of the evidence compiled, the recommendations being devised by employing the GRADE approach. We believe that these guidelines represent a major advance to be incorporated into the approach to patients with CF, mainly aiming to favor the management of the disease, and could become an auxiliary tool in the definition of public policies related to CF.

Impact of COVID-19 mitigation strategies on asthma hospitalizations in Brazil.

Background: In 2020, a unique social experience was provided by the pandemic of coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2. Interventions to tackle the pandemic may affect the burden of other respiratory diseases. Objective: This study aims to assess the impact of the COVID-19 mitigation strategies on hospitalizations for asthma in children aged between 1 and 14 years, adults aged between 20 and 59 years, and elderly older than 60 years. Methods: Data from hospital admissions for asthma were obtained from the Department of Informatics of Brazilian Public Health System database in the period between January 2016 and December 2020 and analyzed by age groups. To evaluate the effect of containment measures on the incidence of asthma and respiratory system diseases (total), the absolute reduction and relative reduction were calculated by analyzing the subsets from 2016 to 2019 versus 2020. Results: There was a significant reduction in the average incidence of hospitalizations in 2020, with numbers ranging from -59% (incidence rate ratio, 0.41 [0.37-0.45]) for age 1 to 14 years (prepandemic 1,393.2/100,000 vs pandemic 574.9/100.000), -37% (incidence rate ratio, 0.63 [0.49-0.80]) for age 20 to 59 years (prepandemic 160.2/100,000 vs pandemic 101.1/100,000), and -60% (incidence rate ratio, 0.40 [0.33-0.47]) for older than 60 years (prepandemic 460.6/100,000 vs pandemic 185.3/100,000). Conclusions: Ashtma hospitalizations decreased in 2020, especially in the pediatric group and the older group during the COVID-19 pandemic, which may be associated with the reduction in the incidence of many respiratory viral infections.

Translational Research in Cystic Fibrosis: From Bench to Beside.

Cystic fibrosis is the most common life-limiting recessive genetic disorder in Caucasian populations, characterized by the involvement of exocrine glands, causing multisystemic comorbidities. Since the first descriptions of pancreatic and pulmonary involvement in children, technological development and basic science research have allowed great advances in the diagnosis and treatment of cystic fibrosis. The great search for treatments that acted at the genetic level, despite not having found a cure for this disease, culminated in the creation of CFTR modulators, highly effective medications for certain groups of patients. However, there are still many obstacles behind the treatment of the disease to be discussed, given the wide variety of mutations and phenotypes involved and the difficulty of access that permeate these new therapies around the world.

Impact of social distancing in response to COVID-19 on hospitalizations for laryngitis, tracheitis, otitis media, and mastoiditis in children aged 0 to 9 years in Brazil.

OBJECTIVE: The objective of this study is to evaluate the impact of social distancing resulting from COVID-19 in hospitalizations for infections of the upper airways (URTI), such as acute laryngitis, tracheitis, and otitis media in children aged 0 to 9 years in Brazil, considering that they share the same forms of transmission. METHODS: Data on hospitalizations for acute airway changes and their complications in children <9 years old were obtained from the Database of the Brazilian Department of Public Health Informatics for the period 2015 to 2020. These data were also analyzed by macroregions of Brazil (North, Northeast, Southeast, South, and Midwest). The effect of the social distancing strategy on the increase of acute laryngitis, tracheitis, otitis media, and mastitis, as absolute and relative reductions, was calculated by analyzing the annual calculation of 2015-2019 vs 2020. RESULTS: All the hospitalizations compared in the Unified Health System (SUS) for laryngitis and acute tracheitis and otitis media decreased, considering all states of Brazil. The largest reduction in hospitalization reduction was in the North, with -94% in 2015-2019 vs 2020 in cases of laryngitis and acute tracheitis, and in the Midwest, with - 85% in 2015-2019 vs 2020 in cases of otitis media. CONCLUSION: Hospitalizations for laryngitis, acute tracheitis, and acute otitis media in children <9 years old decreased between March and July 2020 in Brazil, when social distancing measures were adopted due to the COVID-19 pandemic.

Association between interleukin-10 polymorphisms and CD4+CD25+FOXP3+ T cells in asthmatic children.

OBJECTIVE: The aim of this study was to evaluate the association between possible functional interleukin-10 (IL-10) polymorphisms, IL-10 expression and regulatory T cells (Tregs) frequency, and/or asthma severity in a sample of children and adolescents. METHODS: This is a nested case-control genetic association study. The study sample consisted of children and adolescents aged 8-14 from public schools. Four polymorphisms of the IL-10 gene (rs1518111, rs3024490, rs3024496, rs3024491) were genotyped in asthmatic subjects and controls using real-time PCR. Tregs cells and IL-10 were analyzed in peripheral blood mononuclear cells by flow cytometry. The severity of asthma was defined according to the Global Initiative for Asthma (GINA) guideline. RESULTS: One hundred twenty-three asthmatic subjects and fifty-eight controls participated in the study. The single nucleotide polymorphism (SNP) rs3024491 (T allele) showed association with asthma severity, presenting a higher frequency in patients in the moderate asthma group. The T allele of variant rs3024491 also showed an association with reduced IL-10 levels (p=0.01) and with increased Tregs frequency (p=0.01). The other variants did not present consistent associations. CONCLUSIONS: Our results suggest that moderate asthma is associated with a higher frequency of the T allele in the SNP rs3024491. In addition, the variant rs3024491 (TT) was associated with a reduction in IL-10 production and an increased percentage of Tregs cells, suggesting possible mechanisms that influence asthma severity.

