Alexander Neal, Dye Christopher, Busch Michael P, Buss Lewis, Prete Carlos A, Brady Oliver J, Mee Paul, Abrahim Claudia M M, Crispim Myuki A E, da Costa Allyson G, Salomon Tassila, Mayaud Philippe, Oikawa Márcio K, Faria Nuno R, Sabino Ester C
Department of Infectious Disease Epidemiology, MRC International Statistics and Epidemiology Group, London School of Hygiene and Tropical Medicine, London, United Kingdom.
Department of Zoology, University of Oxford, Oxford, United Kingdom.
PLoS One. 2025 Jan 15;20(1):e0308319. doi: 10.1371/journal.pone.0308319. eCollection 2025.
Most longitudinal studies of COVID-19 incidence have used unlinked samples. The city of Manaus, Brazil, has a blood donation program which allows sample linkage, and was struck by two large COVID-19 epidemic waves between mid-2020 and early 2021.
We estimated the changing force of infection, i.e. incidence in susceptible individuals. Seroconversion was inferred by a mixture model for serial values from the Abbott Architect SARS-CoV-2 nucleocapsid (N) IgG assay. We estimated the number of suspected COVID-19 hospitalizations arising from each infection over calendar time.
Whole blood donations between April 2020 and March 2021 were included from 6734 people, 2747 with two or more donations. The inferred criterion for seroconversion, and thus an incident infection, was a 6.07 fold increase in N IgG reactivity. The overall force of infection was 1.19 per person year (95% confidence interval 1.14-1.24) during the two main waves. The estimated number of suspected hospitalizations per infection, was approximately 4.1 times higher in the second wave than in the first.
Serial values from this assay can be used to infer seroconversion over time, and in Manaus show a higher number of suspected COVID-19 hospitalizations per infection in the second wave relative to the first.
大多数关于新冠病毒感染发病率的纵向研究使用的是无关联样本。巴西玛瑙斯市有一个献血项目，可实现样本关联，该市在2020年年中至2021年初遭受了两次大规模新冠疫情浪潮冲击。
我们估计了感染力的变化，即易感个体中的发病率。通过雅培Architect SARS-CoV-2核衣壳（N）IgG检测的系列值混合模型推断血清转化情况。我们估计了每个感染在日历时间内导致的疑似新冠病毒住院人数。
纳入了2020年4月至2021年3月期间6734人的全血捐献样本，其中2747人有两次或更多次捐献。推断血清转化（即新发感染）的标准是N IgG反应性增加6.07倍。在两次主要疫情浪潮期间，总体感染力为每人每年1.19（95%置信区间1.14 - 1.24）。每次感染估计的疑似住院人数，在第二波疫情中比第一波高约4.1倍。
该检测的系列值可用于推断随时间的血清转化情况，在玛瑙斯，第二波疫情中每次感染导致的疑似新冠病毒住院人数相对于第一波更高。
