Super-spreaders and the rate of transmission of the SARS virus

Michael Small, Chi Kong Tse, David M. Walker

Research output: Journal article publicationJournal articleAcademic researchpeer-review

67 Citations (Scopus)

Abstract

We describe a stochastic small-world network model of transmission of the SARS virus. Unlike the standard Susceptible-Infected-Removed models of disease transmission, our model exhibits both geographically localised outbreaks and "super-spreaders". Moreover, the combination of localised and long range links allows for more accurate modelling of partial isolation and various public health policies. From this model, we derive an expression for the probability of a widespread outbreak and a condition to ensure that the epidemic is controlled. Moreover, multiple simulations are used to make predictions of the likelihood of various eventual scenarios for fixed initial conditions. The main conclusions of this study are: (i) "super-spreaders" may occur even if the infectiousness of all infected individuals is constant; (ii) consistent with previous reports, extended exposure time beyond 3-5 days (i.e. significant nosocomial transmission) was the key factor in the severity of the SARS outbreak in Hong Kong; and, (iii) the spread of SARS can be effectively controlled by either limiting long range links (imposing a partial quarantine) or enforcing rapid hospitalisation and isolation of symptomatic individuals.
Original languageEnglish
Pages (from-to)146-158
Number of pages13
JournalPhysica D: Nonlinear Phenomena
Volume215
Issue number2
DOIs
Publication statusPublished - 15 Mar 2006

Keywords

  • Severe Acute Respiratory Syndrome (SARS)
  • Small-world network
  • Super-spreader event
  • Transmission dynamics

ASJC Scopus subject areas

  • Applied Mathematics
  • Statistical and Nonlinear Physics

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