Project

Discipline

infection disease dynamics; clinical epidemiology; sexually transmitted infections; chlamydia infections; prevention

Lead
Lay summary
This project is called EpideMMIC, which stands for 'Epidemiology and Mathematical Modelling for Infectious disease Control'. The overall aim of the project is to improve our understanding of how infectious diseases spread, and can be controlled. This project is a continuation of the EpideMMIC project, which began in May 2008. The principle is to obtain the best available epidemiological information that we can use to develop mathematical models to describe the transmission of infections and investigate how interventions work. We continue our work about Chlamydia trachomatis and extend it to other sexually transmitted infections. Our first objective is to determine how likely it is for C. trachomatis to be transmitted during an episode of unprotected heterosexual intercourse. Second, we will use medical records to help find out how soon a chlamydia infection can cause symptoms of complicated infection if it moves up into the fallopian tubes to cause pelvic inflammatory disease. Third, we will use information gained from our previous studies to find out which combinations of chlamydia screening, treatment, re-testing and partner notification can be most effective when targeted toward groups with lower and higher levels of sexual risk behaviour. Fourth, we will extend our models of C. trachomatis to investigate the potential for transmission and prevention of a newly identified sexually transmitted infection, Mycoplasma genitalium. Finally, we will investigate the potential effects that a new vaccine could have on transmission of C. trachomatis and prevention of pelvic inflammatory disease and infertility.  These studies will provide important information for patients, doctors, public health specialists and policy makers.

Direct link to Lay Summary

Last update: 21.02.2013

Active participation

Self-organised

Title	Year

Number	Title	Start	Funding scheme

Background: Sexually transmitted Chlamydia trachomatis is the most common notifiable condition in countries such as Switzerland, Sweden and the USA. Insights into the dynamics of existing and new sexually transmitted infections and robust information about the expected impact of feasible and achievable control interventions are urgently needed. Goals: The overall goal of the project is to integrate epidemiological expertise and mathematical modelling to improve the utility of modelling for public health decision making in two main areas: Objective 1. Improve parameter estimates in C. trachomatis infection transmission system. Objective 2. Predicting the effects of new and existing interventions. Methods of investigation: This project involves collaborations with several international researchers. For each objective we define one or more epidemiological datasets and corresponding mathematical modelling analysis and sensitivity analyses. Specific studies are: Objective 1.1 Determine the transmissibility of C. trachomatis per episode of unprotected heterosexual intercourse using prospective cohort data from young women and their partners with genotyping and chlamydia organism load data incorporated into a deterministic model; 1.2 Determine the relationship between lower genital tract C. trachomatis infection and clinical presentation of pelvic inflammatory disease based on case-control data about the time interval between new sexual partnerships and the onset of symptoms in women with chlamydial pelvic inflammatory disease or clinic attendance in those without; 2.1 To determine the most effective and achievable chlamydia screening strategies based on empirical data from four different interventions incorporated in a pair model; 2.2 To investigate the transmission dynamics and effects of screening for M. genitalium using prospective data about prevalence, persistence and pelvic inflammatory disease incidence in women with and without infection; 2.3 To investigate the potential effects of vaccination against C. trachomatis using data and model outputs from the earlier objectives in a pair model. Timescale: May 2011 to Apr 2014Importance and Impact: The proposed EpideMMIC project will consolidate earlier achievements in integration of epidemiology and mathematical modelling by a) increasing the robustness of model predictions about the effects real life of chlamydia screening and partner notification interventions, b) producing new insights into the effects of chlamydia infection and control and M. genitalium infection dynamics, and c) integrating the outputs of project components to investigate the potential effects of a future chlamydia vaccine. We have established the Swiss Meeting for Infectious Disease Dynamics (inaugural meeting at the University of Bern in May 2010), to establish a networking forum for infectious disease modellers in Switzerland and ensure that these projects and their outputs contribute to infection transmission science in Switzerland and internationally. The EpideMMIC project is particularly relevant in Switzerland now, as a new National Programme for HIV and sexually transmitted infections for 2011-2017 is being launched. The strategy recognises, for the first time, the importance of control strategies for sexually transmitted infections other than HIV.