Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil.
Department of Nutrition, School of Public Health, University of São Paulo, São Paulo, Brazil.
PLoS Negl Trop Dis. 2022 Jul 18;16(7):e0010580. doi: 10.1371/journal.pntd.0010580. eCollection 2022 Jul.
The epidemiology of childhood SARS-CoV-2 infection and COVID-19-related illness remains little studied in high-transmission tropical settings, partly due to the less severe clinical manifestations typically developed by children and the limited availability of diagnostic tests. To address this knowledge gap, we investigate the prevalence and predictors of SARS-CoV-2 infection (either symptomatic or not) and disease in 5 years-old Amazonian children.
METHODOLOGY/PRINCIPAL FINDINGS: We retrospectively estimated SARS-CoV-2 attack rates and the proportion of infections leading to COVID-19-related illness among 660 participants in a population-based birth cohort study in the Juruá Valley, Amazonian Brazil. Children were physically examined, tested for SARS-CoV-2 IgG and IgM antibodies, and had a comprehensive health questionnaire administered during a follow-up visit at the age of 5 years carried out in January or June-July 2021. We found serological evidence of past SARS-CoV-2 infection in 297 (45.0%; 95% confidence interval [CI], 41.2-48.9%) of 660 cohort participants, but only 15 (5.1%; 95% CI, 2.9-8.2%) seropositive children had a prior medical diagnosis of COVID-19 reported by their mothers or guardians. The period prevalence of clinically apparent COVID-19, defined as the presence of specific antibodies plus one or more clinical symptoms suggestive of COVID-19 (cough, shortness of breath, and loss of taste or smell) reported by their mothers or guardians since the pandemic onset, was estimated at 7.3% (95% CI, 5.4-9.5%). Importantly, children from the poorest households and those with less educated mothers were significantly more likely to be seropositive, after controlling for potential confounders by mixed-effects multiple Poisson regression analysis. Likewise, the period prevalence of COVID-19 was 1.8-fold (95%, CI 1.2-2.6-fold) higher among cohort participants exposed to food insecurity and 3.0-fold (95% CI, 2.8-3.5-fold) higher among those born to non-White mothers. Finally, children exposed to household and family contacts who had COVID-19 were at an increased risk of being SARS-CoV-2 seropositive and-even more markedly-of having had clinically apparent COVID-19 by the age of 5 years.
CONCLUSIONS/SIGNIFICANCE: Childhood SARS-CoV-2 infection and COVID-19-associated illness are substantially underdiagnosed and underreported in the Amazon. Children in the most socioeconomically vulnerable households are disproportionately affected by SARS-CoV-2 infection and disease.
在高传播的热带地区，儿童 SARS-CoV-2 感染和 COVID-19 相关疾病的流行病学仍研究甚少，部分原因是儿童通常表现出较轻的临床症状，以及诊断测试的可用性有限。为了解决这一知识空白，我们调查了亚马逊 5 岁儿童的 SARS-CoV-2 感染（有症状或无症状）和疾病的患病率和预测因素。
方法/主要发现：我们回顾性估计了在巴西亚马逊 Juruá 谷进行的一项基于人群的出生队列研究中 660 名参与者的 SARS-CoV-2 攻击率和导致 COVID-19 相关疾病的感染比例。在 2021 年 1 月或 6 月至 7 月进行的 5 岁随访访问中，对儿童进行了体格检查、检测 SARS-CoV-2 IgG 和 IgM 抗体，并进行了全面的健康问卷调查。我们发现 660 名队列参与者中有 297 名（45.0%；95%置信区间 [CI]，41.2-48.9%）有过去 SARS-CoV-2 感染的血清学证据，但只有 15 名（5.1%；95% CI，2.9-8.2%）血清阳性儿童的母亲或监护人报告了之前有 COVID-19 的医疗诊断。自大流行开始以来，通过母亲或监护人报告存在特定抗体加上一种或多种提示 COVID-19（咳嗽、呼吸急促和味觉或嗅觉丧失）的临床症状定义的临床明显 COVID-19 的期间患病率估计为 7.3%（95% CI，5.4-9.5%）。重要的是，在控制了混合效应多项泊松回归分析中的潜在混杂因素后，来自最贫困家庭的儿童和母亲受教育程度较低的儿童更有可能呈血清阳性。同样，在经历了食物不安全的暴露的队列参与者中，COVID-19 的期间患病率要高出 1.8 倍（95% CI 1.2-2.6 倍），而母亲为非白人的参与者中 COVID-19 的期间患病率要高出 3.0 倍（95% CI 2.8-3.5 倍）。最后，与家中和家庭接触的 COVID-19 患者有接触的儿童患 SARS-CoV-2 血清阳性的风险增加，并且在 5 岁时出现临床明显 COVID-19 的风险甚至更高。
结论/意义：在亚马逊地区，儿童 SARS-CoV-2 感染和 COVID-19 相关疾病的诊断和报告严重不足。来自最弱势社会经济家庭的儿童受 SARS-CoV-2 感染和疾病的影响不成比例。
