Clinical-etiological characteristics of hospitalized pediatric patients with a diagnosis of bronchiolitis in Santa Fe, Argentina

Introduction: Bronchiolitis is one of the main causes of Acute Lower Respiratory Infections (ALRI) in pediatrics, and is responsible for a significant proportion of hospitalizations in infants, mainly in children under 1 year of age. Its diagnosis is clinical. The disease is characterized by a wide variety and degree of signs and symptoms. Objective: To describe the clinical-etiological characteristics of cases of bronchiolitis in children under 1 year of age, admitted to a children's hospital in the city of Santa Fe, over a period of one year. Materials and Methods: This was an observational and cross-sectional study. Demographic, clinical and laboratory data from epidemiological surveillance medical records were analyzed. The diagnostic techniques used, based on the viral agent, were real-time RT-PCR, end-point PCR and Indirect Immunofluorescence. Results: Out of a total of 108 cases, 90.7% were between 1 and 6 months old. The median hospital stay was 5 days, and premature birth was the most common prior medical condition. 78.7% (85) had a positive viral diagnosis, with Rhinovirus (hRV) and Respiratory Syncytial Virus (RSV) being the most prevalent agents, both in single infection and coinfection. Oxygen therapy time was longer in the most seriously ill patients (p<0.001). 32.4% (35) received some medication, which was, most frequently, antibiotics. A positive and significant association was found between age less than 3 months and hospitalization longer than 5 days (OR=2.5; CI: 1.1-5.8; p=0.02); and between a positive RSV diagnosis and a severe condition (OR: 7.7; CI: 1.95-39.6; p<0.001). Conclusions: The characteristics and medical conditions considered by the literature as risk factors for the morbidity and severity of a ALRI were found more frequently in the study population. hRV and RSV were the most commonly-detected viral agents. We found a positive association between RSV infection and the severity of the condition.