ORIGINAL RESEARCH article

Front. Cell. Infect. Microbiol.

Sec. Clinical Microbiology

Volume 15 - 2025 | doi: 10.3389/fcimb.2025.1600990

This article is part of the Research TopicEmerging concepts for respiratory viruses after the pandemicView all 12 articles

Epidemiological, clinical, and molecular analysis of human adenovirus infections in hospitalized children with acute respiratory infections in Tianjin, China

Provisionally accepted
Min  LeiMin Lei1,2Yulian  FangYulian Fang1,2Lu  ZhangLu Zhang1,3Mengzhu  HouMengzhu Hou1,2Ning  WangNing Wang1,2Chunquan  CaiChunquan Cai1,2*
  • 1Tianjin Children's Hospital, Tianjin, China
  • 2Key Laboratory of Birth Defects for Prevention and Treatment, Tianjin Children's Hospital, Tianjin, Tianjin Municipality, China
  • 3Department of Pulmonology, Tianjin Children's Hospital, Tianjin, China

The final, formatted version of the article will be published soon.

Human Adenovirus (HAdV) is a significant pathogen for acute respiratory infections(ARIs) in children. However, its epidemiological patterns, serotype distribution changes, and molecular mechanisms associated with severe pneumonia during and after the COVID-19 pandemic require further elucidation through large-scale and molecular typing studies.This study used a retrospective cohort design to analyze 28060 respiratory specimens from Tianjin Children's Hospital from March 2022 to March 2024. HAdV detection and typing were performed through targeted high-throughput sequencing and PCR-based amplification of Penton, Hexon, and Fiber genes for phylogenetic analysis. Additionally, clinical data were compared to assess differences in clinical presentations among pediatric patients infected with different HAdV types.The overall HAdV detection rate was 8.9% (2,484/28,060), with significant male predominance (9.2% vs. 8.4%, P = 0.019) and age-specific susceptibility peaking in school-aged children (10.4%, P < 0.001). Seasonal patterns demonstrated winter predominance (15.9%), contrasting with other seasons (P < 0.001). Genotyping of 1,914 positive specimens demonstrated HAdV-3 dominance (53.4%, 1,022), followed by HAdV-7 (17.7%, 338), HAdV-2 (8.4%, 160), HAdV-1 (7.9%, 152), and HAdV-21 (6.4%, 122). The diagnosis mainly included pneumonia, bronchitis, adenopharyngitis, and upper respiratory tract infections (URTIs). Genotype-clinical correlations showed distinct patterns: HAdV-3 (55.6%) and HAdV-7 (20.9%) predominated in pneumonia cases, with HAdV-7 linked to severe pneumonia (P<0.001). HAdV-3 (40.6%) and HAdV-2 (16.7%) were more common in adenopharyngitis, while HAdV-3 and HAdV-21 were more common in bronchitis (51.2% and 11.1%) and URTIs (31.9% and 19.1%). Molecular characterization revealed structural conservation in the Penton protein of HAdV-C and identified Hexon as the most polymorphic region with 85 variable sites, indicating divergent evolutionary pressures across viral domains.HAdV-3, HAdV-7, HAdV-2, and HAdV-1 were the predominant HAdV types in children hospitalized with ARIs in Tianjin. Moreover, not only the epidemiological characteristics of different HAdV types vary, but there are also certain differences in the clinical symptoms and outcomes of children infected with different types of HAdV. Therefore, it is essential to differentiate HAdV types for epidemiological surveillance and clinical management purposes.

Keywords: Human adenovirus, acute respiratory infections, Children, Epidemiology, Molecular types

Received: 27 Mar 2025; Accepted: 17 Jun 2025.

Copyright: © 2025 Lei, Fang, Zhang, Hou, Wang and Cai. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: Chunquan Cai, Tianjin Children's Hospital, Tianjin, China

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