The latest finding strengthens a suspected link between infection with the mosquito-borne virus and the syndrome, which causes temporary paralysis in its victims.
While the Zika virus doesn't pose a significant health threat to most people, it can cause a devastating birth defect called microcephaly, which leads to babies born with abnormally small heads and brains.
The vast majority of Zika infections have been in Latin America and the Caribbean, with Brazil the epicenter.
In areas where Zika outbreaks were reported, the researchers behind the new study documented a significant increase in Guillain-Barre cases. Guillain-Barre is known to be caused by infection with other viruses, the scientists noted in their report.
More than 164,000 confirmed and suspected cases of Zika and almost 1,500 cases of the Guillain-Barre syndrome were reported from April 2015 to March 2016 in Brazil, Colombia, the Dominican Republic, El Salvador, Honduras, Suriname and Venezuela. The jump in Guillain-Barre cases followed peaks in Zika infection, the analysis found.
The researchers, from the Pan American Health Organization in Washington, D.C., and the health ministries of the affected countries, concluded "that [Zika] infection and the Guillain-Barre syndrome are strongly associated. Additional studies are needed to show that [Zika] infection is a cause of the Guillain-Barre syndrome."
The report was published Wednesday in the New England Journal of Medicine.
Meanwhile, on Tuesday the head of the U.S. Centers for Disease Control and Prevention said that federal funds to combat the Zika virus are nearly exhausted and there will be no money to fight a new outbreak unless Congress approves more funding.
As of Friday, the CDC had spent $194 million of the $222 million it was given to fight the virus, said agency director Dr. Thomas Frieden, The New York Times reported.
Congress broke for its summer recess without approving additional funding. With Zika circulating in Florida, Frieden said the need for new funding was urgent.
The CDC has sent about $35 million to Florida -- which has several dozen cases of locally transmitted Zika infections -- and much of that has been spent, Frieden said. But, he added, if another cluster of Zika cases occurs in Florida, or if there is an outbreak in a second state, the agency would not be able to send emergency funds, according to The Times.
"The cupboard is bare, there's no way to provide that," he said at a briefing with reporters in Washington, D.C.
Senate Republicans have scheduled a vote on $1.1 billion in Zika funding for next Tuesday, when Congress comes back into session, according to a spokesman for Senate majority leader Mitch McConnell, Republican of Kentucky.
But Democrats oppose that package because it would exclude Planned Parenthood from the list of providers that would get new funding for contraception to combat the spread of Zika, which also can be transmitted sexually.
Public health experts say the funding issue is critical because the Gulf Coast, where the Aedes mosquito that transmits Zika mostly lives, is only halfway through peak mosquito season. There's a high risk that Zika could start circulating in New Orleans or Houston, the newspaper reported.
The danger of mosquito-borne Zika infection for pregnant American women became more imminent this month, with two neighborhoods in the Miami area reporting cases of locally acquired infection. The CDC is now advising that pregnant women avoid traveling to these areas of Miami to reduce their risk of contracting Zika.
The CDC also is advising pregnant women not to travel to an area where active Zika transmission is ongoing, and to use insect repellent and wear long pants and long-sleeved shirts if they are in those areas. Partners of pregnant women are advised to use a condom to guard against sexual transmission during pregnancy.
The U.S. Centers for Disease Control and Prevention provides more information on mosquito-borne diseases.
This Q & A will tell you what you need to know about Zika.
To see the CDC list of sites where Zika virus is active and may pose a threat to pregnant women, click here.
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