Incidence study of Guillain-Barré syndrome in the province of Ferrara, Northern Italy, between 2003 and 2017. A 40-year follow-up

Background: Guillain-Barré syndrome (GBS) is an acute/subacute autoimmune inflammatory polyradiculoneuropathy. Previous epidemiological studies carried out in the province of Ferrara, Italy, from 1981 to 2002 indicated that GBS incidence had tendency of increase in the period considered. Objectives: We aimed at updating the epidemiology of GBS in the years 2003–2017 and carrying on the work started in the 1980s. Methods: We conducted an incidence study, by adopting a complete enumeration approach. Cases were identified from administrative, medical records, and database of the Ferrara Hospital and other provincial structures of the study area. Case ascertainment and definition are analogous to those adopted in previous surveys. Results: In the period 1 January 2003 to 31 December 2017, 73 patients living in the province of Ferrara (mean population 353,142) were found to be new cases of GBS fulfilling the NINCDS criteria. Male/female ratio 1.15. The mean incidence rate was 1.38 per 100,000 (95% CI 1.08–1.74), 1.54 per 100,000 for men and 1.23 per 100,000 for women, a nonsignificant difference. During the period considered, the rates had slow increase or mild decrease, without nonsignificant difference. The highest rates were observed for the age groups 70–79 years for both sexes. A half of patients reported infectious events in the weeks before the onset of symptoms. Conclusion: In line with many epidemiological data, in the whole period 2003–2017, we observed a trend towards increase or decrease in incidence and periods of relative stability. Similar temporal heterogeneity with the comparison to our previous works was found.