Study links Zika virus to paralysing Guillain-Barré syndrome2 min read . Updated: 01 Mar 2016, 08:01 PM IST
According to the study, if 100,000 people are infected with Zika virus, 24 will develop Guillain-Barr syndrome
New Delhi: As researchers race to establish a link between the Zika virus and a spurt in neurological complications, a new study has shown strong evidence linking the virus to an observed rise in cases of Guillain-Barré syndrome (GBS), a neurological disorder which can cause paralysis in adults.
The Zika virus has steadily expanded its reach, since it was first detected in 2015, to 31 countries and territories in the Americas.
The study, published in British medical journal The Lancet, claims to provide the first evidence that Zika virus might cause GBS after an analysis of blood samples from 42 patients diagnosed with the disorder during the Zika virus outbreak in French Polynesia two years ago.
According to the study, if 100,000 people are infected with Zika virus, 24 will develop GBS.
“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," said lead author Arnaud Fontanet from the Paris-based Institut Pasteur in a press release.
From October 2013 to April 2014, French Polynesia experienced a Zika outbreak in which an estimated 32,000 patients consulted doctors about a suspected Zika virus infection. And then 42 patients were diagnosed with GBS between November 2013 and February 2014.
Although Zika virus infection is associated with mild symptoms such as fever, rash, joint and muscle pain and conjunctivitis, the current Zika outbreak in Central and South America was followed by a reported rise in cases of microcephaly (under-developed brains in babies) and GBS.
Between 22 October 2015 and 20 February 2016, a total of 5,640 cases of microcephaly and/or central nervous system malformation have been reported in Brazil, including 120 deaths. During 2015 and 2016, eight countries have reported increased GBS incidence and laboratory confirmation of a Zika virus infection among GBS cases.
While microcephaly refers to a condition where a baby is born with a small head or the head stops growing after birth, GBS is a disorder which affects the immune and nervous systems, and is the leading cause of non-trauma related paralysis. But although evidence is mounting regarding the links of these neurological disorders with the Zika virus, researchers are still not certain as causal links are yet to be established.
A total of 1,708 cases of GBS were reported in Brazil in 2015, which was a 19% increase in cases from the previous year. “There was a surge of GBS in Brazil which was followed 6 months later with a surge in cases of microcephaly. This suggests that Zika virus could be linked with increased incidence of neurological complications, including GBS and microcephaly," said Tarun Dua, World Health Organization (WHO) expert on neurological disorders.
“But can we say that with 100% certainty? Not yet. We need to understand if it could be linked with other infections prevalent in these communities and that is what researchers are focused on," Dua added.
Zika, transmitted by mosquitoes, was declared a public health emergency of international concern by the WHO in early February.