Alert! Zika virus may also infect placenta, say researchers

Zika Virus- a name that had almost gone into oblivion is back in the news and for another shocking reason!

Two Indian-origin scientists have made some frightful observations about how the deadly virus can affect a woman's placenta:

• Zika virus can infect and replicate the immune cells from the placenta, without actually killing them
• The infected cells can easily pass on from the infected placenta into the developing brain cells of the foetus
• Virus could infect another type of placental cell, called cytotrophoblasts (external lining in a developing embryo), but only after a couple of days delay
• Viral replication differs from one woman to the other and therefore, some women’s placentae may be more susceptible to viral infection than others

What the researchers say...

“Our results substantiate the limited evidence from pathology case reports,” said Mehul Suthar from Emory University in the US, while speaking to a leading daily. The findings that were published in the journal Cell Host & Microbe, are a work of Indian-origin Mehul Suthar and Rana Chakraborty from Emory University.

They came up with the observations after the found that Zika virus was capable of infecting placental macrophages, called Hofbauer cells, in cell culture.

“It was known that the virus was getting into the placenta. But little was known about where the virus was replicating and in what cell type,” Suthar was quoted as saying.

A woman's placenta is supposed to nourish and help the developing foetus grow and protect the embryo from any infection. But this new revelation has proved that with Zika virus even that is not possible.

Although only a handful of viruses can make their way past the placental wall and infect a growing foetus. This includes Rubella, HIV, Herpes as well as Hepatitis B and C. And, now with this news, Zika virus has joined that list.

Continue reading to know another important revelation they made about the placenta and Zika virus.

What they also found...

“Not every pregnant woman who is infected by Zika transmits the virus to her foetus. Host genetics and non-viral factors, including nutrition and microbiota, as well as timing may be influencing infectivity,” Suthar was quoted as saying.

“A better understanding of these factors could allow the design of preventive measures, and eventually antiviral therapies,” he added.

 For the purpose of this study, the researchers derived cells from full-term placentae, obtained from healthy volunteers who delivered by cesarean section.

Why this study is important?

The researchers observed that for viruses that are related to Zika (flaviviruses) such as dengue virus, yellow fever virus and even West Nile virus, it is rare for the infection to be transmitted from mother to foetus.

This is primarily because of the protective role of the placenta. It is known to separate the circulatory systems of the mother and foetus, they said.

“Zika may be unique in its ability to infect placental cells and cross the placental barrier, in comparison with other flaviviruses,” Suthar was quoted.

“It is still possible that disruption of the placental barrier - as seen in a recent case report - or antibody-mediated mechanisms are contributing to placental infection by Zika virus,” he said.

Read: What every pregnant woman must know about the ‘Zika virus’

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(With Inputs from IANS)