In recent years our understanding of infectious-disease epidemiology and control has been greatly increased through mathematical modelling. Insights from this increasingly-important, exciting field are now informing policy-making at the highest levels, and playing a growing role in research. The transmissible nature of infectious diseases makes them fundamentally different from non-infectious diseases, so techniques from 'classical' epidemiology are often invalid and hence lead to incorrect conclusions - not least in health-economic analysis.

Mathematical modelling now plays a key role in policy making, including health-economic aspects; emergency planning and risk assessment; control-programme evaluation; and monitoring of surveillance data. In research, it is essential in study design, analysis (including parameter estimation) and interpretation.

With infectious diseases frequently dominating news headlines, public health and pharmaceutical industry professionals, policy makers, and infectious disease researchers, increasingly need to understand the transmission patterns of infectious diseases, to be able to interpret and critically-evaluate both epidemiological data, and the findings of mathematical modelling studies. Recently there has been rapid progress in developing models and new techniques for measurement and analysis, which have been applied to outbreaks and emerging epidemics, such as SARS and avian influenza. A simple but powerful new technique for assessing the potential of different methods to control an infectious-disease outbreak was recently developed by course presenters.

Since 1990, this course has "demystified" mathematical modelling and kept public-health professionals, policy makers, and infectious disease researchers up-to-date with what they need to know about this fast-moving field, taught by individuals who are actively engaged in research and who advise leading public health professionals, policy-makers, governments, international organisations and pharmaceutical companies, both nationally and internationally, including on pandemic influenza, SARS, HIV, foot-and-mouth disease.

The Department of Infectious Disease Epidemiology, Imperial College London has been the world leader in mathematical modelling of the epidemiology and control of infectious diseases of humans and animals in both industrialised and developing countries for 20 years. It hosts the MRC Centre for Outbreak Analysis & Modelling, UNAIDS Epidemiology reference Group, Partnership for Child Development and the Gates Foundation-funded Schistosomiasis Control Initiative. This multi-disciplinary department has publishes frequently in Nature, Science, Lancet, PNAS, AIDS and other leading journals. It has developed models of avian influenza, SARS, HIV, TB, foot-and-mouth-disease, vector-borne diseases including malaria and dengue, helminth infections, childhood vaccine-preventable infections, sexually-transmitted infections, drug-resistant bacterial infections and others. Current studies involve the UK, Burkina Faso, Ecuador, Guatemala, India, Mali, Mexico, Netherlands, Niger, Peru, Russia, South Africa, Tanzania, Thailand, Uganda, USA, Venezuela, Zambia, and Zimbabwe.

Course participants require only a very basic mathematical ability, as the fundamental principles of infectious-disease transmission behaviour are simple to grasp. Nevertheless, they are very powerful and the clearer thinking they promote often leads to counter-intuitive insights, even just from a model diagram sketched on an envelope, or a simple model in Excel. However, misunderstanding of the key principles is common - and there are pitfalls to trap the unaware - so expert guidance is needed when learning.