COVID-19-like symptoms and their relation to the SARS-CoV-2 epidemic in children and adults of an Italian birth cohort

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.

Factors associated with self-perceived knowledge of COVID-19: a study among women from the NINFEA birth cohort.

BACKGROUND: health literacy may contribute to the strategies to control the Coronavirus disease 2019 (COVID-19), as individuals need to acquire promptly new health information, understand the reasons behind recommendations, and adapt their behaviour accordingly. OBJECTIVES: to investigate sociodemographic and disease-related factors that can influence self-perceived knowledge (poor/medium vs high) about COVID-19 in women of the Italian NINFEA birth cohort. DESIGN: cross-sectional study. SETTING AND PARTICIPANTS: a web-based anonymous survey on COVID-19 was sent in April 2020 to women participating in the NINFEA cohort. A total of 3,129 women were included in the study. MAIN OUTCOME MEASURES: using multiple weighted logistic regression models, self-perceived knowledge level was analysed in relation with the following variables: age, education level, family size, cumulative incidence of severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2) cases until 7 April 2020 by province, presence of COVID-19-like symptoms, SARS-CoV-2 testing, and COVID-19 diagnosis. RESULTS: the prevalence of self-perceived poor/medium knowledge was 57%. In multivariable logistic regression analyses, the odds ratio (OR) of self-perceived poor/medium COVID-19 knowledge level was increased for low/medium compared with high education level (OR 1.57; 95%CI 1.34-1.84), and decreased for SARS-CoV-2 testing (OR 0.25; 95%CI 0.16-0.39) and COVID-19 diagnosis (OR 0.20; 95%CI 0.07-0.60). There was no evidence of association between the other analysed variables and self-perceived knowledge level. CONCLUSIONS: the findings of this study suggest that low educational level is a determinant of low self-perceived knowledge on COVID-19 in middle-aged women.