Incidence of Guillain-Barré syndrome in an Uruguayan population. A prospective cohort study.

Guillain-Barre syndrome (GBS) is an acute autoimmune peripheral inflammatory neuropathy and the most frequent cause of non-poliovirus acute flaccid paralysis worldwide. Background annual GBS incidence rates (IRs) in Latin America (LA) varies from 0.40 to 2.12/100000 persons per year. We performed a prospective population-based epidemiological study to determine the incidence and clinical profile of GBS in the most densely populated regions in Uruguay. The incidence of GBS in the population living in Montevideo and Canelones was studied in the period between June 01, 2018 and May 31, 2020. Patients older than 16 years of age diagnosed with GBS were prospectively enrolled. The mean global annual IR in the Uruguayan population was 1.7/100000 persons (95% CI 1.25-2.25). The highest rate was observed in the 65 to 74 age group among men (5.25/100000 per year) and in the 55 to 64 age group among women (2/100.000 per year). The mean age was 53.9 ± 19.5, years, without difference by sex (53.5 women, 54.5 men). The in-hospital mortality rate was 5.8%. A total of 51 patients were diagnosed with GBS: 42 (82%) had typical GBS, 5 (10%) Miller-Fisher syndrome (MFS), 3 (7%) a bilateral facial nerve palsy, 1 patient had a GBS-MFS overlap (2.3%). This is the first population-based GBS incidence study in LA using a prospective design. Our IR can be a useful tool in establishing the background rate to examine future disease trends caused by the introduction of new viruses or vaccines in Uruguay.