Abstract
Influenza causes substantial morbidity and mortality. Many original studies have been carried out to estimate disease burden of influenza in mainland China, while the full disease burden has not yet been systematically reviewed. We did a systematic review and meta-analysis to assess the burden of influenza-associated mortality, hospitalization, and outpatient visit in mainland China. We searched 3 English and 4 Chinese databases with studies published from 2005 to 2019. Studies reporting population-based rates of mortality, hospitalization, or outpatient visit attributed to seasonal influenza were included in the analysis. Fixed-effects or random-effects model was used to calculate pooled estimates of influenza-associated mortality depending on the degree of heterogeneity. Meta-regression was applied to explore the sources of heterogeneity. Publication bias was assessed by funnel plots and Egger’s test. We identified 30 studies eligible for inclusion with 17, 8, 5 studies reporting mortality, hospitalization, and outpatient visit associated with influenza, respectively. The pooled influenza-associated all-cause mortality rates were 14.33 and 122.79 per 100,000 persons for all ages and ≥ 65 years age groups, respectively. Studies were highly heterogeneous in aspects of age group, cause of death, statistical model, geographic location, and study period, and these factors could explain 60.14% of the heterogeneity in influenza-associated mortality. No significant publication bias existed in estimates of influenza-associated all-cause mortality. Children aged < 5 years were observed with the highest rates of influenza-associated hospitalizations and ILI outpatient visits. People aged ≥ 65 years and < 5 years contribute mostly to mortality and morbidity burden due to influenza, which calls for targeted vaccination policy for older adults and younger children in mainland China.
Highlights
Seasonal influenza circulates annually and causes substantial morbidity and mortality, with the highest burden among adults aged ≥ 65 years and children aged < 5 years
Many studies have been conducted in China to estimate disease burden of seasonal influenza, the findings vary across different study periods, regions, populations, circulating virus strains, and methodologies[10,13,14]
Keywords included: “influenza”, “burden”, “mortality”, “hospitalization”, “outpatient”, “China”, and other designators to indicate the contribution of influenza, such as “excess”, “associated”, “related”, “attributed”, “attributable”, “confirmed”
Summary
Seasonal influenza circulates annually and causes substantial morbidity and mortality, with the highest burden among adults aged ≥ 65 years and children aged < 5 years. Every year it causes an estimated 3 to 5 million cases of severe illness and 290,000–650,000 respiratory deaths throughout the world[1]. A 2018 systematic review and meta-analysis by Shang et al.[8] estimated the laboratory-confirmed respiratory hospitalizations attributed to influenza among children aged < 18 years in China. A 2019 systematic review by Li et al.[12] described the influenzaassociated mortality rates in mainland China by age group, cause of death, geographic location, and influenza virus type/subtype, but it did not produce synthesized estimates. Our study aims to systematically review the Chinese and English literature of influenza-associated mortality, hospitalization, and outpatient burden in mainland China
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.