French researchers suspect that Zika Virus is responsible for the cause of Guillain-Barré Syndrome (GBS), a severe form of limb paralysis that is often accompanied by respiratory impairment requiring intensive care.
The multidisciplinary study was conducted by researchers from the Institut Pasteur, the Conservatoire national des arts et métiers (CNAM), the Institut Louis Malardé, the French Polynesia Hospital Centre, and the Public Hospitals of Paris (AP-HP).
This was initiated after the largest Zika virus outbreak ever described in French Polynesia between October 2013 and April 2014.
As part of the study, researchers analysed blood samples from 42 patients who developed a Guillain-Barré syndrome during the Zika virus outbreak in French Polynesia.
The researchers then tested the Guillain-Barré syndrome patients against two control groups.
The first group of people were of the same age and from the same island being treated for non-febrile illness, while the other group included people of same age with acute Zika virus disease and no neurological symptoms.
Blood samples from two comparison groups were then tested to look for links between Zika virus, Guillain-Barré syndrome and dengue virus.
Of the 42 patients diagnosed, 41 had antibodies to Zika virus in their blood, showing they had recently been infected with Zika. Of the 98 people in the first comparison group, only 35 (36%) had Zika antibodies.
While all the patients being treated for Zika had signs of Zika viral infection in their blood, none of the Guillain-Barré patients did, suggesting the syndrome happens once the body has fought off the virus.
Although most people with Guillain-Barré syndrome also had signs of previous infection with dengue virus (95%), so did most of the people in the comparison groups (89% and 83%).
Institut Pasteur emerging diseases epidemiology unit head Arnaud Fontanet said: "This work is significant because it allows for the confirmation of the role of Zika virus infection in the occurrences of the severe neurological complications that constitute Guillain-Barré Syndrome.
"This indicates that the regions affected by the Zika virus epidemic are likely to see a significant increase in the number of patients with serious neurological complications, and when possible, should increase the capacity of healthcare facilities to receive patients needing intensive care."
The study was funded by Labex Integrative Biology of Emerging Infectious Diseases, EU 7th framework programme PREDEMICS and the Wellcome Trust.
Image: Infected cells by the Zika virus in transmission electron microscopy. Photo: © Institut Pasteur.