The reproduction number $R_t$ in structured and nonstructured populations

Using daily counts of newly infected individuals, Wallinga and Teunis (WT) introduced aconceptually simple method to estimate the number of secondary cases per primary case ($R_t$)for a given day. The method requires an estimate of the generation interval probability density function (pdf),which sp...

Full description

Saved in:
Bibliographic Details
Main Authors: Tom Burr, Gerardo Chowell
Format: Article
Language:English
Published: AIMS Press 2009-02-01
Series:Mathematical Biosciences and Engineering
Subjects:
Online Access:https://www.aimspress.com/article/doi/10.3934/mbe.2009.6.239
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1832590178414231552
author Tom Burr
Gerardo Chowell
author_facet Tom Burr
Gerardo Chowell
author_sort Tom Burr
collection DOAJ
description Using daily counts of newly infected individuals, Wallinga and Teunis (WT) introduced aconceptually simple method to estimate the number of secondary cases per primary case ($R_t$)for a given day. The method requires an estimate of the generation interval probability density function (pdf),which specifies the probabilities for the times between symptom onset in a primary case and symptom onset ina corresponding secondary case. Other methods to estimate $R_t$ arebased on explicit models such as the SIR model; therefore, onemight expect the WT method to be more robust to departures from SIR-type behavior.This paper uses simulated data to compare the quality of daily $R_t$ estimates based on a SIR model tothose using the WT method for both structured(classical SIR assumptions are violated) and nonstructured (classical SIR assumptions hold) populations.By using detailed simulations that record the infection day of each new infectionand the donor-recipient identities, the true $R_t$ and the generation interval pdf isknown with negligible error. We find that the generation interval pdf is timedependent in all cases, which agrees with recent results reported elsewhere.We also find that the WT method performs essentially the samein the structured populations (except for a spatial network) as it does in the nonstructured population. And,the WT method does as well or better than a SIR-model based method in three of the four structured populations.Therefore, even if the contact patterns are heterogeneous as in the structured populations evaluated here,the WT method provides reasonable estimates of $R_t$, as does the SIR method.
format Article
id doaj-art-39d4bed3b8b2473fbced0ffb0f468acb
institution Kabale University
issn 1551-0018
language English
publishDate 2009-02-01
publisher AIMS Press
record_format Article
series Mathematical Biosciences and Engineering
spelling doaj-art-39d4bed3b8b2473fbced0ffb0f468acb2025-01-24T01:59:06ZengAIMS PressMathematical Biosciences and Engineering1551-00182009-02-016223925910.3934/mbe.2009.6.239The reproduction number $R_t$ in structured and nonstructured populationsTom Burr0Gerardo Chowell1Statistical Sciences Group, Los Alamos National Laboratory, Los Alamos, NM 87545Statistical Sciences Group, Los Alamos National Laboratory, Los Alamos, NM 87545Using daily counts of newly infected individuals, Wallinga and Teunis (WT) introduced aconceptually simple method to estimate the number of secondary cases per primary case ($R_t$)for a given day. The method requires an estimate of the generation interval probability density function (pdf),which specifies the probabilities for the times between symptom onset in a primary case and symptom onset ina corresponding secondary case. Other methods to estimate $R_t$ arebased on explicit models such as the SIR model; therefore, onemight expect the WT method to be more robust to departures from SIR-type behavior.This paper uses simulated data to compare the quality of daily $R_t$ estimates based on a SIR model tothose using the WT method for both structured(classical SIR assumptions are violated) and nonstructured (classical SIR assumptions hold) populations.By using detailed simulations that record the infection day of each new infectionand the donor-recipient identities, the true $R_t$ and the generation interval pdf isknown with negligible error. We find that the generation interval pdf is timedependent in all cases, which agrees with recent results reported elsewhere.We also find that the WT method performs essentially the samein the structured populations (except for a spatial network) as it does in the nonstructured population. And,the WT method does as well or better than a SIR-model based method in three of the four structured populations.Therefore, even if the contact patterns are heterogeneous as in the structured populations evaluated here,the WT method provides reasonable estimates of $R_t$, as does the SIR method.https://www.aimspress.com/article/doi/10.3934/mbe.2009.6.239reproduction number; generation interval; structured population.
spellingShingle Tom Burr
Gerardo Chowell
The reproduction number $R_t$ in structured and nonstructured populations
Mathematical Biosciences and Engineering
reproduction number; generation interval; structured population.
title The reproduction number $R_t$ in structured and nonstructured populations
title_full The reproduction number $R_t$ in structured and nonstructured populations
title_fullStr The reproduction number $R_t$ in structured and nonstructured populations
title_full_unstemmed The reproduction number $R_t$ in structured and nonstructured populations
title_short The reproduction number $R_t$ in structured and nonstructured populations
title_sort reproduction number r t in structured and nonstructured populations
topic reproduction number; generation interval; structured population.
url https://www.aimspress.com/article/doi/10.3934/mbe.2009.6.239
work_keys_str_mv AT tomburr thereproductionnumberrtinstructuredandnonstructuredpopulations
AT gerardochowell thereproductionnumberrtinstructuredandnonstructuredpopulations
AT tomburr reproductionnumberrtinstructuredandnonstructuredpopulations
AT gerardochowell reproductionnumberrtinstructuredandnonstructuredpopulations