Research

Developing a realistic sexual network model of chlamydia transmission in Britain

Katherine ME Turner¹ , Elisabeth J Adams¹ , Nigel Gay¹ , Azra C Ghani² , Catherine Mercer³ and W John Edmunds¹

¹  Health Protection Agency, Centre for Infections, 61 Colindale Ave, Colindale, London, NW9 5EQ, UK

²  London School of Hygiene & Tropical Medicine, Keppel Street, London WC1E 7HT, UK

³  Department of Primary Care and Population Sciences, University College London, Mortimer Market Centre, Mortimer Market, London WC1E 6AU, UK

author email corresponding author email

Theoretical Biology and Medical Modelling 2006, 3:3doi:10.1186/1742-4682-3-3

Published:	20 January 2006

Abstract

Background

A national chlamydia screening programme is currently being rolled out in the UK and other countries. However, much of the epidemiology remains poorly understood. In this paper we present a stochastic, individual based, dynamic sexual network model of chlamydia transmission and its parameterisation. Mathematical models provide a theoretical framework for understanding the key epidemiological features of chlamydia: sexual behaviour, health care seeking and transmission dynamics.

Results

The model parameters were estimated either directly or by systematic fitting to a variety of appropriate data sources. The fitted model was representative of sexual behaviour, chlamydia epidemiology and health care use in England. We were able to recapture the observed age distribution of chlamydia prevalence.

Conclusion

Estimating parameters for models of sexual behaviour and transmission of chlamydia is complex. Most of the parameter values are highly correlated, highly variable and there is little empirical evidence to inform estimates. We used a novel approach to estimate the rate of active treatment seeking, by combining data sources, which improved the credibility of the model results. The model structure is flexible and is broadly applicable to other developed world settings and provides a practical tool for public health decision makers.