2021-2022 年甲型流感病毒的家庭传播。

Household Transmission of Influenza A Viruses in 2021-2022.

机构信息

Influenza Division, Centers for Disease Control and Prevention, Atlanta, Georgia.

Vanderbilt University Medical Center, Nashville, Tennessee.

出版信息

JAMA. 2023 Feb 14;329(6):482-489. doi: 10.1001/jama.2023.0064.

DOI:10.1001/jama.2023.0064

PMID:36701144

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC9880862/

Abstract

IMPORTANCE

Influenza virus infections declined globally during the COVID-19 pandemic. Loss of natural immunity from lower rates of influenza infection and documented antigenic changes in circulating viruses may have resulted in increased susceptibility to influenza virus infection during the 2021-2022 influenza season.

OBJECTIVE

To compare the risk of influenza virus infection among household contacts of patients with influenza during the 2021-2022 influenza season with risk of influenza virus infection among household contacts during influenza seasons before the COVID-19 pandemic in the US.

DESIGN, SETTING, AND PARTICIPANTS: This prospective study of influenza transmission enrolled households in 2 states before the COVID-19 pandemic (2017-2020) and in 4 US states during the 2021-2022 influenza season. Primary cases were individuals with the earliest laboratory-confirmed influenza A(H3N2) virus infection in a household. Household contacts were people living with the primary cases who self-collected nasal swabs daily for influenza molecular testing and completed symptom diaries daily for 5 to 10 days after enrollment.

EXPOSURES

Household contacts living with a primary case.

MAIN OUTCOMES AND MEASURES

Relative risk of laboratory-confirmed influenza A(H3N2) virus infection in household contacts during the 2021-2022 season compared with prepandemic seasons. Risk estimates were adjusted for age, vaccination status, frequency of interaction with the primary case, and household density. Subgroup analyses by age, vaccination status, and frequency of interaction with the primary case were also conducted.

RESULTS

During the prepandemic seasons, 152 primary cases (median age, 13 years; 3.9% Black; 52.0% female) and 353 household contacts (median age, 33 years; 2.8% Black; 54.1% female) were included and during the 2021-2022 influenza season, 84 primary cases (median age, 10 years; 13.1% Black; 52.4% female) and 186 household contacts (median age, 28.5 years; 14.0% Black; 63.4% female) were included in the analysis. During the prepandemic influenza seasons, 20.1% (71/353) of household contacts were infected with influenza A(H3N2) viruses compared with 50.0% (93/186) of household contacts in 2021-2022. The adjusted relative risk of A(H3N2) virus infection in 2021-2022 was 2.31 (95% CI, 1.86-2.86) compared with prepandemic seasons.

CONCLUSIONS AND RELEVANCE

Among cohorts in 5 US states, there was a significantly increased risk of household transmission of influenza A(H3N2) in 2021-2022 compared with prepandemic seasons. Additional research is needed to understand reasons for this association.

摘要

重要性

在 COVID-19 大流行期间，全球流感病毒感染率下降。由于感染流感的频率降低，自然免疫力下降，以及循环病毒的抗原性变化，在 2021-2022 年流感季节，人们可能更容易感染流感病毒。

目的

比较美国 2021-2022 年流感季节中流感患者家庭接触者感染流感病毒的风险与 COVID-19 大流行前流感季节中家庭接触者感染流感病毒的风险。

设计、地点和参与者：这项前瞻性流感传播研究在 COVID-19 大流行前的 2 个州（2017-2020 年）和美国的 4 个州在 2021-2022 年流感季节招募了家庭。主要病例是家庭中最早实验室确诊的甲型 H3N2 流感病毒感染患者。家庭接触者是与主要病例同住的人，他们每天自行采集鼻拭子进行流感分子检测，并在入组后 5 至 10 天内每天填写症状日记。

暴露

与主要病例同住的家庭接触者。

主要结果和测量指标

与大流行前季节相比，2021-2022 年季节中家庭接触者感染甲型 H3N2 流感病毒的相对风险。风险估计值根据年龄、疫苗接种状况、与主要病例的互动频率以及家庭密度进行了调整。还进行了年龄、疫苗接种状况和与主要病例互动频率的亚组分析。

结果

在大流行前的季节中，纳入了 152 例主要病例（中位年龄为 13 岁；3.9%为黑人；52.0%为女性）和 353 例家庭接触者（中位年龄为 33 岁；2.8%为黑人；54.1%为女性），在 2021-2022 年流感季节中，纳入了 84 例主要病例（中位年龄为 10 岁；13.1%为黑人；52.4%为女性）和 186 例家庭接触者（中位年龄为 28.5 岁；14.0%为黑人；63.4%为女性）。在大流行前的流感季节中，20.1%（71/353）的家庭接触者感染了甲型 H3N2 病毒，而在 2021-2022 年，186 例家庭接触者中有 50.0%（93/186）感染了甲型 H3N2 病毒。2021-2022 年与大流行前季节相比，甲型 H3N2 病毒感染的调整后相对风险为 2.31（95%CI，1.86-2.86）。