The Incidence of Guillain-Barre Syndrome in Ferrara, Italy: is the Disease Really Increasing?

The Guillain-Barre syndrome (GBS) incidence has been updated in the area of the Local Health District of Ferrara, Unita Sanitaria Locale n. 31 (USL 31), Northern Italy, (where a previous survey found an average annual incidence of 1.26/10000 population) in order to verify a supposed increase in GBS occurrence. The updated mean annual incidence over the years from 1981 to 1993 (average resident population: 177235 inhabitants) was 1.87/100000 population (1.66/100000 when age-adjusted). The rate increased progressively in the four subsequent time intervals into which the study period was subdivided (from 1.09/100000 in the years 1981-1984 to 2.73/100000 in the years 1991-1993) with a significant temporal variation (0.025 <p <0.05). The incidence was higher in the urban centres than in the rural zone of USL 31 (2.22/100000 and 1.10/100000; 0.025 <p <0.05) and an increase of GBS risk in the urban area was found. The incidence showed an increase in the oldest age groups of the study population. These findings seem to confirm a slight increase of GBS risk in the area of Ferrara with particular reference to urban centres and elderly people.