Estimating unobserved SARS-CoV-2 infections in the United States

Alex Perkins; Sean M. Cavany; Sean M Moore; Rachel J Oidtman; Anita Lerch; Marya Poterek

is the (which was not peer-reviewed) The copyright holder for this preprint . https://doi.org/10.1101/2020.03. 15.20036582 doi: medRxiv preprint • Case reporting: The number of cases reported on day t was drawn from a binomial distribution with the number of trials equal to the number of infections with time of potential case reporting on day t, and the probability of success equal to the proportion of infections that are symptomatic. This accounts for the delay in reporting, but not underreporting, which is addressed below when we calculate the probability that a symptomatic infection is detected, ρ local . The time of potential case reporting was drawn from a gamma distribution of the period between symptom onset and case reporting with mean 6 days, and added to each infection's time of symptom onset. • Death: The number of deaths on day t was drawn from a binomial distribution with the number of trials equal to the number of infections that could have experienced death on day t, and the probability of success equal to the case fatality risk. The time of death was drawn from a log-normal distribution of time from symptom onset to death with mean 14 days (35), and added to each individual's time of symptom onset.