Zika Virus and Guillain-Barre Syndrome: Is there sufficient evidence for causality
The link between Zika-related weakness and Guillain–Barre syndrome is unproven.
Worldwide concern over Zika virus causing Guillain–Barre syndrome (GBS) soared after recent reports that Zika-related weakness was due to GBS. In April 2016 the World Health Organisation (WHO) reported more than 600 cases of Zika virus related GBS in Latin America and Caribbean countries. Owing to the significant economic impact of a global response plan, and the fact that these cases were identified in countries where gold-standards for confirming acute Zika virus infection and GBS were largely unavailable, it was important to investigate causality between Zika and GBS. This review aimed to investigate the pathogenesis of Zika acute flaccid paralysis and whether there is a link to GBS.
Four case reports (n=5) and one case control study (n=42) were identified. Evidence for a causal relationship between Zika virus infection and GBS is insufficient because clinical, serological, and electrodiagnostic data failed to confirm an acute motor axonal neuropathy variant of GBS and exclude other possible causes of paralysis. Until pathogenesis is established, the authors propose that new cases of Zika-related weakness be termed “Zika virus acute flaccid paralysis,” rather than attributed to variants of GBS, and also call for a moratorium on recommendations for at-risk countries to prepare costly immunotherapies directed at GBS. The authors discuss that insufficient evidence provided by a single case-control study should not have provoked alarm and led to the WHO to create a strategic response plan. This review only searched Pubmed, and did not include data from national and international public health websites (e.g. Centers for Disease Control and Prevention and WHO).