Growth models and the HIV epidemic in Finland

Today, we know a lot about HIV and AIDS, yet too little to be able to stop the pandemic by a vaccination or by medication. Until that day is at hand, the only means of controlling the pandemic is by information--information about the diffusion of the virus, about risk behaviour, about safe sex, and about social responsibility. Educating people must be based on concise clinical experience, an up-to-date picture of the epidemiological situation, and reliable forecasts about the future course of the epidemic. Producing reliable forecasts about the HIV epidemic has proved to be a more complicated task than expected. The proven, reliable, and in most cases very useful epidemiological models have been far from successful when applied to the HIV epidemic. The reason for this is mostly due to the lack of reliable data depicting the true HIV seroprevalence. Instead of being handicapped by the problems of inadequate data, geographical modelling of the HIV epidemic is able to rely on its theoretical understanding and good knowledge about the spatial organization and the functioning of societies to make its forecasts. Due to its flexibility of approach, geographical modelling can adjust itself to less accurate data, thus providing an interim forecasting instrument until epidemiological modelling becomes successful. This paper presents the results of an analysis of the HIV epidemic in Finland based on cartographic analysis of municipal data and the use of a simple growth model.