tetano
Editor, Senior Moderator
Influenza Other Respir Viruses
. 2022 Jan 5.
doi: 10.1111/irv.12935. Online ahead of print.
Incidence of medically attended influenza and influenza virus infections confirmed by serology in Ningbo City from 2017-2018 to 2019-2020
Cuiling Xu[SUP] 1 [/SUP], Xuying Lao[SUP] 2 [/SUP], Hongyu Li[SUP] 3 [/SUP], Libo Dong[SUP] 1 [/SUP], Shumei Zou[SUP] 1 [/SUP], Yi Chen[SUP] 2 [/SUP], Yongquan Gu[SUP] 4 [/SUP], Yueqin Zhu[SUP] 5 [/SUP], Pingfeng Xuan[SUP] 6 [/SUP], Weijuan Huang[SUP] 1 [/SUP], Dayan Wang[SUP] 1 [/SUP], Bo Yi[SUP] 2 [/SUP]
Affiliations
Abstract
Objectives: In mainland China, the disease burden of influenza is not yet fully understood. Based on population-based data, we aimed to estimate incidence rates of medically attended influenza and influenza virus infections in Ningbo City.
Methods: We used data for outpatient acute respiratory illness (OARI) from a platform covering all health and medical institutes in Yingzhou District, Ningbo City. We applied generalized additive regression models to estimate influenza-associated excess incidence rate of OARI by age. We recruited local residents aged ≥60 years in the autumn of 2019 and conducted follow-up nearly 9 months later. Every survey, the sera were collected for testing hemagglutination inhibition antibody.
Results: From 2017-2018 to 2019-2020, the annual average of influenza-associated incidence rate of OARI in all ages was 10.9%. The influenza-associated incidence rate of OARI was the highest in 2017-2018 (16.9%) and the lowest in 2019-2020 (4.8%). Regularly, influenza-associated incidence rates of OARI were the highest in children aged 5-14 years (range: 44.1-77.6%) and 0-4 years (range: 8.3-46.6%). The annual average of excess OARI incidence rate in all ages was the highest for influenza B/Yamagata (3.9%). The overall incidence rate of influenza infections indicated by serology in elderly people was 21% during the winter season of 2019-2020.
Conclusions: We identified substantial outpatient influenza burden in all ages in Ningbo. Our cohort study limited in elderly people found that this age group had a high risk of seasonal influenza infections. Our study informs the importance of increasing influenza vaccine coverage in high-risk population including elderly people.
Keywords: China; acute respiratory illness; burden of disease; incidence rates; infection; influenza.
. 2022 Jan 5.
doi: 10.1111/irv.12935. Online ahead of print.
Incidence of medically attended influenza and influenza virus infections confirmed by serology in Ningbo City from 2017-2018 to 2019-2020
Cuiling Xu[SUP] 1 [/SUP], Xuying Lao[SUP] 2 [/SUP], Hongyu Li[SUP] 3 [/SUP], Libo Dong[SUP] 1 [/SUP], Shumei Zou[SUP] 1 [/SUP], Yi Chen[SUP] 2 [/SUP], Yongquan Gu[SUP] 4 [/SUP], Yueqin Zhu[SUP] 5 [/SUP], Pingfeng Xuan[SUP] 6 [/SUP], Weijuan Huang[SUP] 1 [/SUP], Dayan Wang[SUP] 1 [/SUP], Bo Yi[SUP] 2 [/SUP]
Affiliations
- PMID: 34989139
- DOI: 10.1111/irv.12935
Abstract
Objectives: In mainland China, the disease burden of influenza is not yet fully understood. Based on population-based data, we aimed to estimate incidence rates of medically attended influenza and influenza virus infections in Ningbo City.
Methods: We used data for outpatient acute respiratory illness (OARI) from a platform covering all health and medical institutes in Yingzhou District, Ningbo City. We applied generalized additive regression models to estimate influenza-associated excess incidence rate of OARI by age. We recruited local residents aged ≥60 years in the autumn of 2019 and conducted follow-up nearly 9 months later. Every survey, the sera were collected for testing hemagglutination inhibition antibody.
Results: From 2017-2018 to 2019-2020, the annual average of influenza-associated incidence rate of OARI in all ages was 10.9%. The influenza-associated incidence rate of OARI was the highest in 2017-2018 (16.9%) and the lowest in 2019-2020 (4.8%). Regularly, influenza-associated incidence rates of OARI were the highest in children aged 5-14 years (range: 44.1-77.6%) and 0-4 years (range: 8.3-46.6%). The annual average of excess OARI incidence rate in all ages was the highest for influenza B/Yamagata (3.9%). The overall incidence rate of influenza infections indicated by serology in elderly people was 21% during the winter season of 2019-2020.
Conclusions: We identified substantial outpatient influenza burden in all ages in Ningbo. Our cohort study limited in elderly people found that this age group had a high risk of seasonal influenza infections. Our study informs the importance of increasing influenza vaccine coverage in high-risk population including elderly people.
Keywords: China; acute respiratory illness; burden of disease; incidence rates; infection; influenza.