A study of the first 41 confirmed cases of COVID-19 published in January 2020 in The Lancet found that the earliest date of onset of symptoms was December 1, 2019.
Uchunguzi wa matukio 41 ya kwanza ya COVID-19 yaliyodhibitishwa, uliochapishwa mnamo Januari 2020 katika The Lancet, ulionyesha tarehe ya kwanza ambayo dalili zilianza ni 1 Desemba 2019.