A new study on 42 patients who suffered paralysis in French Polynesia is confirming what doctors in South America are rapidly finding out - that the Zika virus seems to be able to trigger Guillain-Barre syndrome. 

Guillain-Barre causes temporary paralysis, and most patients eventually recover and regain full movement, which can take months.  And in its most extreme cases, patients are left dependent on life support and in rare cases it could be fatal.  Doctors in Colombia and Venezuela are reporting several such cases in their respective Zika outbreaks.

The study appearing in the British medical journal The Lancet examined blood samples from 42 patients who developed the neurological problems of Guillain-Barre during the Zika outbreak in French Polynesia in 2013-2014.  Finding the link wasn't easy, because the Zika virus generally disappears from the body a week after infection.  The researchers had to identify antibodies that kill Zika in the blood samples. 

Authors caution that more study is necessary, but leading scientists are encouraged:  "This is a compelling paper that provides a good deal of objective data to suggest an epidemiological link between recent Zika infection and increased risk of Guillain-Barre syndrome," said Tufts University professor of Neurology Dr. Kenneth C. Gorson.

The researchers were also able to extrapolate that one in 4,000 Zika infections could lead to Guillain-Barre.  And that means hundreds or thousands of Guillain-Barre cases in a Zika outbreak that hits millions of people.

"The scale of the crisis unfolding in Latin America has taken us all by surprise, and we should be prepared for further unforeseen complications of Zika virus infection to emerge in the coming weeks and months," said Dr. Jeremy Farrar, director of the UK biomedical research charity The Wellcome Trust.