Etiology, Seasonality, and Clinical Features of Viral Respiratory Tract Infections in Children Hospitalized With Acute Bronchiolitis: A Single-Center Study

Gökçe, Sule; Kurugöl, Zafer; Koturoglu, Güldane; Çiçek, Candan; Aslan, Asli

Acute bronchiolitis (AB), which is the most common acute lower respiratory system disease in infants, is often caused by a viral infection. It is especially the leading cause of hospitalization in infants under 6 months of age. 1, 2 Epidemic peaks of AB are frequently seen during the winter season. Respiratory syncytial virus (RSV) is usually the cause of 50% to 80% of the cases, but other viruses including adenovirus, influenza virus, and parainfluenza virus have also been reported to cause AB as the sole pathogen or as coinfection with or without RSV. 3, 4 With various polymerase chain reaction (PCR) techniques, possible new agents like rhinovirus, human metapnomovirus, human bocavirus, Bordatella pertussis, and atypical pathogens were also described as the leading causes of AB. [5] [6] [7] Having a cardiovascular disease, chronic pulmonary disease, immunodeficiency, and premature birth increase the risk of AB-associated respiratory failure, or even death. 8 The World Health Organization has reported that RSV is the causative pathogen for over 30 million new acute lower respiratory infection episodes in children under 5 years of age and it gives rise to more than 3.4 million hospital admissions and 160 000 deaths every year. 9, 10 The diagnosis of AB is made based on typical history with wheezing and characteristic clinical features such as tachypnea, nasal flaring, chest retractions, and wheezing and/or rales followed by a viral upper respiratory infection in infants. The American Academy of Pediatrics (AAP) 2006 11 Chest radiographs and laboratory studies may be thought of on clinical suspicion after evaluating the differential diagnosis for secondary or comorbid bacterial infection, complications, or other conditions. Viral diagnosis methods including antigen detection or immunofluorescence of nasal secretion wash or nasal aspiration, rapid antigen tests, and PCR are only suggested for identifying specific viral agents in children with bronchiolitis if the results will determine discontinuation of palivizumab prophylaxis, initiation or continuation/discontinuation of antibiotic therapy. [12] [13] [14] [15] Majority of studies have recently researched the burden of respiratory viral tract infection agents in AB with larger groups. In these studies, epidemiological, clinical, and risk factors of AB have also been defined. So, it can be said that AB is frequent in infancy and that there is an increase in the number of admissions to hospitals and bronchiolitis-related morbidity.