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The impact of heterogeneity in contact structure on the spread of infectious diseases

Contact structure between individuals in a population has a large impact on the spread of an epidemic within this population. Many techniques and models are used to investigate this, from heterogeneous age-age mixing matrices to the use of network models in order to quantify the heterogeneity in the populations contacts. For many diseases, the probability of infection per contact, along with the exact contact structure are unknown, compounding the difficulty of identifying accurate contact structures. In this thesis, the impact that the contact structure has on the epidemic is examined in several different ways. Analytical expressions for the variance in the spread of an epidemic in its early exponential growth phase on heterogeneous networks are derived, showing that the third moment of the degree distribution is needed to fully specify this variance. This quantifies the impact that very well connected individuals can have on the early spread of an epidemic through a network. The dependency of the potential epidemic on the heterogeneity in workplace sizes and transmission rates is examined. It is shown that large workplaces can increase the expected size of the epidemic significantly, along with increasing the effectiveness of control strategies enacted during the early stages of an epidemic. In addition to this, a synthetic population is constructed for England and Wales from available datasets, in an attempt to model the spread of an epidemic through a realistic network of comparable size to the true population. The contact structure that is derived from this is compared with that taken from two surveys of contact structure in the same population, using simple models, and qualitative differences are seen to exist between the surveyed structures and the synthetic population structure.

Identiferoai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:640956
Date January 2014
CreatorsGraham, Matthew
PublisherUniversity of Warwick
Source SetsEthos UK
Detected LanguageEnglish
TypeElectronic Thesis or Dissertation
Sourcehttp://wrap.warwick.ac.uk/66543/

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