Zika linked to a spectrum of neuroinflammatory diseases

The 2015 Zika outbreaks in the Americas were notable for the recognition that Zika virus could be associated with neurological conditions. It was found that the overall risk of congenital neurologic abnormalities in fetuses and liveborn children of mothers enrolled in the Centers for Disease Control and Prevention’s Zika Pregnancy Registry with definite laboratory evidence of Zika virus infection during pregnancy was approximately 17 times higher than the expected baseline rate in uninfected mothers. It wasn’t until later, however, that GBS became the first non–pregnancy-related neurological syndrome to be associate with Zika in adults.

It is critically important to understand both the spectrum and frequency of Zika virus–induced neurologic diseases. The article by Dr. da Silva and colleagues in this issue of JAMA Neurology represents an initial approach to this problem. During the reporting period, they found that 93% of the patients with GBS (27 of 29), 71% of the patients with encephalitis (5 of 7), 67% of the patients with transverse myelitis (2 of 3), and the single patient with chronic inflammatory demyelinating polyneuropathy showed evidence of recent Zika virus infection, indicating a link between neurological syndromes and Zika.

However, it should be noted that, because of factors including referral bias, a study such as this cannot determine exact frequencies of Zika virus infection among patients with the syndromes examined, but it may serve to help confirm that Zika can be associated with such syndromes.

Kenneth L. Tyler, MD, is the Louise Baum Endowed Professor and Chair of the department of neurology at the University of Colorado at Denver, Aurora. Karen L. Roos, MD, is the John and Nancy Professor of Neurology at the University of Indiana, Indianapolis. They published these comments in an editorial accompanying the da Silva et al. article in JAMA Neurology (2017 Aug 14. doi: 10.1001/jamaneurol.2017.1471). Neither author reported any financial disclosures.