Zika is bad - Experts

Researchers said aside that Zika virus caused microcephaly and brain abnormalities in foetuses, new study had revealed that adult brain cells critical to learning and memory may also be infected.

The research published in Cell Stem Cell journal in Washington, U.S. on Friday, reveals that more studies are needed to determine if the damage has long-term biological implications or the potential to affect behaviour.

It said that for now, the findings suggested the possibility that the Zika virus may be more harmful than previously believed.

News Agency of Nigeria (NAN) reports that Joseph Gleeson, a professor at the Rockefeller University and one of the co-authors of the study, said that the research was the first study looking at the effect of Zika infection on the adult brain.

“Based on our findings, getting infected with Zika as an adult may not be as innocuous as people think.

 “In developing foetuses, the brains are comprised entirely of neural progenitor cells, the kind of stem cells that in healthy individuals grow and divide rapidly to become fully formed neurons,’’ he said.

Gleeson said that current evidence suggested that Zika could target neural progenitor cells in developing foetuses, leading to microcephaly and a wide variety of developmental disabilities.

He said that the research revealed that the mature brain retained some niches of the neural progenitor cells, which the researchers suspected were also vulnerable to Zika infection.

“These niches exist primarily in the sub-ventricular zone of the anterior forebrain and the sub-granular zone of the hippocampus, two regions vital for learning and memory in mice.’’

Gleeson said he and his colleagues created a mouse model and then injected a modern Zika strain into the mice’s bloodstream to mimic Zika infection in humans.

According to him, the results showed adult neural progenitor cells can indeed be hijacked by the virus.

“It was very clear that the virus wasn’t affecting the whole brain evenly, like people are seeing in the foetus.

“In the adult, it’s only these two populations that are very specific to the stem cells that are affected by virus.

 These cells are special, and somehow very susceptible to the infection,’’ he said.

The researchers recognised that healthy humans may be able to mount an effective immune response and prevent the virus from attacking.

However, they suggested that some people, such as those weakened immune systems, may be vulnerable to the virus in a way that had not been recognized.

They said that although there were still many unanswered questions, as the findings raised the possibility that Zika was not simply a transient infection in adult humans, and that exposure in the adult brain could have long-term effects.

“The virus seems to be travelling quite a bit as people move around the world.’’

They advised that as a result of the study, the public health enterprise should consider monitoring for Zika infections in all groups, not just pregnant women.