The Zika virus would be responsible for the increase in cases of Guillain-Barré syndrome. But researchers do not know how it causes these neurological disorders.
Zika virus is responsible for the rise in cases of Guillain-Barré syndrome, a post-infectious neurological disorder, Colombian doctors say in the New England Journal of Medicine.
The link between this complication causing progressive paralysis and this virus transmitted by the mosquito Aedes has been suspected since the 2013 epidemic in French Polynesia. This first large-scale epidemic affects half of the population, and 42 cases of Guillain-Barré syndrome have been identified. But at the same time, dengue is rampant. Difficult then to confirm that Zika is responsible.
Three years later, the dangerousness of this virus resurfaces. Out of around sixty countries affected by the Zika epidemic since 2015, eleven (1) report an abnormal proportion of people suffering from this syndrome. Brazil, the epicenter of the epidemic outbreak, has been hit hard. Very quickly, Colombia was also affected. The French departments of America are not spared either. But again, you have to prove the guilt of the virus.
More than 600 neurological complications
In Colombia, between November 2015 and March 2016, nearly 60,000 people were reportedly infected with Zika. To this proportion is added 400 patients suffering from neurological complications, including 270 cases of Guillain-Barré. Usually, the country registers 250 cases in a year.
To carry out their work, the Colombian team of doctors studied the medical records and blood and urine samples of 68 people with this syndrome. Among them, 66 presented symptoms characteristic of the infection (skin rash with or without fever, joint pain, conjunctivitis). Blood and cerebrospinal fluid tests in 42 patients revealed the presence of the virus in 17 of them.
In addition, the researchers’ observations show that the syndrome can start 4 days after the onset of symptoms (median period) and up to 48 days after. Along with weak limbs and tingling, paralysis of half of the face is one of the most common signs. In addition, electromyographies (examination of the muscles and nerves) carried out in 46 patients show the nerve damage: the myelin sheaths around the neurons are destroyed. Result: the transmission of the nerve signal is slowed down, which causes muscle weakness and paralysis.
Many cases still awaited
For Colombian researchers, all these elements combine to prove the responsibility of the Zika virus. They point out, however, that it is still unclear how it causes this neurological complication.
In a remark accompanying the study, two specialists recalled that the epidemic is not over and that many cases of Guillain-Barré could be identified on the American continent in the coming months.
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