Brain Defects Related To Zika Virus Found In Babies Without Microcephaly

One of the common indicators of Zika virus in infants is microcephaly, a congenital condition where babies have abnormally small heads. However, a new report found that newborns can also exhibit Zika-related brain defects even though they have normal-sized heads.

Zika Congenital Infection Shouldn't Equate With Microcephaly

The research, which was published in the journal The Lancet, found 100 cases of Zika infection in Brazilian babies who have normal head circumferences, according to the U.S. News & World Report (via HealthDay).

Cesar Victora, the study's lead author and a professor of epidemiology at the Federal University of Pelotas in Brazil, said 30 percent of the cases didn't show another sign of Zika infection in pregnant mothers -- a rash in late pregnancy. In some of the cases, mothers affected with Zika have babies with brain damage and developmental delays even though they don't have microcephaly.

Accurate Prenatal Test For Zika

Victora's research team said a baby's skull completes its development stage by week 30 of gestation. Brazilian experts Dr. Jorg Heukelbach of the University of Ceara, and Dr. Guilherme Loureiro Werneck of the University of Rio de Janeiro said the development of a definitive test for Zika virus is highly important.

According to the two experts, an accurate blood test should be available for pregnant women alongside regular prenatal care. Dr. William Schaffner, an infectious disease expert at Vanderbilt University Medical Center, said in an interview with ABC News that Zika gets "nastier" the more they know about the virus.

Some of the babies affected with Zika display blindness and hearing defects after birth. Others, however, appear normal when they were born but display issues with their brain, hearing and vision later on.

Dr. Julie VanSchalkwyk, head of obstetrics and gynecology at B.C. Women's Hospital in Vancouver, Canada, said ultrasound findings alone isn't enough to rule in or rule out Zika virus infection, CBC News reported. People affected with Zika usually don't display symptoms.

The virus is transmitted by Aedes aegypti and Aedes albopictus mosquitoes. It can be transferred by males via unprotected sex as well.

Experts are onto an effective vaccine against Zika. Two separate research teams are developing vaccines, and both are capable of protecting mice against the virus with just a single shot.

However, these vaccine candidates need to work on larger animals before can finally be administered on human, CNBC noted. Experts from the National Institutes of Health in the United States said larger trials for a Zika vaccine could begin in late 2017, with a vaccine likely to be available to the public in early 2018, BBC reported.