Zika virus causes Guillain-Barre syndrome: study

A recent study says that an analysis of blood samples from 42 patients diagnosed with Guillain-Barre Syndrome (GBS) during the Zika virus outbreak in French Polynesia provides the first evidence that Zika virus might cause GBS, a severe neurological disorder.

Based on the analysis of data from French Polynesia, if 100000 people were infected with Zika virus, 24 would develop GBS.

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-Barre syndrome (GBS) is a disorder which affects the immune and nervous systems, and is the leading cause of non-trauma related paralysis.

Symptoms develop rapidly and include weakness in the legs and arms, muscle weakness and pain. In about 20-30% of cases, severe GBS can lead to respiratory failure, and about 5% of patients die.

GBS is usually triggered by an infection and can sometimes develop following infections of herpes, influenza or dengue virus. Across Europe and North America, GBS affects approximately 1-2 people out of 100000 per year.

The aim of the study was to determine the link between Zika virus infection and GBS. Since French Polynesia is also prone to outbreaks of dengue virus, the researchers also wanted to see whether dengue virus was an additional risk factor for GBS.

The study has been published in Lancet.