Incidence of Guillain-Barré syndrome in Chile: a population-based study.

The Guillain-Barré syndrome (GBS) incidence rate (IR) varies between 0.16 and 3.00 cases per 100,000 inhabitants. Little data exist on the epidemiology of GBS in Latin American countries. Our objective was to describe GBS epidemiology based on a national database in a Latin American country and to contribute to the global map of GBS epidemiology. This was a retrospective study that included all reported GBS cases in Chile between 2001 and 2012. Gender, age, seasonal occurrence, and geographical distribution were analyzed. A total of 4,158 GBS cases were identified from 19,513,655 registries. The mean age was 37 ± 24 years, and 59% of patients were male (male to female ratio of 1.5 : 1). Gender IR was 2.53/100,000 for males and 1.68/100,000 for females. The overall standardized IR was 2.1/100,000, although this varied between 1.61/100,000 (2001) and 2.35/100,000 (2010). The seasonal distribution was as follows: autumn 22%; winter 25%; spring 27%; and summer 26%. The geographical IR were as follows: far North 1.49/100,000; North 1.94/100,000; Central 1.97/100,000; South 3.18/100,000; and far South 2.78/100,000. The reported IR of GBS in Chile was similar to other studies based on national databases. In Chile, IR was greater in men and in the south.