Incidence of respiratory viruses in a pediatric population: molecular and epidemiological aspects

Introduction: Respiratory infections are not well defined and the etiology is often unknown. Material and method: four hundred fortynine subjectrs were enrolled in the study; in all patientes there was a suspect of inflammatory diseases of the respiratory tract. At admission, a nasopharyngeal swab was made. A multiplex PCR was performed after extraction and reverse transcription of viral RNA. The amplified fragments were revealed by using an electrophoresis separation. Results: Two hundred and four patients (45.4%) were hospitalized for infection of the upper respiratory tract, 141 (31.4%) for lower respiratory infection and the remaining (23%) for other symptoms. One hundred fiftyseven (35%) patients were positive for human influenza A (H1N1 subtype) and 184 for other respiratory viruses,of which 59 (32%) gave a positive for respiratory syncytial virus, 42 (23%) for rhinovirus, 31 (17%) for parainfluenza virus, 12 (6.5%) for coronavirus, 28 (15%) for adenovirus and 6 (3%) for influenza B (3%) and 6 (3%) for metapneumovirus. The M1 gene sequence of influenza A H1N1 strains from 12 patients had a high identity with that of the reference virus. Conclusion: Furthermore H1N1 and RSV were the main causative agents of acute respiratory infection. A molecular approach provides an accurate and rapid aetiological diagnosis of viral respiratory infections. The molecolar features in the M1 gene suggested that the H1N1 influenza strains circulating in Apulia region had a conserved genetic make up.