Assessing the burden of bronchiolitis and lower respiratory tract infections in children ≤24 months of age in Italy, 2012–2019

Abstract

BackgroundBronchiolitis is the most common lower respiratory tract infection (LRTI) in children and is mainly caused by the Respiratory Syncytial Virus (RSV). Bronchiolitis presents seasonally and lasts about five months, usually between October to March, with peaks of hospitalizations between December and February, in the Northern Hemisphere. The burden of bronchiolitis and RSV in primary care is not well understood.Materials and methodsThis retrospective analysis used data from Pedianet, a comprehensive paediatric primary care database of 161 family paediatricians in Italy. We evaluated the incidence rates (IR) of all-cause bronchiolitis (ICD9-CM codes 466.1, 466.11 or 466.19), all-cause LRTIs, RSV-bronchiolitis and RSV-LRTIs in children from 0 to 24 months of age, between January 2012 to December 2019. The role of prematurity (<37 weeks of gestational age) as a bronchiolitis risk factor was evaluated and expressed as odds ratio.ResultsOf the 108,960 children included in the study cohort, 7,956 episodes of bronchiolitis and 37,827 episodes of LRTIs were recorded for an IR of 47 and 221 × 1,000 person-years, respectively. IRs did not vary significantly throughout the eight years of RSV seasons considered, showing a seasonality usually lasting five months, between October and March, while the peak of incidence was between December and February. Bronchiolitis and LRTI IRs were higher during the RSV season, between October and March, regardless of the month of birth, with bronchiolitis IR being higher in children aged ≤12 months. Only 2.3% of bronchiolitis and LRTI were coded as RSV-related. Prematurity and comorbidity increased the risk of bronchiolitis; however, 92% of cases happened in children born at term, and 97% happened in children with no comorbidities or otherwise healthy.ConclusionsOur results confirm that all children aged ≤24 months are at risk of bronchiolitis and LRTI during the RSV season, regardless of the month of birth, gestational age or underlying health conditions. The IRs of bronchiolitis and LRTI RSV-related are underestimated due to the poor outpatient epidemiological and virological surveillance. Strengthening the surveillance system at the paediatric outpatient level, as well as at the inpatient level, is needed to unveil the actual burden of RSV-bronchiolitis and RSV-LRTI, as well as to evaluate the effectiveness of new preventive strategies for anti-RSV.

Clinical and economic burden of respiratory syncytial virus in children aged 0–5 years in Italy

“…Additional risk factors for RSV-LRTIs are preterm birth, congenital heart disease (CHD), chronic lung disease (CLD) or bronchopulmonary dysplasia (BPD), and other specific and severe diseases leading to immune and neuromuscular deficits [ 1 , 13 , 14 ]. Actually, as confirmed by recent Italian studies, almost 9 out of 10 infants hospitalized for RSV [ 10 ] and even more that 9 out of 10 infants with LRTIs visited at family pediatrician [ 15 ] were full-term born or otherwise healthy. This segmentation of the RSV-LRTIs burden retrieved in Italy is in line with the evidence available in the literature and studies from the Centers for Disease Control and Prevention (CDC) in USA [ 16 – 18 ].…”

Predictors of prolonged length of hospital stay and in-hospital mortality in patients aged 1–24 months with acute bronchiolitis in Douala, Cameroon

“…Moreover, mortality from RSV bronchiolitis has been reported to be different from mortality from other viral-induced bronchiolitis [ 18 ] and therefore, lack of viral testing in our study was a significant limitation. Moreover, although sometimes reported in all patients aged < 24 months [ 57 ], bronchiolitis typically affects infants aged 1-12months. Our sample also included patients aged 12–24 months and therefore our results may represent RSV induced Lower Respiratory Tract Infections (LRTI)) rather than bronchiolitis.…”

Assessing the Burden of Respiratory Syncytial Virus-related Bronchiolitis in Primary Care and at 15-Day and 6-Month Follow-up Before Prophylaxis in France: A Test-negative Study

“…4 Studies assessing the burden of RSV-related diseases have focused on hospitalized patients, which concerns 2% to 3% of bronchiolitis cases. 4,5 By contrast, data on bronchiolitis in outpatient settings are scarce. 6–12 Of note, the evaluation of RSV-related diseases in ambulatory care has been mainly limited by the lack of RSV testing ability in outpatient settings globally and in France.…”