Public Health Measures to Slow Community Spread of Coronavirus Disease 2019

Coronavirus disease 2019 was initially identified in an outbreak of viral pneumonia in Wuhan, People's Republic of China, in December 2019, and it has now been recognized in 77 countries with over 90 000 laboratoryconfirmed cases and over 3000 deaths as of March 3, 2020 The epidemiology of COVID-19 has recently become clearer as incident cases continue to rise and researchers refine estimates of the severity, transmissibility, and populations affected. Based on available data, COVID-19 is efficiently transmitted in the community, and the proportion of infections leading to severe illness is particularly high among adults 50 years of age and among individuals with comorbid health conditions. Although rare, severe cases have also been reported among younger individuals. Thus far, the estimated basic reproductive number of COVID-19 is higher than that of influenza 2, as is the case fatality risk for adults and older individuals.