Evidence map›Paper›PMID 41547731›Full record

ArticleBMC infectious diseases2026

Resurgence and clinical evolution of influenza A in Chinese children: shifting epidemiology and serological dynamics across pre-, intra-, and post-pandemic eras (2019-2023).

Guiling Xu, Yu Chen, Yu Zhu, Qing Fang, Xiaotong Xue, Kejun Hu, Sha Zhou, Li Hong, Ying Xiang

Abstract read
In one paragraph

Article in BMC infectious diseases, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

1 citing paper in PubMed.

  1. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

9 authors.

Guiling Xu *Department of Internal Medicine, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, 200127, China.
Yu Chen *Department of Pediatrics, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, 200062, China.
Yu Zhu *Department of Gastroenterology, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, 200127, China.
Qing FangDepartment of Laboratory Medicine, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, 200127, China.
Xiaotong XueDepartment of Laboratory Medicine, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, 200127, China.
Kejun HuDepartment of Laboratory Medicine, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, 200127, China.
Sha Zhou *Administration Department of Nosocomial Infection, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, 200127, China.
Li Hong *Department of Clinical Nutrition, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, 200127, China.
Ying Xiang *Department of Laboratory Medicine, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, 200127, China. xiangying@scmc.com.cn.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

objectiveThis study aimed to analyze the epidemiological characteristics and hematologic and inflammatory markers of influenza A in children aged 0–18 years before and after the COVID-19 pandemic to guide future prevention and control strategies.

methodsWe conducted a single-center retrospective analysis of 238,494 children tested for influenza A at Shanghai Children’s Medical Center (2019.1-2023.12). Positivity rates and serological parameters were evaluated across age groups seasons, and years.

resultsDuring the pandemic period, influenza A positivity remained consistently low without seasonal peaks. Conversely, post-pandemic positivity (33.3% in 2023) markedly exceeded pre-pandemic levels (13.7% in 2019), exhibiting winter-spring seasonality with bimodal peaks in February-March and December. School-aged children (≥ 6 years) indicated the highest post-pandemic positivity rate (38.9%). Hospitalization rates among influenza A-positive children inversely correlated with age: 16.7% in neonates (≤ 28 days) vs. 1.4% in infants (29d-3y) vs. 0.4% in preschoolers (3-6y) vs. 0.33% in older children (≥ 6y). Children < 6 years predominated in severe diagnoses and comorbid conditions.

conclusionsThis study delineates the evolving epidemiology of influenza A from 2019 to 2023. Post-pandemic resurgence suggested heightened positivity rates and prolonged seasonal activity exceeding pre-pandemic patterns. Young children and those with comorbidities exhibited greater disease severity requiring hospitalization. Enhanced pediatric influenza A prevention is imperative. CLINICAL TRIAL NUMBER: Not applicable. This study is a retrospective observational study and does not meet the definition of a clinical trial requiring registration.

Indexed as

COVID-19Influenza A virusInfluenza, HumanAdolescentChildChild, PreschoolChinaEast Asian PeopleFemaleHospitalizationHumansInfantInfant, NewbornMalePandemicsRetrospective StudiesCovid-19Immune debtInfluenza APediatric

Identifiers

PMID41547731
PMCPMC12895727

What OpenQuestion holds

Textmetadata
LicenceCC BY-NC-ND
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.