Estimating the Proportion of Coronavirus Disease 2019 Contacts Among Households based on Individuals with Myocardial Infarction History: a cross-sectional telephone survey.

Background Adults with cardiovascular diseases were disproportionately associated with a significantly increased risk of a severe form of COVID-19 and all-cause mortality. Objective The aim of this study was to report the associated symptoms for COVID-19 cases, to estimate the proportion of contacts and to describe the clinical signs and behaviors among individuals with/without myocardial infarction history among cases and contacts. Methods A two-week cross-sectional telephone survey was conducted during the first lock-down period in France, from 2020 May 4th to 15th. A total of 668 households participated representing 703 individuals with pre-existing cardiovascular disease in the past two years and 849 individuals without myocardial infarction history. Results High rates of compliance with health measures were self-reported, regardless of age or risk factors. Four confirmed COVID-19 cases were registered from four different households. Based on deductive assumptions, 9.73% were identified as contacts of whom 71.52% were asymptomatic. Among individuals with myocardial infarction history, two were COVID-19 cases, and the estimated proportion of contacts was 8.68% of whom 68.85% were asymptomatic. The cases and contacts presented different symptoms, with more respiratory signs. Conclusions The telephone survey could be a relevant tool for reporting the number of contacts on a limited period and territory, based on the presence of associated symptoms and COVID-19 cases in the households. This study advanced our knowledge to better prepare for future crises.