Acute respiratory infections in non-hospitalized children during flu epidemic season

BACKGROUND Among acute respiratory infections (ARI), influenza is the most important, but the circulation of other pathogens must not be underestimated especially in children. Given the common symptomatology, to obtain a rapid and precise etiological diagnosis, the molecular biology assays, allow to detect a wide variety of pathogens in a very short time with high sensitivity and specificity. The aim of the study was to evaluate the circulation of viral or bacterial pathogens, from October 2017 to January 2018. METHODS A pharyngeal swab was performed in non-hospitalized children with ARI-symptomatology at one primary care visit in Parma. Real-Time RT-PCR and Multiplex Real-Time PCR were used to identify influenza A and B viruses, Syncytial Respiratory Virus (RSV) A and B, human Metapneumovirus, human Rhinovirus/Enterovirus, Adenovirus, human Bocavirus, human Coronavirus, human Parainfluenza virus 1-4, Chlamydophila pneumoniae; Mycoplasma pneumoniae; Bordetella pertussis and Legionella pneumophila. The results were stratified by age groups and by surveillance weeks. RESULTS Of the 123 swabs analyzed, 110 (89.4%) were positive for one or more viruses: 54 (49.1%) for influenza B virus, 17 (15.5% ) for subtype A (H1N1) pdm09, 1 (0.9%) for subtype A (H3N2) and 38 (34,5%) for other respiratory viruses like RSV that was the most frequently found (26.40%), followed by Parainfluenza viruses (13.20%). 18.4% of children showed co-infection. No bacteria were identified. Children younger than 5 years showed the highest proportion of viral positive test and among them the highest prevalence of non-influenza respiratory viruses (81.6%) was found. These viruses were prevalent at the beginning of the flu season (44th-51th week) and continued to circulate also during the flu epidemic period. CONCLUSIONS The molecular biology assays showed the intense co-circulation, in the pediatric population, of several respiratory viruses together with flu viruses. A timely diagnosis would allow, in addition to a better description of the ARI's epidemiology, also to address the therapy, avoiding ineffective antibiotics being used to treat these viral forms.