Evaluation of Human Respiratory Syncytial Virus and Human Parainfluenza Virus Type 3 among Hospitalized Children in Northwest of Iran.

Background: Acute respiratory tract infections (ARTIs) are the leading cause of illnesses in children. Human respiratory syncytial virus (HRSV) and human parainfluenza viruses (HPIVs) are among the most common etiologic agents associated with viral respiratory tract infections in children worldwide. Nevertheless, limited information is available on the spread of infections of these two viruses in northwest Iran.

Objective: The purpose of the current study is to evaluate the frequency of RSV and HPIV-3 and clinical features among Iranian children with confirmed respiratory infections between April 2019 and March 2020.

Methods: 100 nasopharyngeal swabs were collected from hospitalized patients (under 5 years old) with ARTI from Tabriz Children's Hospital. Detection of respiratory viruses was performed using the nested RT-PCR method.

Results: Respiratory syncytial virus and HPIV-3 were recognized in 18% (18/100) and 2% (2/100) of children, respectively. Ten (55.6%) of the RSV-positive samples were male, while 8 (44.4%) were female. HPIV-3 was found only among 2 male patients (100%). Most patients (61.1%) with RSV infection were less than 12 months old. Additionally, samples that were positive for HPIV-3 were less than 12 months old. RSV infections had occurred mainly during the winter season.

Conclusions: This study confirms that RSV can be one of the important respiratory pathogens in children in northwestern Iran. However, according to this study, HPIV-3 has a lower prevalence among children in this area than RSV. Therefore, implementing a routine diagnosis for respiratory pathogens can improve the management of respiratory infections in children.