Viral etiology of acute asthma exacerbation

Abstract

Background : Respiratory viruses are well recognized as major trig-gers of acute exacerbations of asthma in children, resulting in frequent out- patients visits and hospitalizations. We aimed to deter-mine the distribution of viruses that cause of lower respiratory tract infections for patients with acute asthma exacerbation. Method : Totally 104 patients over the age of 5 and diagnosed with asthma were involved in this study. All patients were applied for asthma exacerbation and hospitalized at our Pediatric Immunology and Allergy Unit at between February 2017- 2020. Polymerase chain reaction (PCR) was used to determine the viral agents for all pa-tients. Nasopharyngeal aspirate was collected and assessed by PCR. Results : Forty- eight of the patients were female (46.1%). The mean age was 108.9 ± 37 months. At least one viral agent was identified at 56.7% of patients (n = 59). There were more than one responsible viruses for 5 patients. Human Rhinovirus (HRV) was the most com-mon virus that determined (n = 44, 42.3%). Respectively, Respiratory Syncytial Virus (n = 8; %7.6), Human Metapneumovirus (n = 4; %3.8), Influenza (n = 6; 5.7%), Parainfluenza (n = 1; 0.9%), Enterovirus (n = 1; 0.9%), Adenovirus (n = 1; 0.9%) were determined. Forty- three of patients (41.3%) had atopic asthma and a viral agent was determined at 24 of them (55.8%). Rhinovirus was responsible at 18 of them (41.8%). Ratio of allergic asthma was 42.2% for pa-tients who had no viral trigger. The mean hospitalization day was 7.79 ± 2.9 day. There were no statistically significant differences be-tween hospitalization day and viral and non- viral lower respiratory tract infection, HRV and non- HRV, allergic and non- allergic asthma ( P > .05). Conclusion : Human Rhinovirus infection has been emerged as an important cause of asthma exacerbation. However, identification of the virus causing acute asthma attack was not correlated with the duration of hospitalization. In addition, whether asthma is allergic or not does not affect the type of virus that triggers.