A new report on Zika leads to more questions on how long after birth babies may show symptoms.
"It certainly reveals something that is very concerning, something we have been suspicious of, and unfortunately, now this one case is contributing to our fear," said Dr. David Soria at Wellington Regional Medical Center.
The report, published in the New England Journal of Medicine, looked at one case, where the baby's mother contracted the Zika virus late in pregnancy. In this case, researchers say just two months after birth, there were no developmental issues, but Zika was present in some bodily fluids. At six months, the baby had signs of brain impairment.
Researchers believe this report points to the importance of following up long after birth, when it comes to infants who may have been exposed to the Zika virus in utero.
"Now the concern is are you out of the woods?" said Dr. Soria, "You may not have those obvious birth defects, but there still may be the possibility of delayed brain defects or developmental down the road as the child develops."
Dr. Soria says this suspicion has been there amongst medical professionals, but more work needs to be done.
"It's just one case, so there's a lot more studies or observations required before we can really prove causality," he said.
Researchers say now there is the need is there for better tracking of babies development, if they were exposed in the womb.
"The brain is obviously not done developing once the baby is born," he said. "And does the Zika that remains in the fetuses and newborn infants' blood continue to cause growth and developmental problems as the child grows? In this one case, it certainly looks like it may be a yes."