Evaluation of patients hospitalized for lower respiratory tract infection due to non-rsv viruses

Background and Aim: Lower respiratory tract infections (LTRIs) are the most important cause of mortality and morbidity in childhood, especially in developing countries. It is known that the LTRIs, which requires hospitalization in early childhood, increases the risk of recurrent wheezing and asthma development. In this study, it was aimed to determine the risk factors for LTRIs, the distribution of viruses in LTRIs, the laboratory findings and the clinical course of the non-RSV viruses, and the frequency of recurrent wheezing and allergic diseases by the questionnaire method in the cases of viral LTRIs requiring hospitalization. Materials and Methods: We studied retrospectively patients at the pediatric wards, Dokuz Eylül University Medical Faculty Hospital between January 1, 2011 to January 1, 2017. Patients aged between 1 and 36 months with a diagnosis of LRTI due to non-RSV viruses were enrolled to our study. Patients' epicrisis and outpatient admissions were evaluated retrospectively. Demographic data of the patients, laboratory and imaging studies, treatments and lenght of hospital stay were recorded in case report form. Parents who agreed to participate in the study were invited to the clinic and responded to the asthma, rhinitis and eczema questionnaires used in the ISAAC (International Study of Asthma and Allergies in Childhood) phase 3 study. Findings: At least one virus was detected in samples from 144 patients and frequencies of detected viruses are respiratory picornaviruses 48.6%, (RV/EV %41 and rhinoviruses %7.6), parainfluenza viruses 16%, adenoviruses 13,9%, metapneumovirus 13.9%, influenza viruses 11.8%, coronaviruses 2.8% and bocavirus 2,1%. More than one virus detected in 9% of patients. Compared to the cases where other viruses were detected; in respiratory picornavirus cases, white blood cell count and neutrophil count were higher (p = 0.011 and p = 0.021, respectively). Lymphocyte count was lower in the presence of influenza virus (p = 0.03). In cases with RV/EV, the number of eosinophils was higher (p = 0.035) and the need for oxygen mechanical ventilation therapy was lower (p = 0.023 and p = 0.012, respectively). The 90 cases that applied the questionnaire were evaluated. There were recurrent wheezing in 77 cases (85.6%) and 29 (32.2%) of them had underlying conditions such as BPD, cystic fibrosis. Recurrent wheezing rate was 78.7% in cases without underlying contidions, and 42% of these cases were hospitalized with first wheezing episode. Cesarean birth was found to increase recurrent wheezing risk (OR: 5,7, p = 0,018, 95% GA: 1,350 - 23,872). No significant association was found between recurrent wheezing and age at admission to the hospital. When the relationship between viruses and recurrent wheezing is evaluated, recurrent wheezing was found more frequently in RV/EV cases (p = 0.046). According to the parents' responses to the ISAAC questionnaire, in the past year 58.9% of the cases had an episode of wheezing, 44.4% had 1 to 3 wheezing episodes, 25.6% had dry cough in the nights without infection and 16.7% had wheezing after exercise. Atopic dermatitis was found in 8.8% and allergic rhinitis was found in 23.3% of cases. Conclusion: Our study has shown that respiratory picornaviruses (rhinoviruses and enteroviruses) play an important role in etiology in hospitalized cases due to LTRI associated with non-RSV viruses. The presence of respiratory picornaviruses (48.6%) and recurrent wheezing (85.6%) in the majority of our cases is consistent with the role of rhinovirus in recurrent wheezing and asthma pathogenesis. Patients who have had severe LTRI with rhinovirus should be carefully monitored in this regard. Key words: Lower respiratory tract infection, recurrent wheezing, respiratory picornavirus