A latest new study suggests that Zika could be proved much more danger for unborn babies than previously thought.
Moreover the virus may also cause ever lasting eye diseases to people of all ages.
According to the invention of the scientists from University of Wisconsin Madison in the US Zika virus infection passes efficiently from a pregnant monkey to its foetus, spreading in flammatory damage throughout the tissues that support the foetus and its developing nervous system.
Moreover, the virus is seeming like a wider threat in human pregnancies than generally appreciated, researchers stated.
Researchers followed the pregnancies from infection in the first or third trimester, regularly assessing maternal infection and foetal development and examining the extent of infection in the foetus when the pregnancies reached term.
They infected four pregnant rhesus macaque monkeys with a Zika virus dose similar to what would be transferred by a mosquito bite, and found evidence that the virus was present in each monkey's foetus.
"That is a very high level - 100 per cent exposure - ofthe virus to the foetus along with inflammation and tissueinjury in an animal model that mirrors the infection in humanpregnancies quite closely," said Ted Golos, professor at UW-Madison.
"It is sobering. If microcephaly is the tip of the iceberg for babies infected in pregnancy, the rest of the iceberg may be bigger than we have imagined," said Golos.
Three of the foetuses involved had small heads, but not quite so small relative to normal that they would meet the human standard for diagnosing microcephaly.
Microcephaly is the most striking and widely discussed result of Zika infection since Brazilian doctors raised alarm in 2014 of many babies with arrested brain development.
The new study did not find abnormal brain development, but the researchers did discover unusual inflammation in the foetal eyes, in the retinas and optic nerves, in pregnancies infected during the first trimester.
"Our eyes are basically part of our central nervous system. The optic nerve grows right out from the foetal brain during pregnancy," said Kathleen Antony, professor at UW-Madison.
"So it makes some sense to see this damage in the monkey sand in human pregnancy - problems such as chorioretinalatrophy or microphthalmia in which the whole eye or parts ofthe eye just don't grow to the expected size," said Antony, author of the study published in the journal PLOS Pathogens.
The similarities between the monkey pregnancies and reported complications in Zika-affected human pregnancies further establish Zika infection in monkeys as a way to study the progression of the infection and associated health problems in people, researchers said.
(With PTI inputs)