Estimating the infection and case fatality ratio for COVID-19 using age-adjusted data from the outbreak on the Diamond Princess cruise ship

Timothy W Russell; Joel Hellewell; Christopher I Jarvis; Kevin van-Zandvoort; Sam Abbott; Ruwan Ratnayake; Stefan Flasche; Rosalind M Eggo; Adam J Kucharski

Using the age-stratified nCFR estimates reported in a large study in China [7] , we then calculated the expected number of deaths of people who were onboard the ship in each age group, assuming this nCFR estimate was accurate. This produced a total of 15.15 expected deaths, which gives a nCFR estimate of 5% (15.15/301) for Diamond Princess (Table 2) , which falls within the top end of our 95% CI. As our corrected cCFR for Diamond Princess was 2.3% (0.75% -5.3%), this suggests we need to multiply the nCFR estimates in China [7] by a factor 46% (95% CI: 15-105%) to obtain the correct value. As the raw overall nCFR reported in the China data was 2.3% [7] , this suggests the cCFR in China during that period was 1.1% (95% CI: 0.3-2.4%) and the IFR was 0.5% (95% CI: 0.2-1.2%). Based on cases and deaths reported in China up to . CC-BY 4.0 International license It is made available under a author/funder, who has granted medRxiv a license to display the preprint in perpetuity.