Novel coronavirus 2019-nCoV: early estimation of epidemiological parameters and epidemic predictions

Jonathan M Read; Jessica RE Bridgen; Derek AT Cummings; Antonia Ho; Chris P Jewell

A comparison of the efficiency of transmission in this outbreak and in SARS outbreaks can be seen as well in simple comparisons of doubling times in each outbreak. In SARS, doubling times varied from 4.6 days to 14.2 days depending on setting (doubling time, Td=6.0 (1358 over 63 days, Singapore), Td=4.6 (425 over 41 days, Hong Kong), Td=14.2 (7919 over 185 days, overall)) (Lipsitch et al., 2003) . Using confirmed case information (41 reported January 14; 291 reported 24:00 on January 20; 1975 reported 24:00 on January 25)(NHCPRC daily reports, 2020) we find doubling times of 2.1, 1.8, and 2.0 days. If the outbreak has been ongoing for a longer period of time, this would increase the estimated doubling time. These doubling time estimates, similar to our estimates of 0 , are susceptible to bias due to the dynamics of case reporting, with bunching of identified cases (due to temporally clustered recognition of cases) tending to bias our estimate towards lower doubling times. We note our estimates of the doubling time in this outbreak are short compared to estimates from the SARS outbreak in Hong Kong (Lipsitch et al., 2003) .