Zika caught 'killing' brain cells

Scientists on Friday said they had found the first evidence of a biological link between the Zika virus sweeping Latin America and microcephaly, a severe deformation of the brain among newborns.

Researchers have shown that Zika virus kills the type of tissue found in the developing brain. Laboratory tests found that the virus targeted key cells involved in brain development and then destroyed or disabled them, they said.

It was able to destroy or disrupt the growth of neural progenitor cells, which build the brain and nervous system, in lab tests.

The findings are the first concrete evidence of a link between the mosquito-borne virus and microcephaly, which until now had been circumstantial, said Guo-li Ming, a professor of neurology at The Johns Hopkins Institute for Cell Engineering, and a co-leader of the research.

There have been more than 4,800 confirmed and suspected cases of babies born with small brains - microcephaly - in Brazil.

It is widely thought that the Zika outbreak is to blame, but this has not been scientifically confirmed.

The team from the Johns Hopkins, Florida State and Emory universities infected a range of tissue samples with Zika virus for two hours and then analysed the samples three days later.

The virus was able to infect up to 90% of neural progenitor cells in a sample leading to nearly a third of cells dying and the growth of the rest being disrupted.

A similar effect in a developing brain could have devastating results.

By itself, Zika is typically no more threatening than a bad cold or a mild case of the flu. Sometimes there are no symptoms at all.