Seroprevalence of COVID-19 in Carabayllo Peru

Objectives: To measure the SARS-CoV-2 seroprevalence in the Carabayllo
district of Lima, Peru at the end of the first wave of the pandemic.
Methods: This was a cross-sectional study of the district with random
bi-stage cluster sampling. We collected socio-demographic and clinical
data as well as serum samples for SARS-CoV2 antibody testing. Results:
Among 2,014 subjects sampled, 59.93% were men. SAR-CoV-2 seropositivity
was 24.88% (501/2014), and after adjusting for the sampling design effects
and test performance, the seroprevalence in November/December 2020 was
22.4% (95% CI 22.35 - 27.63). Seropositivity varied by age, with
participants aged 30-59 years old having the highest prevalence.
Seropositivity in symptomatic patients (32%) was 1.5 times more than in
asymptomatic ones (23%), and work away of home, age >18, COVID-19
home contact, obesity were risk factors of SARS-CoV-2. Conclusions: The
low seroprevalence after the first wave of pandemic in this community
indicates that a high proportion of people remained susceptible. Infection
was important among people who never reported symptoms. People with
obesity had a higher risk of having SARS-Cov-2 infection.

研究目的：测定秘鲁利马省卡拉巴约区在新冠疫情第一波末期的严重急性呼吸综合征冠状病毒2（SARS-CoV-2）血清阳性率。研究方法：本研究针对该地区开展两阶段整群随机抽样的横断面研究，收集了社会人口学资料、临床数据以及用于SARS-CoV-2抗体检测的血清样本。研究结果：本次共纳入2014名抽样研究对象，其中59.93%为男性。SARS-CoV-2血清阳性率为24.88%（501/2014）；经抽样设计效应与检测性能校正后，2020年11月至12月的血清阳性率为22.4%（95%置信区间22.35~27.63）。血清阳性率存在年龄差异，30~59岁年龄段人群的阳性率最高。有症状患者的血清阳性率（32%）为无症状患者（23%）的1.5倍；外出务工、年龄＞18岁、居家接触新冠感染者、肥胖均为SARS-CoV-2感染的危险因素。研究结论：该社区在疫情第一波过后血清阳性率偏低，提示仍有较高比例的人群易感。未报告症状的感染者占比可观，肥胖人群感染SARS-CoV-2的风险更高。