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Estimating the SARS-CoV-2 infected population fraction and the infection-to-fatality ratio: A data-driven case study based on Swedish time series data

Wacker, Andreas LU orcid ; Jöud, Anna LU orcid ; Bernhardsson, Bo LU orcid ; Gerlee, Philip ; Soltesz, Kristian LU orcid and Gustafsson, Fredrik (2021) In Scientific Reports 11(23963). p.1-11
Abstract
We demonstrate that finite impulse response (FIR) models can be applied to analyze the time evolution of an epidemic with its impact on deaths and healthcare strain. Using time series data for COVID-19-related cases, ICU admissions and deaths from Sweden, the FIR model gives a consistent epidemiological trajectory for a simple delta filter function. This results in a consistent scaling between the time series if appropriate time delays are applied and allows the reconstruction of cases for times before July 2020, when RT-PCR testing was not widely available. Combined with randomized RT-PCR study results, we utilize this approach to estimate the total number of infections in Sweden, and the corresponding infection-to-fatality ratio (IFR),... (More)
We demonstrate that finite impulse response (FIR) models can be applied to analyze the time evolution of an epidemic with its impact on deaths and healthcare strain. Using time series data for COVID-19-related cases, ICU admissions and deaths from Sweden, the FIR model gives a consistent epidemiological trajectory for a simple delta filter function. This results in a consistent scaling between the time series if appropriate time delays are applied and allows the reconstruction of cases for times before July 2020, when RT-PCR testing was not widely available. Combined with randomized RT-PCR study results, we utilize this approach to estimate the total number of infections in Sweden, and the corresponding infection-to-fatality ratio (IFR), infection-to-case ratio (ICR), and infection-to-ICU admission ratio (IIAR). Our values for IFR, ICR and IIAR are essentially constant over large parts of 2020 in contrast with claims of healthcare adaptation or mutated virus variants importantly affecting these ratios. We observe a diminished IFR in late summer 2020 as well as a strong decline during 2021, following the launch of a nation-wide vaccination program. The total number of infections during 2020 is estimated to 1.3 million, indicating that Sweden was far from herd immunity. (Less)
Please use this url to cite or link to this publication:
author
; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Scientific Reports
volume
11
issue
23963
pages
1 - 11
publisher
Nature Publishing Group
external identifiers
  • scopus:85121309183
  • pmid:34907208
ISSN
2045-2322
DOI
10.1038/s41598-021-03269-w
project
COVID-19: Dynamical modelling for estimation and prediction
language
English
LU publication?
yes
id
70802d45-fab6-4897-a88c-3c4bd69a1f30
alternative location
https://rdcu.be/cDbSH
date added to LUP
2021-11-24 13:47:31
date last changed
2023-12-01 14:34:19
@article{70802d45-fab6-4897-a88c-3c4bd69a1f30,
  abstract     = {{We demonstrate that finite impulse response (FIR) models can be applied to analyze the time evolution of an epidemic with its impact on deaths and healthcare strain. Using time series data for COVID-19-related cases, ICU admissions and deaths from Sweden, the FIR model gives a consistent epidemiological trajectory for a simple delta filter function. This results in a consistent scaling between the time series if appropriate time delays are applied and allows the reconstruction of cases for times before July 2020, when RT-PCR testing was not widely available. Combined with randomized RT-PCR study results, we utilize this approach to estimate the total number of infections in Sweden, and the corresponding infection-to-fatality ratio (IFR), infection-to-case ratio (ICR), and infection-to-ICU admission ratio (IIAR). Our values for IFR, ICR and IIAR are essentially constant over large parts of 2020 in contrast with claims of healthcare adaptation or mutated virus variants importantly affecting these ratios. We observe a diminished IFR in late summer 2020 as well as a strong decline during 2021, following the launch of a nation-wide vaccination program. The total number of infections during 2020 is estimated to 1.3 million, indicating that Sweden was far from herd immunity.}},
  author       = {{Wacker, Andreas and Jöud, Anna and Bernhardsson, Bo and Gerlee, Philip and Soltesz, Kristian and Gustafsson, Fredrik}},
  issn         = {{2045-2322}},
  language     = {{eng}},
  number       = {{23963}},
  pages        = {{1--11}},
  publisher    = {{Nature Publishing Group}},
  series       = {{Scientific Reports}},
  title        = {{Estimating the SARS-CoV-2 infected population fraction and the infection-to-fatality ratio: A data-driven case study based on Swedish time series data}},
  url          = {{http://dx.doi.org/10.1038/s41598-021-03269-w}},
  doi          = {{10.1038/s41598-021-03269-w}},
  volume       = {{11}},
  year         = {{2021}},
}