Guillain-Barré syndrome: an Italian multicentre case-control study. Guillain-Barré Syndrome Study Group.

Various diseases are described as antecedents of Guillain-Barré syndrome (GBS), particularly gastroenteritis and respiratory infectious diseases, but epidemiological surveys are rare. This paper details a multicentre matched case-control study carried out within a well-defined Italian population. For each GBS case fulfilling the Asbury and Cornblath criteria, one control was recruited from a neurological (NC) ward and another from a non-neurological (NNC) ward, matched for age, sex, season of disease onset and area of residence. All cases and controls were administered a semistructured questionnaire. The OR was calculated according to the Mantel-Haenszel equation for triplets. Between 1 October 1996 and 30 September 1998, 75 triplets were included in the case-control study. The OR for flu-like syndrome was 7.14 (CI 95%, 3.28-15.52) and for gastroenteritis 3.57 (CI 95%, 1.31-9.72); no other factor reached significance. Our results, based on the clinical and anamnestic features of triplets of patients, support the possible role as risk factors for GBS of infectious diseases, particularly flu-like syndrome and gastroenteritis.