Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, Michigan, USA.
Sustainable Sciences Institute, Managua, Nicaragua.
Clin Infect Dis. 2023 Feb 8;76(3):e1012-e1020. doi: 10.1093/cid/ciac734.
Children constitute an important component of the influenza burden and community transmission, but the frequency of asymptomatic infection and post-influenza sequelae at the community level is poorly understood.
Two community-based prospective cohort studies (2011-2020, 2017-2020) and 1 case-ascertained study (2012-2017) were conducted in Managua, Nicaragua. Non-immunocompromised children aged 0-14 years with ≥1 influenza infections, determined by polymerase chain reaction and hemagglutination inhibition assay, were included.
A total of 1272 influenza infections occurred in the household-based portion of the study. Influenza infection was asymptomatic in 84 (6.6%) infections, and the asymptomatic fraction increased with age (1.7%, 3.5%, and 9.1% for ages 0-1, 2-4, and 5-14, respectively; P < .001). Of asymptomatic children, 43 (51.2%) shed virus, compared to 1099 (92.5%) symptomatic children (P < .001). Also, 2140 cases of influenza occurred in the primary care portion of the study. Sequelae of influenza were rare, with the most common being pneumonia (52, 2.4%) and acute otitis media (71, 3.3%). A/H1N1 had higher age-adjusted odds of acute otitis media (odds ratio [OR] 1.99, 95% confidence interval [CI]: 1.14-3.48; P = .015) and hospitalization (OR 3.73, 95% CI: 1.68-8.67; P = .002) than A/H3N2. B/Victoria had higher age-adjusted odds of pneumonia (OR 10.99, 95% CI: 1.34-90.28; P = .026) than B/Yamagata.
Asymptomatic influenza infection is much less common in children than adults, although viral shedding still occurs in asymptomatic children. Post-influenza sequelae are rare in children in the community setting, and virus strain may be important in understanding the risk of sequelae.
儿童是流感负担和社区传播的重要组成部分，但社区层面上无症状感染和流感后后遗症的发生频率尚不清楚。
在尼加拉瓜马那瓜进行了两项基于社区的前瞻性队列研究（2011-2020 年，2017-2020 年）和一项病例确定研究（2012-2017 年）。纳入了通过聚合酶链反应和血凝抑制试验确定的≥1 次流感感染的 0-14 岁非免疫功能低下儿童。
研究中基于家庭的部分共发生了 1272 例流感感染。流感感染无症状 84 例（6.6%），无症状比例随年龄增加而增加（0-1、2-4 和 5-14 岁分别为 1.7%、3.5%和 9.1%；P<0.001）。在无症状儿童中，43 例（51.2%）排出病毒，而 1099 例（92.5%）症状性儿童（P<0.001）。此外，研究中的初级保健部分还发生了 2140 例流感病例。流感后后遗症罕见，最常见的是肺炎（52 例，2.4%）和急性中耳炎（71 例，3.3%）。与 A/H3N2 相比，A/H1N1 具有更高的年龄调整后急性中耳炎（优势比[OR]1.99，95%置信区间[CI]：1.14-3.48；P=0.015）和住院（OR 3.73，95%CI：1.68-8.67；P=0.002）的风险。与 B/Yamagata 相比，B/Victoria 具有更高的年龄调整后肺炎（OR 10.99，95%CI：1.34-90.28；P=0.026）的风险。
在儿童中，无症状流感感染远不及成人常见，尽管无症状儿童仍会排出病毒。在社区环境中，儿童发生流感后后遗症罕见，病毒株可能对了解后遗症风险很重要。
