乌鸦传媒

VANCOUVER -- A Guillain-Barre Syndrome outbreak that occurred at four times the normal background levels appeared to track with the outbreak of Zika virus, CDC researchers reported here.

In Brazil where there is an ongoing Zika virus outbreak, the incidence of Guillain-Barre Syndrome was 7.5 cases per 100,000 cases per year while the background cases of Guillain-Barre Syndrome is about one to two cases per 100,000 cases per year, said, of the CDC's Division of High-Consequence Pathogens and Pathology, National Center for Emerging and Zoonotic Infectious Diseases, in Atlanta.

"These cases are four-fold higher than you would typically expect," Sejvar told 乌鸦传媒 at a press conference at American Academy of Neurology (AAN) annual meeting.

The CDC linked Zika virus to neurological birth defects in children whose mothers carry the virus.

According to the National Institute of Neurological Disorders and Stroke (NINDS), "Guillain-Barré syndrome is a disorder in which the body's immune system attacks part of the peripheral nervous system. The first symptoms of this disorder include varying degrees of weakness or tingling sensations in the legs. In many instances the symmetrical weakness and abnormal sensations spread to the arms and upper body. These symptoms can increase in intensity until certain muscles cannot be used at all and, when severe, the person is almost totally paralyzed."

Guillain-Barre can strike at any age and impacts both sexes. It usually occurs a few days or weeks after the patient has had symptoms of a respiratory or gastrointestinal viral infection, according to the NINDS.

Sejvar said that the outbreak of Guillain-Barre Syndrome in Brazil followed an earlier outbreak in French Polynesia, in the South Pacific.

The virus is transmitted by the ubiquitous Aedes aegypti mosquito, prevalent in French Polynesia and Brazil.

One theory as to disease dissemination is that individuals carrying the Zika virus from the Tahiti-area traveled to Brazil for the 2014 FIFA World Cup soccer championships, Sejvar explained, but he cautioned that Sejvar the connection between French Polynesia and the is speculative.

The Zika virus continues its spread across South and Central American, and the Caribbean. All U.S. cases are related to people returning to or visiting the U.S. from infected regions. Sejvar said that currently there are no cases in which the virus has been transmitted by mosquitoes in the U.S.

However, Sejvar said at the AAN press conference that the CDC is setting up a monitoring program in Puerto Rico where there is an abundance of A. aegypti mosquitoes.

"What we know is that Zika is spread by A. aegypti, and the mosquitoes carry a very similar virus called dengue; we know that dengue continues to be a significant problem in Puerto Rico," he explained.

"So we are anticipating that because of the spread of this mosquito that Zika could eventually be a potential problem in Puerto Rico. In advance of potential introduction of Zika into the population of Puerto Rico, we are trying to be proactive and establish prospective surveillance for Guillain-Barre Syndrome, and other complications of Zika, and try to better define the association between Zika and Guillain-Barre and other complications," Sejvar said.