Zika virus can cause paralyzing disorder – study

© Health Canada
The list of serious diseases caused by the Zika virus is growing, as a new study has shown that, apart from causing brain deformations among newborns and grave neurological ailments in adults, it may also be linked to a dangerous paralyzing disorder.

The Zika virus could lead to an inflammation of the spinal cord called acute myelitis, a group of French researchers say in a study published in the Lancet medical journal, based on the case of a 15-year-old girl diagnosed with myelitis in January.

Myelitis affects limb movement, eventually causing paralysis, and can be fatal. In many cases, patients require intensive care and assisted breathing.

In the case described in the study, a teenage girl was admitted to the Pointe-a-Pitre hospital in Guadeloupe, an island in the Caribbean governed by France. The girl was suffering from partial paralysis, limb weakness, and intense pain caused by myelitis.

Nine days after the symptoms began, high levels of Zika virus were found in the girl’s spinal fluid, blood, and urine, while other potential causes of myelitis, including shingles, chicken pox, and herpes virus, were ruled out, AFP reports, citing a statement from France’s Inserm medical research institute.

“The presence of Zika virus in the cerebrospinal fluid of our patient with acute myelitis suggests that this virus might be neurotropic,” meaning it attacks the nervous system, Professor Annie Lannuzel, a medical specialist from the University Hospital Center Pointe-a-Pitre and a co-author of the study, wrote in the article published in the Lancet.

“This is the first published case to offer proof of a link” between myelitis and the Zika virus, Lannunzel told AFP.

However, this is not the first case of Zika being linked to serious disorders. Another French study published on February 29 demonstrated Zika’s potential role in causing a dangerous neurological disease called Guillain-Barré syndrome (GBS), a rare condition in which the body’s immune system attacks the part of the nervous system in control of muscle strength.

A separate US study published on March 4 in the journal Stem Cell provided the first evidence of an existing biological connection between Zika and microcephaly, a severe deformation of the brain and skull among newborns preventing full development of babies’ heads and, in some cases, leading to mental development problems.

A US study conducted by a team from Johns Hopkins’ Institute for Cell Engineering in Baltimore showed that the virus targeted cells involved in unborn children’s brain development, destroying or disabling them.

The team used lab-grown human stem cells to find out which types of cells were infected by Zika. The researchers discovered that the virus mainly targeted human neural progenitor cells, with 90 percent of those infected being killed within three days.

These cells are crucial for the development of the cortex, i.e. outer layer of fetal brain. According to the research team, the study’s findings are consistent with the hypothesis that Zika is responsible for causing microcephaly.

“It is very telling that the cells that form the cortex are potentially susceptible to the virus,” said Guo-li Ming, a professor of neurology at Johns Hopkins’ Institute for Cell Engineering, as quoted by Deutsche Welle.

The outbreak of Zika, which was thought to be a mosquito-borne flavivirus causing symptoms similar to flu, was first reported in Brazil in December of last year. The quick spread of the virus and numerous reports associating it with microcephaly and serious neurological complications soon provoked mounting concern.

The World Health Organization (WHO) has declared the virus a “global public health emergency.” According to WHO estimates, it could affect up to four million people. The majority of the cases have been reported in the countries and territories of Latin America and the Caribbean.

In the meantime, in late February France confirmed its first European case of Zika being transmitted through sexual contact. Two similar cases were confirmed by the US Centers for Disease Control and Prevention (CDC).