Zika
A new study published in a medical journal, Lancet suggested Zika virus's link to paralysis. In Pictures: Brazilian Army soldiers distribute pamphlets with information to combat the Aedes aegypti mosquito during the National Day of Mobilization Zika Zero at Central train station in Rio de Janeiro, BraziReuters

The Zika virus scare is refusing to die down with a new study suggesting a strong link between Zika virus and Guillain-Barré syndrome(GBS) – a health condition in which the patient's immune system attacks itself, resulting in muscle weakness or paralysis.

The study -- published in medical journal Lancet -- involved 42 cases of GBS in French Polynesia. It reported a significant increase in paralysis cases between October 2013 and April 2014, when the region experienced the largest Zika virus outbreak.

The study said 93 percent of patients with GBS had Zika virus and 88 percent had experienced a transient illness six days before the onset of the neurological symptoms, hinting at the recent Zika virus infection.

The World Health Organization (WHO) said Friday that eight countries and regions – Brazil, French Polynesia, Martinique, El Salvador, Suriname, Puerto Rico, Colombia and Venezuela – have reported that GBS cases may potentially be linked to Zika virus.

"This is a compelling paper that provides a good deal of objective data to suggest link between recent Zika infection and increased risk of GBS," said Kenneth C Gorson, professor of Neurology at Tufts School of Medicine, The New York Times reports. Gorson was not affiliated with the paper.

He said this is the first case-control study to establish a potential relationship between Zika virus infection and GBS.

WHO said though Zika virus is not proven to be a cause of increased GBS incidence, a causal role for Zika virus is a strong possibility."Further investigations are needed to identify the potential role of other factors (including infections) associated with GBS," the organisation said.

As per WHO estimates, the annual incidence of GBS is may be between 0.4 and 4 cases per 100,000 inhabitants per year. In North America and Europe, GBS is more common in adults and increases steadily with age. Studies have shown that GBS affects men more than women.

WHO said 52 countries and territories reported local transmission of Zika virus between Jan 2007 and Feb 2016. The Zika virus infection has spread across many regions since the detection of its first case in the US in 2015. Apart from GBS , Zika is suspected to be causing microcephaly – a neurological disorder in which babies are born with abnormally small heads.