Analysis of blood samples from 42 patients diagnosed with Guillain-Barré syndrome (GBS) during the Zika virus outbreak in French Polynesia provides the first evidence that Zika virus might cause GBS, a severe neurological disorder, according to new research in The Lancet.
Based on the analysis of data from French Polynesia, if 100,000 people were infected with Zika virus, 24 would develop GBS.
“This is the first study to look at a large number of patients who developed Guillain-Barré syndrome following Zika virus infection and provide evidence that Zika virus can cause GBS,” says lead author Professor Arnaud Fontanet from the Institut Pasteur, Paris, France.
“Most of the patients with GBS reported they had experienced symptoms of Zika virus infection on average 6 days before any neurological symptoms, and all carried Zika virus antibodies.”
In between October 2013 to April 2014, French Polynesia experienced the largest Zika outbreak to be reported at the time.
An estimated 32000 patients consulted a doctor about a suspected Zika virus infection, and 42 patients were diagnosed with GBS between November 2013 and February 2014.
Zika virus infection is associated with symptoms such as fever, rash, joint and muscle pain and conjunctivitis. The current Zika outbreak in Central and South America was followed by increased reports of cases of microcephaly and GBS, leading the World Health Organisation to declare it a global emergency.
Guillain-Barré syndrome (GBS) is a disorder which affects the immune and nervous systems, and is the leading cause of non-trauma related paralysis.
GBS is usually triggered by an infection and can sometimes develop following infections of herpes, influenza or dengue virus.
Professor Fontanet adds: “Although it is unknown whether attack rates of Zika virus epidemics will be as high in affected regions in Latin America than in the Pacific Islands, high numbers of cases of Guillain-Barré syndrome might be expected in the coming months as the result of this association. The results of our study support that Zika virus should be added to the list of infectious pathogens susceptible to cause Guillain-Barré syndrome.”