Multi-drug resistant tuberculosis in Finland—a forecast

Since the collapse of the Soviet system, travel between the St Petersburg district and the Baltic states and Finland has increased substantially. Although it is difficult to obtain exact figures on the number of cases of tuberculosis (TB) and multi-drug resistant (MDR) TB in these countries, there is strong evidence of growing epidemics, bringing added epidemiological threat to Finland. The purpose of this study is to produce a short-term “worst case” forecast of the spatial development of a threatened MDR-TB epidemic in Finland. The method applied is a chorological multistep procedure using statistical and geographical methods and a simulation technique. Instead of focusing on populations of carriers and susceptibles, emphasis is placed on identifying the primary influences directing the epidemic as a spatial process. This was done by dividing Finland into small-area units and by assigning the risk of obtaining MDR-TB to each unit based on socioeconomic and structural characteristics of the population. The simulated 6 year cumulative distribution of new MDR-TB cases showed a marked concentration of cases in the capital region and in a cluster of municipalities along the west coast. Although socioeconomic factors are important in explaining the distribution of cases, frequent and widespread international contacts seemed to be equally important at the beginning of the epidemic.