Impact of nonpharmacological COVID-19 interventions in hospitalizations for childhood pneumonia in Brazil.

BACKGROUND AND OBJECTIVE: The knowledge about the impact of the nonpharmacological measures to control the COVID-19 pandemic can give insight into ways in which they can also be applied for other respiratory diseases. To assess the impact of containment measures of the COVID-19 pandemic on pneumonia hospitalizations in children from 0 to 14 years of age in Brazil. METHODS: Data from hospital admissions for pneumonia were obtained from the Department of Informatics of Brazilian Public Health System database in the period of 2015-2020 and analyzed by macroregions and age groups. To evaluate the effect of containment measures, on the incidence of pneumonia, the absolute reduction and relative reduction were calculated by analyzing the subsets 2015-2019 vs. 2020. RESULTS: Comparing the subsets of April-August 2015-2019 vs. April-August 2020 for Brazil (total), there was an significant reduction in the average incidence of hospitalizations, with numbers ranging from -82% [IRR 0.17 (0.14-0.21)] for <4 years (prepandemic 741.8/100,000 vs. pandemic 132.7/100.000), -83% [IRR 0.17 (0.10-0.27)] for 5-9 years (prepandemic 113.6/100,000 vs. pandemic 19.6/100.000), -77% [IRR 0.23 (0.11-0.46)] for 10-14 (prepandemic 42.0/100,000 vs. pandemic 9.8/100.000) and -82% [IRR 0.18 (0.15-0.21)] for all children ≤14 years (prepandemic 897.4/100,000 vs. pandemic 162.1/100.000). CONCLUSION: We found a significant decrease in cases of all cause pneumonia in children under 14 years and especially in the age group <9 years during the COVID-19 pandemic, which may be associated with the nonpharmacological measures applied to control the SARS-CoV-2.

Absence of detection of RSV and influenza during the COVID-19 pandemic in a Brazilian cohort: Likely role of lower transmission in the community.

BACKGROUND: Respiratory syncytial virus (RSV) and influenza are prevalent seasonal community viruses. Although not completely understood, SARS-CoV-2 may have the same means of transmission. Preventive social measures aimed at preventing SARS-CoV-2 spread could impact transmission of other respiratory viruses as well. The aim of this study is to report the detection of RSV and influenza during the period of social distancing due to COVID-19 pandemic in a heavily affected community. METHODS: Prospective study with pediatric and adult populations seeking care for COVID-19-like symptoms during the fall and winter of 2020 at two hospitals in Southern Brazil. RT-PCR tests for SARS-CoV-2, influenza A (Flu A), influenza B (Flu B) and respiratory syncytial virus (RSV) was performed for all participants. RESULTS: 1435 suspected COVID-19 participants (1137 adults, and 298 children). were included between May and August. Median age was 37.7 years (IQR = 29.6-47.7), and 4.92 years (IQR = 1.96-9.53), for the adult and child cohorts, respectively. SARS-CoV-2 was positive in 469 (32.7%) while influenza and RSV were not detected at all. CONCLUSIONS: Measures to reduce SARS-CoV-2 transmission likely exerted a huge impact in the spread of alternate respiratory pathogens. These findings contribute to the knowledge about the dynamics of virus spread. Further, it may be considered for guiding therapeutic choices for these other viruses.

TEMPORAL TREND OF HOSPITALIZATIONS FOR ACUTE BRONCHIOLITIS IN INFANTS UNDER ONE YEAR OF AGE IN BRAZIL BETWEEN 2008 AND 2015.

OBJECTIVE: To evaluate the trend of hospitalization for acute bronchiolitis in infants under one year of age, in the past eight years and after the implementation of the palivizumab immunization program in Brazil. METHODS: The study is a retrospective analysis of data on infants younger than one year of age, who were hospitalized with acute bronchiolitis between 2008 and 2015 in Brazil. The Brazilian National Health System database was used. The rates of hospitalization in the pre-implementation (2008-2012) and post-implementation (2014-2015) periods of the palivizumab immunization program were evaluated. The total number of admissions in the same period was used as a comparison. RESULTS: Between January 2008 and December 2015, 263,679 hospitalizations for bronchiolitis were recorded in infants younger than one year of age, 60% represented by boys. The incidence of hospitalization for bronchiolitis increased by 49% over this period (8.5 to 12.7 per 1,000 inhabitants per year). Between 2013 and 2014, the incidence rate of hospitalization for acute bronchiolitis decreased by 8% (12.5 to 11.5 per 1,000 inhabitants per year). However, in the second year of the program, hospitalization rate increased again by 10% (12.7 per 1,000 inhabitants per years). CONCLUSIONS: Acute bronchiolitis presented increasing rates of hospitalization over the study period. Hospitalization incidence for acute bronchiolitis declined one year after the implementation of palivizumab but increased again in the second year of the program.