Maja Popovic1, Chiara Moccia2, Elena Isaevska2, Giovenale Moirano2, Costanza Pizzi2, Daniela Zugna2, Franca Rusconi3, Franco Merletti2, Milena Maule2, Lorenzo Richiardi2. 1. Cancer Epidemiology Unit, Department of Medical Sciences, University of Turin and Reference Centre for Epidemiology and Cancer Prevention in Piedmont (CPO Piemonte), Turin (Italy); maja.popovic@unito.it. 2. Cancer Epidemiology Unit, Department of Medical Sciences, University of Turin and Reference Centre for Epidemiology and Cancer Prevention in Piedmont (CPO Piemonte), Turin (Italy). 3. Unit of Epidemiology, Meyer Children's University Hospital, Florence (Italy).
Abstract
OBJECTIVES: to estimate the population prevalence of COVID-19-like symptoms in children and adults during the first SARS-CoV-2 epidemic wave hitting Italy in the spring 2020; to assess their geographical correlation with the cumulative number of COVID-19 cases by province; to analyse their clustering within families; to estimate their sensitivity, positive predictive value (PPV) and negative predictive value (NPV) for COVID-19 diagnosis in individuals tested for SARS-CoV-2. DESIGN: cross-sectional study nested within a birth cohort. SETTING AND PARTICIPANTS: mothers participating in an Italian birth cohort (NINFEA) were invited to complete an online questionnaire on COVID-19-like symptoms in their household. MAIN OUTCOME MEASURES: population prevalence of COVID-19-like symptoms in children and adults, geographical correlation of COVID-19-like symptoms with the cumulative number of COVID-19 cases by province, clustering of COVID-19-like symptoms within families, and sensitivity, PPV and NPV of COVID-19-like symptoms for COVID-19 diagnosis in individuals tested for SARS-CoV-2. RESULTS: information was collected on 3,184 households, 6,133 adults, and 5,751 children. In the period March-April 2020, 55.4% of the NINFEA families had at least one member with at least one COVID-19-like symptom. There was a strong geographical correlation between the population cumulative incidence of COVID-19 and the prevalence of muscle pain, fatigue, low-grade fever, and breathing difficulties in adults (Spearman's rho >=0.70). Having at least one family member with a COVID-19 diagnosis, compared with none tested for SARS-CoV-2, was associated with an increased prevalence ratio (PR) of almost all COVID-19-like symptoms in adults, and only of low-grade fever (37-37.5°C; PR 4.54; 95%CI 2.20-9.40) and anosmia/dysgeusia in children. Among adults with COVID-19 diagnosis, fatigue, muscle pain, and fever had a sensitivity >=70%. In individuals tested for SARS-CoV-2, with a 16.6% prevalence of COVID-19, breathing difficulties and nausea/vomiting had the highest PPVs, with point estimates close to 60%, and with NPVs close to 90%. CONCLUSIONS: the geographical prevalence of COVID-19-like symptoms in adults may inform on local disease clusters, while certain symptoms in family members of confirmed COVID-19 cases could help identify the intra-familial spread of the virus and its further propagation in the community. Low-grade fever is frequent in children with at least one household member with COVID-19 and possibly indicates child infection.
OBJECTIVES: to estimate the population prevalence of COVID-19-like symptoms in children and adults during the first SARS-CoV-2 epidemic wave hitting Italy in the spring 2020; to assess their geographical correlation with the cumulative number of COVID-19 cases by province; to analyse their clustering within families; to estimate their sensitivity, positive predictive value (PPV) and negative predictive value (NPV) for COVID-19 diagnosis in individuals tested for SARS-CoV-2. DESIGN: cross-sectional study nested within a birth cohort. SETTING AND PARTICIPANTS: mothers participating in an Italian birth cohort (NINFEA) were invited to complete an online questionnaire on COVID-19-like symptoms in their household. MAIN OUTCOME MEASURES: population prevalence of COVID-19-like symptoms in children and adults, geographical correlation of COVID-19-like symptoms with the cumulative number of COVID-19 cases by province, clustering of COVID-19-like symptoms within families, and sensitivity, PPV and NPV of COVID-19-like symptoms for COVID-19 diagnosis in individuals tested for SARS-CoV-2. RESULTS: information was collected on 3,184 households, 6,133 adults, and 5,751 children. In the period March-April 2020, 55.4% of the NINFEA families had at least one member with at least one COVID-19-like symptom. There was a strong geographical correlation between the population cumulative incidence of COVID-19 and the prevalence of muscle pain, fatigue, low-grade fever, and breathing difficulties in adults (Spearman's rho >=0.70). Having at least one family member with a COVID-19 diagnosis, compared with none tested for SARS-CoV-2, was associated with an increased prevalence ratio (PR) of almost all COVID-19-like symptoms in adults, and only of low-grade fever (37-37.5°C; PR 4.54; 95%CI 2.20-9.40) and anosmia/dysgeusia in children. Among adults with COVID-19 diagnosis, fatigue, muscle pain, and fever had a sensitivity >=70%. In individuals tested for SARS-CoV-2, with a 16.6% prevalence of COVID-19, breathing difficulties and nausea/vomiting had the highest PPVs, with point estimates close to 60%, and with NPVs close to 90%. CONCLUSIONS: the geographical prevalence of COVID-19-like symptoms in adults may inform on local disease clusters, while certain symptoms in family members of confirmed COVID-19 cases could help identify the intra-familial spread of the virus and its further propagation in the community. Low-grade fever is frequent in children with at least one household member with COVID-19 and possibly indicates child infection.