Abstract
BACKGROUND: Haemophilus influenzae is considered a causative agent of Guillain-Barré syndrome (GBS) and Fisher syndrome, but the frequency of this infection in GBS is controversial. OBJECTIVE: To determine whether isolation of H influenzae indicates it is a causative agent in GBS and Fisher syndrome. RESULTS: Four (15%) of 27 patients with GBS and Fisher syndrome in whom H influenzae was isolated were also seropositive for Campylobacter jejuni. Antiganglioside IgG antibodies in these four patients did not cross react with their H influenzae lipo-oligosaccharides, whereas antiganglioside antibodies in the four patients with positive serology for H influenzae did. CONCLUSIONS: The findings suggest that H influenzae isolation is not always indicative of the causative agent in these syndromes and that tests for other infections should be made, even in cases of positive culture.