Temporal Distribution of Clinical Bronchiolitis in the Jerusalem Area – a Preliminary Report

Objective: Bronchiolitis is a clinical syndrome with a seasonal distribution that varies by location. Data regarding its temporal distribution in Israel are limited, and there are no available data specifically for the Jerusalem area. The aim of this study was to investigate the temporal distribution of cases of bronchiolitis that were clinically diagnosed in a system of urgent-care centers based in and around Jerusalem over eight winters. Methods: A unified database of five urgent-care clinics was queried for the total monthly visits of children aged less than age 2 years with a discharge diagnosis of bronchiolitis, from January 1, 2002 to February 13, 2009. The database was also queried for total monthly visits of all children aged less than 2 years in order to calculate the percentage of patients presenting with bronchiolitis. The frequency distribution was plotted in graph form against months of the years 2002 to early 2009. Results: There was a recurring peak in clinical diagnoses of bronchiolitis in December and January for every year evaluated. Conclusions: Clinical bronchiolitis in the Jerusalem area appears to have a consistent annual peak in December and January. This finding is markedly different from many other reported incidence peaks. Confirmatory virologic studies are needed to determine if the clinical presentation of bronchiolitis in the community reflects the true temporal incidence of the disease. MeSH words: Bronchiolitis, epidemiology, respiratory tract diseases, viral diseases