Researchers say evidence links Zika virus to spike in cases of severe neurological disorder characterised by paralysis.

A new study has provided the first evidence that the Zika virus may be the cause for a spike in cases of a severe neurological disorder called the Guillain-Barré syndrome (GBS).

The study, published in the medical journal Lancet, showed 42 patients developed symptoms of GBS, which causes the immune system to attack parts of the nervous system.

The neurological symptoms include acute motor axonal neuropathy, which is characterised by severe paralysis. It also caused respiratory problems in about a third of the patients who needed medical assistance to breathe properly, the report said.

However, none of the patient-subjects died.

"This is the first study providing evidence for Zika virus infection causing Guillain-Barré syndrome. Because Zika virus is spreading rapidly across the Americas, at risk countries need to prepare for adequate intensive care beds capacity to manage patients with Guillain-Barré syndrome,” the study said.

The World Health Organization described Zika, which is spread by mosquitoes, as apublic health emergency of global concern in February.

There are also suspicions that the virus could be linked to Brazil’s rise in cases of microcephaly - a condition of underdeveloped brains in newborns.

However, the Colombian government has questioned the link, saying it has not seen any evidence for it after more than 3,000 pregnant women in the country contracted Zika.

But Colombia’s health officials have said that at least three people who died from Zika had symptoms of GBS.

GBS is lethal in about five percent of cases, and another five percent suffer lasting disabilities. More than a quarter of patients require intensive care.

With 1.5 million cases of Zika infection already recorded in Brazil, and tens of thousands in neighbouring countries, researchers warn that an outbreak of Guillain-Barré could strain healthcare facilities, especially outside of big cities.

"In areas that will be hit by the Zika epidemic, we need to think about reinforcing intensive care capacity,” said Arnaud Fontanet, a co-author of the study and a professor at the Emerging Diseases Epidemiology Unit of the Institut Pasteur in Paris.