An international team of researchers recently provided evidence linking Zika virus infection to cases of Guillain-Barré syndrome (GBS); In a case-control study, investigators analyzed blood samples from 42 patients diagnosed with GBS during the Zika outbreak that occurred in French Polynesia between October 2013 and April 2014. During that period, an increase in the rare autoimmune condition that attacks the peripheral nervous system was reported, raising the possibility of an association between the Zika virus and GBS.
Because the investigators collected serum samples several weeks after patients were no longer viremic, they had to rely on Zika antibody testing. All patients with GBS had neutralizing antibodies against Zika virus compared with 56% (54/98) in the control group that was asymptomatic for Zika. Anti–Zika virus IgM antibodies were detected in 93% (39/42) of patients with GBS compared with 17% (17/98) in the control group. Of patients with GBS, 88% (37/42) reported symptoms of Zika virus a median of 6 days before the onset of neurological symptoms, suggesting recent past infection.
Recent findings suggest Zika virus (blue) infection can cause Guillain-Barré syndrome. Cynthia Goldsmith/Centers for Disease Control and Prevention
Investigation of dengue serology did not support recent dengue infection in patients with GBS because participants in both the control and GBS groups had immunologic evidence of preexisting dengue infection. Patients with GBS had electrophysiological findings indicative of acute motor axonal neuropathy, a form of GBS that arises and resolves more rapidly than typical GBS.