Tehran University of Medical Sciences Iranian Journal of Microbiology 2008-3289 18 3 2026 06 07 375 381 Marjan Tariverdi Department of Pediatrics, Clinical Research Development Center of Children's Hospital, Hormozgan University of Medical Sciences, Bandar Abbas, Iran Mohammad Tamaddondar Department of Nephrology, School of Medicine, Hormozgan University of Medical Sciences, Bandar Abbas, Iran Dariush Hooshyar Student Research Committee, Faculty of Medicine, Hormozgan University of Medical Sciences, Bandar Abbas, Iran Mahsa Fallahi Department of Pediatrics, Clinical Research Development Center of Children's Hospital, Hormozgan University of Medical Sciences, Bandar Abbas, Iran Mohammad Bagher Rahmati Department of Pediatrics, Clinical Research Development Center of Children's Hospital, Hormozgan University of Medical Sciences, Bandar Abbas, Iran Maryam Mohammadian Hakami Department of Pediatrics, Clinical Research Development Center of Children's Hospital, Hormozgan University of Medical Sciences, Bandar Abbas, Iran Ali Asgari Department of Pediatrics, Clinical Research Development Center of Children's Hospital, Hormozgan University of Medical Sciences, Bandar Abbas, Iran Hossein Abdollahi Student Research Committee, Faculty of Medicine, Hormozgan University of Medical Sciences, Bandar Abbas, Iran 2025 11 17 2026 05 11 Background and Objectives: Rotavirus is a major cause of acute gastroenteritis in children. This study assessed the frequency and clinical characteristics of rotavirus infection in children under five years old. Materials and Methods: This cross-sectional study was conducted in 2020 on children with acute gastroenteritis. Clinical and demographic data were collected, dehydration severity was assessed by a pediatrician, and stool samples obtained within 48 hours of admission were tested for rotavirus antigen using ELISA. Results: A total of 301 children with acute gastroenteritis were included. Rotavirus antigen was detected in 34.6% of cases. Vomiting (81.2%) and diarrhea (96.1%) were significantly common among rotavirus-positive children (p = 0.01). Severe dehydration (>10%) and the need for parenteral rehydration were observed more frequently among rotavirus-positive children compared with rotavirus-negative cases (20.9% vs. 9.2%, p = 0.02 and 91.1% vs. 78.1%, p = 0.01, respectively). However, these findings should be interpreted cautiously, as clinical severity may also have been influenced by other demographic and clinical factors. Conclusion: Rotavirus was detected in a considerable proportion of children with acute gastroenteritis in southern Iran. Rotavirus-positive cases showed more frequent severe dehydration, although this finding should be interpreted cautiously. Early assessment and supportive care remain important. https://ijm.tums.ac.ir/index.php/ijm/article/view/5943 https://ijm.tums.ac.ir/index.php/ijm/article/download/5943/1897