The effect of public health interventions on the spread of influenza among cities

Abstract

Infectiousdiseaseisnolongeralocalproblem.Modernpopulationsaremoremobilethaneverbefore,andwiththismobilitycomesactiveglobalmixingofinfectiousdisease.Tounderstandthespreadofdiseasessuchasinfluenza,weuseamulti-cityepidemicmodel.WeextendtheSEIR(susceptible-exposed-infectious-recovered)modeltoincorporatepopulationmigrationbetweencities,andusethismodeltoanalyzethegeographicspreadofinfluenza.Weinvestigatetheeffectivenessoftravelrestrictionsasacontrolagainstthespreadofinfluenza.

Firstweobtainthebasicreproductionnumberforthesinglecitycase,andobservetwoothercontrolstrategiessuggestedbythiscase:increasingthenumberofclinicallyillindividualsthataretreated,andreducingtheintervalbetweeninfectionandtreatmentofsuchindividuals.

Weevaluatetheeffectivenessofthethreecontrolstrategieswithnumericalsimulations.Itisshownthattravelrestrictionsarelesseffectivethantheothertwostrategies.Ingeneral,travelrestrictiontendstodelaythespreadofthediseaseintonewcities.However,itcanincreasethepeakheightofinfectedpopulationsinallcities.Anunderstandingoftheepidemiologicalstructuresofrelatedcitiesisstronglyrecommendedinordertoeffectivelyapplythetravelrestrictionstrategy.