Please use this identifier to cite or link to this item:http://hdl.handle.net/20.500.12105/14323
ENE-COVID nationwide serosurvey served to characterize asymptomatic infections and to develop a symptom-based risk score to predict COVID-19
Perez-Gomez, Beatriz ISCIII | Pastor-Barriuso, Roberto ISCIII | Perez-Olmeda, Mayte ISCIII | Hernán, Miguel A | Oteo-Iglesias, Jesus ISCIII | Fernandez de Larrea-Baz, Nerea ISCIII | Fernandez-Garcia, Aurora ISCIII | Martín, Mariano | Fernandez-Navarro, Pablo L ISCIII | Cruz, Israel ISCIII | Sanmartín, Jose L | Paniagua-Caparros, Jose Leon ISCIII | Muñoz-Montalvo, Juan F | Blanco, Faustino | Yotti-Alvarez, Raquel ISCIII | Pollan-Santamaria, Marina ISCIII | ENE-COVID Study Group
J Clin Epidemiol. 2021 Nov;139:240-254.
Objectives: To characterize asymptomatic SARS-CoV-2 infections and develop a symptom-based risk score useful in primary healthcare. Study design and setting: Sixty-one thousand ninty-two community-dwelling participants in a nationwide population-based serosurvey completed a questionnaire on COVID-19 symptoms and received an immunoassay for SARS-CoV-2 IgG antibodies between April 27 and June 22, 2020. Standardized prevalence ratios for asymptomatic infection were estimated across participant characteristics. We constructed a symptom-based risk score and evaluated its ability to predict SARS-CoV-2 infection. Results: Of all, 28.7% of infections were asymptomatic (95% CI 26.1-31.4%). Standardized asymptomatic prevalence ratios were 1.19 (1.02-1.40) for men vs. women, 1.82 (1.33-2.50) and 1.45 (0.96-2.18) for individuals <20 and ≥80 years vs. those aged 40-59, 1.27 (1.03-1.55) for smokers vs. nonsmokers, and 1.91 (1.59-2.29) for individuals without vs. with case contact. In symptomatic population, a symptom-based score (weights: severe tiredness = 1; absence of sore throat = 1; fever = 2; anosmia/ageusia = 5) reached standardized seroprevalence ratio of 8.71 (7.37-10.3), discrimination index of 0.79 (0.77-0.81), and sensitivity and specificity of 71.4% (68.1-74.4%) and 74.2% (73.1-75.2%) for a score ≥3. Conclusion: The presence of anosmia/ageusia, fever with severe tiredness, or fever without sore throat should serve to suspect COVID-19 in areas with active viral circulation. The proportion of asymptomatics in children and adolescents challenges infection control.
COVID-19 | General population | Nationwide serosurvey | Prediction model | SARS-CoV-2 infection | Symptoms