Influenza-associated mortality

This profile concerns mortality associated with influenza virus infection rather than a separate pathogen-specific disease entity ^[1][2]. The sources characterize influenza as a viral infection linked to high morbidity and mortality, and one review notes that influenza-associated mortality is a recognized outcome burden in surveillance and burden studies ^[4][1]. The provided material does not supply a formal case definition, ICD coding, or a more granular etiologic breakdown beyond influenza virus infection and influenza B-associated excess mortality ^[3][1][2].

The source material does not provide a detailed clinical syndrome description for fatal influenza cases, so source-backed symptom or complication profiles are not yet available ^[4][1][2]. What is supported is that influenza is associated with high morbidity and mortality, and that the mortality burden is especially high among older adults, children, and patients with chronic diseases ^[4][2]. In mainland China, pooled influenza-associated all-cause mortality was estimated at 14.33 per 100,000 persons overall and 122.79 per 100,000 among persons aged 65 years and older, indicating a marked age gradient in fatal burden ^[1]. A Hong Kong analysis of influenza B found that the majority of excess deaths were respiratory and that most excess deaths occurred in adults aged 65 years and older ^[3].

Influenza-associated mortality has been described as a substantial public-health burden in multiple settings, including mainland China and Hong Kong ^[1][3]. A systematic review of mainland China studies identified 30 eligible studies, with 17 reporting mortality, and found that estimates were highly heterogeneous by age group, cause of death, statistical model, geographic location, and study period ^[1]. In global review literature, influenza virus infection is described as causing about 500,000 deaths annually worldwide ^[2]. The Hong Kong influenza B study further indicates ongoing annual mortality burden between 2014 and 2023, with an average of 260 excess deaths per year associated with influenza B and a higher burden from B/Yamagata than B/Victoria ^[3].

The provided sources do not describe transmission routes in detail for influenza-associated mortality itself ^[4][1][2]. They do support that the mortality burden arises in the context of influenza virus infection, including seasonal influenza and influenza B epidemics ^[1][3]. Source-backed detail on specific exposure mechanisms, infectious period, or setting-specific transmission is not yet available ^[4][1][2].

The source material identifies higher mortality burden among the elderly, children, and patients with chronic diseases ^[2]. In quantitative burden estimates from mainland China and Hong Kong, adults aged 65 years and older accounted for the highest rates or the majority of excess deaths ^[1][3]. Beyond these groups, source-backed detail on other high-risk populations is not yet available from the provided snippets ^[4][1][2].

The source snippets do not provide a public-health prevention package specific to influenza-associated mortality, such as vaccination schedules, respiratory precautions, or antiviral policy ^[4][1][2]. They do, however, indicate that additional therapeutic strategies are being sought to reduce the burden on health systems, and that ongoing statin treatment has been studied as a potential modifier of influenza prevalence and mortality ^[4]. Because the supplied evidence does not establish prevention efficacy or recommend a control measure, source-backed preventive detail is not yet available ^[4].

For surveillance purposes, influenza-associated mortality should be read as a burden outcome that may be estimated from all-cause, cause-specific, or excess-mortality methods rather than from a single uniform case definition ^[1][3]. The mainland China meta-analysis explicitly notes heterogeneity in age group, cause of death, statistical model, geographic location, and study period, which can materially affect estimates and comparability ^[1]. The Hong Kong influenza B study demonstrates that lineage-specific activity can be linked to excess mortality, with respiratory deaths predominating and older adults accounting for most excess deaths ^[3].

1. 1 Li J et al. Influenza-associated disease burden in mainland China: a systematic review and meta-analysis. Sci Rep. 2021 Feb 3. PMID: 33536462. doi: 10.1038/s41598-021-82161-z. PubMed: https://pubmed.ncbi.nlm.nih.gov/33536462/
2. 2 Chua SCJH et al. A Review and Meta-Analysis of Influenza Interactome Studies. Front Microbiol. 2022. PMID: 35531276. doi: 10.3389/fmicb.2022.869406. PubMed: https://pubmed.ncbi.nlm.nih.gov/35531276/
3. 3 Influenza-associated Excess Mortality Associated With Influenza B in Hong Kong, 2014–2023. The Journal of Infectious Diseases. 2025. doi: 10.1093/infdis/jiaf414. DOI: https://doi.org/10.1093/infdis/jiaf414
4. 4 Vahedian-Azimi A et al. The effect of statins on the prevalence and mortality of influenza virus infection: a systematic review and meta-analysis. Arch Med Sci. 2022. PMID: 36457966. doi: 10.5114/aoms/149633. PubMed: https://pubmed.ncbi.nlm.nih.gov/36457966/
5. 5 Challenges in reducing influenza-associated mortality. The Lancet. 2018. doi: 10.1016/s0140-6736(17)33292-0. DOI: https://doi.org/10.1016/s0140-6736(17)33292-0
6. 6 Influenza‐Associated Mortality in Hong Kong. Clinical Infectious Diseases. 2004. doi: 10.1086/425315. DOI: https://doi.org/10.1086/425315

ICD-10

ICD-11

Total cases

532

Peak month

2020-02

Coverage

1 reporting countries · 2019-01-05 → 2026-06-20