Introducing the outbreak threshold in epidemiology.

When a pathogen is rare in a host population, there is a chance that it will die out because of stochastic effects instead of causing a major epidemic. Yet no criteria exist to determine when the pathogen increases to a risky level, from which it has a large chance of dying out, to when a major outb...

Full description

Bibliographic Details
Main Authors: Matthew Hartfield, Samuel Alizon
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2013-01-01
Series:PLoS Pathogens
Online Access:https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/23785276/pdf/?tool=EBI
_version_ 1831585086377558016
author Matthew Hartfield
Samuel Alizon
author_facet Matthew Hartfield
Samuel Alizon
author_sort Matthew Hartfield
collection DOAJ
description When a pathogen is rare in a host population, there is a chance that it will die out because of stochastic effects instead of causing a major epidemic. Yet no criteria exist to determine when the pathogen increases to a risky level, from which it has a large chance of dying out, to when a major outbreak is almost certain. We introduce such an outbreak threshold (T₀), and find that for large and homogeneous host populations, in which the pathogen has a reproductive ratio R₀, on the order of 1/Log(R₀) infected individuals are needed to prevent stochastic fade-out during the early stages of an epidemic. We also show how this threshold scales with higher heterogeneity and R0 in the host population. These results have implications for controlling emerging and re-emerging pathogens.
first_indexed 2024-12-17T21:12:28Z
format Article
id doaj.art-dd510a917f0a4be4a7d6517f34b64b99
institution Directory Open Access Journal
issn 1553-7366
1553-7374
language English
last_indexed 2024-12-17T21:12:28Z
publishDate 2013-01-01
publisher Public Library of Science (PLoS)
record_format Article
series PLoS Pathogens
spelling doaj.art-dd510a917f0a4be4a7d6517f34b64b992022-12-21T21:32:26ZengPublic Library of Science (PLoS)PLoS Pathogens1553-73661553-73742013-01-0196e100327710.1371/journal.ppat.1003277Introducing the outbreak threshold in epidemiology.Matthew HartfieldSamuel AlizonWhen a pathogen is rare in a host population, there is a chance that it will die out because of stochastic effects instead of causing a major epidemic. Yet no criteria exist to determine when the pathogen increases to a risky level, from which it has a large chance of dying out, to when a major outbreak is almost certain. We introduce such an outbreak threshold (T₀), and find that for large and homogeneous host populations, in which the pathogen has a reproductive ratio R₀, on the order of 1/Log(R₀) infected individuals are needed to prevent stochastic fade-out during the early stages of an epidemic. We also show how this threshold scales with higher heterogeneity and R0 in the host population. These results have implications for controlling emerging and re-emerging pathogens.https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/23785276/pdf/?tool=EBI
spellingShingle Matthew Hartfield
Samuel Alizon
Introducing the outbreak threshold in epidemiology.
PLoS Pathogens
title Introducing the outbreak threshold in epidemiology.
title_full Introducing the outbreak threshold in epidemiology.
title_fullStr Introducing the outbreak threshold in epidemiology.
title_full_unstemmed Introducing the outbreak threshold in epidemiology.
title_short Introducing the outbreak threshold in epidemiology.
title_sort introducing the outbreak threshold in epidemiology
url https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/23785276/pdf/?tool=EBI
work_keys_str_mv AT matthewhartfield introducingtheoutbreakthresholdinepidemiology
AT samuelalizon introducingtheoutbreakthresholdinepidemiology