Secretaria Municipal de Saúde. Coordenadoria de Vigilância em Saúde.São Paulo, SP, Brasil.
Universidade de São Paulo. Faculdade de Saúde Pública. São Paulo, SP, Brasil.
Rev Saude Publica. 2021 Oct 22;55:62. doi: 10.11606/s1518-8787.2021055003970. eCollection 2021.
To estimate the evolution of the prevalence of SARS-CoV-2 virus infection among residents aged 18 years or over in the municipality of São Paulo.
This is a population-based household survey conducted every 15 days, between June and September 2020, and January and February 2021. In total, the study comprised 11 phases. The presence of antibodies against SARS-CoV-2 was identified in venous blood using a lateral flow test, Wondfo Biotech. In the last phase, the researchers combined it with an immunoenzymatic test, Euroimmun. The participants also answered a semi-structured questionnaire on sociodemographic and economic factors, and on social distancing measures. Prevalence estimates and the 95% confidence interval were estimated according to regions, Human Development Index, sex, age group, ethnicity, education, income, and variables associated with risk or prevention of infection. To compare the frequencies among the categories of each variable, the chi-square test with Rao-Scott correction was used, considering a significance level of 5%.
In total, 23,397 individuals were interviewed and had their samples collected. The estimated prevalence of antibodies against SARS-CoV-2 ranged from 9.7% (95%CI: 7.9-11.8%) to 25.0% (95%CI: 21.7-28.7). The prevalence of individuals with antibodies against the virus was higher among black and brown people, people with lower schooling and income, and among residents of regions with lower Human Development Index. The lowest prevalences were associated with recommended measures of disease protection. The proportion of asymptomatic infection was 45.1%.
The estimated prevalence of the infection was lower than the cumulative incidence variation, except for the last phase of the study. The differences in prevalence estimates observed among subpopulations showed social inequality as a risk of infection. The lower prevalence observed among those who could follow prevention measures reinforce the need to maintain social distancing measures as a way to prevent SARS-CoV-2 infection.
估计 18 岁及以上圣保罗市居民中 SARS-CoV-2 病毒感染的流行率演变情况。
这是一项基于人群的家庭调查，于 2020 年 6 月至 9 月和 2021 年 1 月至 2 月期间每 15 天进行一次。该研究共包括 11 个阶段。使用侧向流动试验（Wondfo Biotech）在静脉血中检测 SARS-CoV-2 抗体的存在。在最后一个阶段，研究人员将其与免疫酶试验（Euroimmun）相结合。参与者还回答了一个关于社会人口经济学因素和社会隔离措施的半结构化问卷。根据地区、人类发展指数、性别、年龄组、种族、教育、收入以及与感染风险或预防相关的变量，估计了流行率估计值和 95%置信区间。为了比较每个变量类别之间的频率，使用了具有 Rao-Scott 校正的卡方检验，置信水平为 5%。
共采访了 23397 人并采集了样本。估计的 SARS-CoV-2 抗体流行率范围为 9.7%（95%CI：7.9-11.8%）至 25.0%（95%CI：21.7-28.7%）。病毒抗体阳性者中，黑人和棕色人种、受教育程度和收入较低的人群以及人类发展指数较低地区的居民的患病率较高。与疾病保护推荐措施相关的最低患病率。无症状感染的比例为 45.1%。
除研究的最后阶段外，估计的感染流行率低于累积发病率的变化。观察到的亚人群之间的流行率估计差异表明，社会不平等是感染的风险因素。在能够遵循预防措施的人群中观察到的较低流行率，强调了保持社会距离措施作为预防 SARS-CoV-2 感染的一种方式的重要性。
