Tehran University of Medical Sciences Iranian Journal of Microbiology 2008-3289 15 1 2023 02 15 155 162 Simin Abbasi Department of Virology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran Nazanin Zahra Shafiei-Jandaghi Department of Virology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran Azadeh Shadab Department of Virology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran Seyed Abbas Hassani Department of Pediatric Intensive Care Unit, Children Medical Center, Tehran University of Medical Sciences, Tehran, Iran Abbas Rahimi Foroushani Department of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran Nazanin Hosseinkhan Endocrine Research Center, Institute of Endocrinology and Metabolism, Iran University of Medical Sciences, Tehran, Iran Fahimeh Aghamir Department of Virology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran Talat Mokhtari-Azad Department of Virology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran Jila Yavarian Department of Virology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran AND Research Center for Antibiotic Stewardship and Antimicrobial Resistance, Tehran University of Medical Sciences, Tehran, Iran 2022 07 13 2022 12 12 Background and Objectives: Human rhinoviruses (HRVs) and human adenoviruses (HAdVs) are among the most prevalent viruses in hospitalized patients with severe acute respiratory infection (SARI). This study aimed to evaluate the molecular characterization of HRV and HAdV in hospitalized patients with SARI, who aged ≤ 18 years in Tehran, Iran. Materials and Methods: To detect these two viruses, a conventional nested RT-PCR (Reverse transcription-polymerase chain reaction) assay was performed on 264 throat swabs collected from December 2018 to March 2019. The epidemiological data were analyzed and phylogenetic trees were constructed. Results: Of 264 cases with SARI, 36 (13.6%) and 28 (10.6%) were positive for HAdV and HRV respectively. Of 21 HRV sequenced samples, HRV-A (42.9%), HRV-B (9.5%) and HRV-C (47.6%) and of 36 HAdV sequenced samples, HAdV-C6 (38.9%), HAdV-B7 (22.2%), HAdV-B3 (11.1%), HAdV-B16 (5.6%), HAdV-C5 (13.9%), HAdV-C57 (5.6%), HAdV-E4 (2.8%); were detected in children with SARI. Some viral genotypes appeared to cause more severe disease, which may lead to hospitalization. Conclusion: Large-scale studies are recommended to investigate the epidemiology and molecular characterizations through surveillance networks to provide useful information on etiology, seasonality, and demographic associations in patients with SARI. https://ijm.tums.ac.ir/index.php/ijm/article/view/3813 https://ijm.tums.ac.ir/index.php/ijm/article/download/3813/1553