Exploring the percentage of COVID-19 cases reported in the community in Canada and associated case fatality ratios  

作　　者：Brendan P.Dougherty Ben A.Smith Carolee A.Carson Nicholas H.Ogden 

机构地区：[1]Centre for Food-borne and Environmental Zoonotic Infectious Diseases,Public Health Agency of Canada,370 Speedvale Ave W.,Guelph,ON,N1H 7M7,Canada [2]Public Health Risk Sciences Division,National Microbiology Laboratory,Public Health Agency of Canada,370 Speedvale Ave W.,Guelph,ON,N1H 7M7,Canada [3]Public Health Risk Sciences Division,National Microbiology Laboratory,Public Health Agency of Canada,St.Hyacinthe,QC,J2S 2M2,Canada

出　　处：《Infectious Disease Modelling》2021年第1期123-132,共10页传染病建模（英文）

基　　金：This work was funded by the Public Health Agency of Canada.

摘　　要：While surveillance can identify changes in COVID-19 transmission patterns over time and space,sections of the population at risk,and the efficacy of public health measures,reported cases of COVID-19 are generally understood to only capture a subset of the actual number of cases.Our primary objective was to estimate the percentage of cases reported in the general community,considered as those that occurred outside of long-term care facilities(LTCFs),in specific provinces and Canada as a whole.We applied a methodology using the delay-adjusted case fatality ratio(CFR)to all cases and deaths,as well as those representing the general community.Our second objective was to assess whether the assumed CFR(mean=1.38%)was appropriate for calculating underestimation of cases in Canada.Estimates were developed for the period from March 11th,2020 to September 16th,2020.Estimates of the percentage of cases reported(PrCR)and CFR varied spatially and temporally across Canada.For the majority of provinces,and for Canada as a whole,the PrCR increased through the early stages of the pandemic.The estimated PrCR in general community settings for all of Canada increased from 18.1%to 69.0%throughout the entire study period.Estimates were greater when considering only those data from outside of LTCFs.The estimated upper bound CFR in general community settings for all of Canada decreased from 9.07%on March 11th,2020 to 2.00%on September 16th,2020.Therefore,the true CFR in the general community in Canada was likely less than 2%on September 16th.According to our analysis,some provinces,such as Alberta,Manitoba,Newfoundland and Labrador,Nova Scotia,and Saskatchewan reported a greater percentage of cases as of September 16th,compared to British Columbia,Ontario,and Quebec.This could be due to differences in testing rates and criteria,demographics,socioeconomic factors,race,and access to healthcare among the provinces.Further investigation into these factors could reveal differences among provinces that could partially explain the variation in

关 键 词：SARS-CoV-2 UNDERESTIMATION Coronavirus disease Long term care facilities Case fatality ratio 

分 类 号：R181.8[医药卫生—流行病学]