Researchers have discovered that Zika virus can secretly occupy a space in a vaginal tract or in the bloodstream of infants for days without any indication.

According to the study, the virus can remain hidden in the body for several days and can have dangerous consequences in the future. The infection is believed to replicate in the vagina, researchers said. The conclusion was drawn following their lab test on mice where they observed sexual transmission of the virus, which is normally believed to be the reason for birth defects in newborns.

On Wednesday, a letter was published in the New England Journal of Medicine. The story revolved around a Brazilian boy who was tested positive for the infection not before days after his birth. Until he turned six-month-old, he started suffering from severe muscle contraction along with other neurological breakdowns.

The boy, however, did not show any symptoms for microcephaly and was diagnosed healthy when he was born. He went for regular checkups for two months but there were no reports of developmental issues then. He was considered prone to the virus attack as his mother already had Zika virus symptoms during the third trimester of pregnancy.

In most of the cases, according to CNN, the virus remains in the blood for almost a week and then it resolves. The infection even it persists in urine or saliva, it stays there for some weeks and then it disappears. In such instances, only antibody testing of the blood can help diagnose that there was the virus present sometime in the past.

The Yale University team’s study published in the journal Cell stated that the vaginal tract’s role in transmitting the infection can be robust source imposing “dire consequences.”

While the pregnant mice were being studied, they were infected vaginally with Zika virus, which spread the infection to the fetal brain.”We saw significant virus replication in the genital tissue, up to four to five days,” Howard Hughes Medical Institute’s immunobiology professor and investigator Akiko Iwasaki said as quoted by The Daily Mail.