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Humanized Mouse Model to Study Bacterial Infections Targeting the Microvasculature
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Meningitis, pathogenicity near criticality: the epidemiology of meningococcal disease as a model for accidental

Nico Stollenwerk1, Vincent A A Jansen

  • 1School of Biological Sciences, Royal Holloway, University of London, Egham, Surrey TW20 0EX, UK. nks22@cam.ac.uk

Journal of Theoretical Biology
|May 7, 2003
PubMed

Insights

Harmless and pathogenic microbes competing can lead to frequent pathogenic outbreaks. Our model shows this can cause clustered outbreaks, even with low pathogenicity, mirroring severe diseases like meningitis.

Area of Science:

  • Epidemiology
  • Mathematical Biology
  • Infectious Disease Modeling

Background:

  • Asymptomatic carriers play a crucial role in infectious disease transmission.
  • The competition between harmless and pathogenic strains of an agent can influence disease dynamics.
  • Understanding outbreak patterns is key to managing public health threats.

Purpose of the Study:

  • To develop and analyze a mathematical model for infectious diseases transmitted by asymptomatic carriers.
  • To investigate the conditions under which frequent outbreaks of pathogenic strains occur.
  • To explore the relationship between pathogenicity, outbreak clustering, and critical phenomena.

Main Methods:

  • Formulation of a Susceptible-Infected-Recovered (SIR) epidemic model incorporating a mutant strain (SIRYX).
  • Analysis using a master equation framework to describe the full system dynamics.
  • Investigation of limiting cases and analytical demonstration of power law scaling near criticality.

Main Results:

  • The model predicts frequent outbreaks of pathogenic strains when competing with harmless strains.
  • A high number of clustered outbreaks at low pathogenicity was observed, consistent with real-world data (e.g., meningitis).
  • Analytical results show convergence to power law scaling and divergence of outbreak variance near criticality.

Conclusions:

  • The model provides a novel explanation for large fluctuations in outbreaks of opportunistic pathogens.
  • Findings suggest that seemingly harmless commensal organisms can evolve into dangerous pathogens.
  • The study offers insights for future epidemiological strategies, particularly for diseases like meningococcal disease.

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