A comparison of rates of Guillain-Barre syndrome before and after Zika arrived in seven countries has found a strong association between the virus and the illness, researchers from the Pan American Health Organization said on Wednesday.
The current Zika outbreak was first detected in Brazil last year and has since spread across the Americas and the Caribbean.
Pregnant women are considered to be at greatest risk because the virus can cause severe birth defects, including microcephaly, which is marked by small head size and underdeveloped brains. In Brazil, Zika has been linked to more than 1,800 cases of microcephaly.