[Epidemiology of patients hospitalised due to bronchiolitis in the south of Europe: Analysis of the epidemics, 2010-2015].

Introduction: The renewal of clinical practice guidelines on acute bronchiolitis (AB) requires the re-assessment of the consequences of their implementation. An update is presented on the main clinical and epidemiological variables in patients hospitalised due to AB in Southern Europe and an analysis made of the causes associated with longer hospital stay.

Patients And Method: A retrospective study was conducted on patients admitted to hospital due to AB during 5 epidemics (2010-2015), with an analysis of the major clinical and epidemiological variables. A logistic regression analysis was performed on the factors associated with a longer hospital stay.

Results: The beginning of the epidemic occurred between the 4th week of September and the 3rd week of October. Of those children under 2 years (42,530), 15.21% (6,468 patients) attended paediatric emergency department due to having AB, and 2.36% (1,006 patients) were admitted. Of these, 18.5% of were premature, 12.2% had a birth weight <2,300g, 21.1% were younger than 1 month, 10.8% consulted for associated apnoea, 31.1% had an intake <50%, and 13.1% had bacterial superinfection. These factors were independently associated with prolonged stay. The median length of stay was 5 days, and 8.5% of cases were admitted to a paediatric intensive care unit (PICU).

Conclusions: The beginning of the bronchiolitis epidemic showed a variability of up to 4 weeks in this region. Five years after implementing the new guidelines, the incidence of admissions was approximately 2.3%, and appeared stable compared to previous studies. The mean age of the patients decreased to 2.4 months, although with a similar proportion of PICU admissions of 8.5%. Independent factors associated with prolonged stay were: low birth weight, age less than one month, apnoea prior-to-admission, intake of less than 50%, and severe bacterial superinfection. Respiratory bacterial infection exceeded the prevalence of urinary tract infection.