Multiple sclerosis prevalence in Malaga, Southern Spain estimated by the capture-recapture method.

Background: Although not definitively proven, there is commonly accepted to be a latitudinal gradient in the distribution of multiple sclerosis (MS), which is more frequent in temperate zones. The European Mediterranean countries are situated in a zone of median frequency, although ever increasing figures have been noted in the last decades. Objective: The objective of this study was to assess the current prevalence rate of MS in the province of Malaga, Southern Spain. Methods: The capture-recapture method (CRM) uses independent sources of data and permits the number of non-registered cases of a given disease to be estimated, and by doing so, to avoid ascertainment bias. Results: Use of this method showed the estimated prevalence rate of MS in the province of Malaga, Southern Spain, to be 125/10(5) (95% confidence interval: 102/10(5)-169/10(5)), higher than the figures published previously. Conclusions: Although we recognize that these data need to be confirmed in further studies and in other areas of the country using a similar method, we believe this study is the first to find such high figure of prevalence, being very similar to the figures reported in recent years in other southern European countries.