Muñoz-Medina José Esteban, Grajales-Muñiz Concepción, Salas-Lais Angel Gustavo, Fernandes-Matano Larissa, López-Macías Constantino, Monroy-Muñoz Irma Eloísa, Santos Coy-Arechavaleta Andrea, Palomec-Nava Iliana Donají, Duque-Molina Célida, Madera-Sandoval Ruth Lizzeth, Rivero-Arredondo Vanessa, González-Ibarra Joaquín, Alvarado-Yaah Julio Elías, Rojas-Mendoza Teresita, Santacruz-Tinoco Clara Esperanza, González-Bonilla Cesar Raúl, Borja-Aburto Víctor Hugo
División de Laboratorios de Vigilancia e Investigación Epidemiológica, IMSS, 07760 Ciudad de México, Mexico.
Coordinación de Control Técnico e Insumos, IMSS, 07760 Ciudad de México, Mexico.
Microorganisms. 2021 Apr 15;9(4):850. doi: 10.3390/microorganisms9040850.
Until recently, the incidence of COVID-19 was primarily estimated using molecular diagnostic methods. However, the number of cases is vastly underreported using these methods. Seroprevalence studies estimate cumulative infection incidences and allow monitoring of transmission dynamics, and the presence of neutralizing antibodies in the population. In February 2020, the Mexican Social Security Institute began conducting anonymous unrelated sampling of residual sera from specimens across the country, excluding patients with fever within the previous two weeks and/or patients with an acute respiratory infection. Sampling was carried out weekly and began 17 days before Mexico's first officially confirmed case. The 24,273 sera obtained were analyzed by chemiluminescent-linked immunosorbent assay (CLIA) IgG S1/S2 and, later, positive cases using this technique were also analyzed to determine the rate of neutralization using the enzyme-linked immunosorbent assay (ELISA). We identified 40 CLIA IgG positive cases before the first official report of SARS-CoV-2 infection in Mexico. The national seroprevalence was 3.5% in February and 33.5% in December. Neutralizing activity among IgG positives patients during overall study period was 86.1%. The extent of the SARS-CoV-2 infection in Mexico is 21 times higher than that reported by molecular techniques. Although the general population is still far from achieving herd immunity, epidemiological indicators should be re-estimated based on serological studies of this type.
直到最近，新冠病毒病（COVID-19）的发病率主要是通过分子诊断方法来估计的。然而，使用这些方法报告的病例数被大幅低估。血清流行率研究可估计累积感染发病率，并有助于监测传播动态以及人群中中和抗体的存在情况。2020年2月，墨西哥社会保障局开始对来自全国各地标本的剩余血清进行匿名非关联抽样，排除前两周内有发热症状的患者和/或急性呼吸道感染患者。抽样每周进行一次，在墨西哥首例官方确诊病例出现前17天开始。对获得的24273份血清进行了化学发光免疫吸附测定（CLIA）IgG S1/S2分析，随后，对使用该技术检测出的阳性病例也进行了分析，以通过酶联免疫吸附测定（ELISA）确定中和率。在墨西哥首次官方报告严重急性呼吸综合征冠状病毒2（SARS-CoV-2）感染之前，我们鉴定出40例CLIA IgG阳性病例。2月份全国血清流行率为3.5%，12月份为33.5%。在整个研究期间，IgG阳性患者中的中和活性为86.1%。墨西哥SARS-CoV-2感染的程度比分子技术报告的高21倍。尽管普通人群仍远未实现群体免疫，但应基于此类血清学研究重新估计流行病学指标。
