Community Memory of COVID-19 Infections Post Lockdown as a Surrogate for Incubation Time

Meher K Prakash

In designing non-pharmaceutical interventions such as quarantine measures, it is important to know how long an individual can potentially remain infected and infectious. [1] The incubation time of an infectious disease is the duration between the exposure to an infected individual and the appearance of the symptoms. [2, 3] The incubation times for several acute respiratory infections have been measured [4] assuming their distributions. [5] These incubation times range from a couple of days to about 2 weeks. [4] In the studies of the COVID-19 pandemic, incubations lasting 2 to 14 days [6] , and reports suggesting up to 19 days [7] or even 24 days [8] have been observed with median incubation times of around 5.1 days [9] to 5.8 days [10] . At the heart of the estimation of the incubation period is an efficient contact tracing. The symptomatic individuals history is traced back to the possible day of exposure to infected individuals. As rigorous as this procedure is, by its nature it is not easily scalable as the collecting the exposure histories of hundreds of individuals may not be easy. This problem is even more complicated in the COVID-19 infections, as a very large fraction of the infections have been passed on by asymptomatic individuals. Further, the number of patients studied is also limited, which makes the likelihood of the errors in the "tail regions" of the distribution much higher.