Increasing prevalence of multiple sclerosis in Buenos Aires, Argentina

In 1996, the prevalence of multiple sclerosis (MS) for the metropolitan area of Buenos Aires using the capture-recapture method was estimated to be between 14 and 19.8 cases per 100,000 inhabitants. The aim of this study was to update the prevalence to 2014 following the same methodology.

Gran Buenos Aires is the denomination that refers to the megalopolis comprised by the autonomous city of Buenos Aires and the surrounding conurbation of the province of Buenos Aires. The study was carried out taking December 2014 as the prevalence month. We used the capture-recapture method to estimate the prevalence of MS cross-matching registries from 6 MS Centers from the metropolitan area of Buenos Aires. Log-linear model Poisson regression was used to estimate the number of affected MS patients not detected by any of the 6 sources considered.

1035 registries were obtained from the 6 lists from 910 different patients detected. The population of the area based on 2010 census was 12,806,866, the number of MS cases estimated amongst source interactions were 4901. The estimated prevalence was 38.2 per 100,000 inhabitants (95% CI 36.1-41.2).

The study is an update almost 20 years after the first one in the area showing a significant increase in the previous reported prevalence. Our findings are in line with previous studies performed in other regions of the world.