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Updated: Oct 8, 2025
Dynamic Monitoring of Seroconversion using a Multianalyte Immunobead Assay for Covid-19
Published on: February 16, 2022
A cross sectional study found differential risks for COVID-19 seropositivity amongst health care professionals in
Marcela Zuñiga1, Anne J Lagomarcino2, Sergio Muñoz3
1Health Care Networks Under Secretariat, Ministry of Health, Monjitas 565, Santiago, Chile.
Objective:
Health care workers (HCWs) are at increased risk for SARS-CoV-2 infection, however not all face the same risk. We aimed to determine IgG/IgM prevalence and risk factors associated with seropositivity in Chilean HCWs.
Study Design And Setting:
This was a nationwide, cross-sectional study including a questionnaire and COVID-19 lateral flow IgG/IgM antibody testing. All HCWs in the Chilean public health care system were invited to participate following the country's first wave.
Results:
IgG/IgM positivity in 85,529 HCWs was 7.2%, ranging from 1.6% to 12.4% between regions. Additionally, 9.7% HCWs reported a positive PCR of which 47% were seropositive. Overall, 10,863 (12.7%) HCWs were PCR and/or IgG/IgM positive. Factors independently associated with increased odds ratios (ORs) for seropositivity were: working in a hospital, night shifts, contact with Covid-19, using public transport, male gender, age>45, BMI ≥30, and reporting ≥2 symptoms. Stress and/or mental health disorder and smoking were associated with decreased ORs. These factors remained significant when including PCR positive cases in the model.
Conclusions:
HCWs in the hospital were at highest risk for COVID-19, and several independent risk factors for seropositivity and/or PCR positivity were identified.
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