The epidemic of novel coronavirus (COVID-19) infections that began in China in late 2019 has rapidly grown and cases have been reported worldwide. An empirical estimate of the serial interval—the time from illness onset in a primary case (infector) to illness onset in a secondary case (infectee)—is needed to understand the turnover of case generations and transmissibility of the disease (Fine, 2003). Estimates of the serial interval can only be obtained by linking dates of onset for infector-infectee pairs, and these links are not easily established.
