Play Live Radio
Next Up:
0:00 0:00
Available On Air Stations

Zika Virus Makes CDC Consider A Travel Warning For Pregnant Women

The Centers for Disease Control and Prevention is considering a travel warning for countries where Zika virus is circulating. The reason: growing concern among researchers that the virus could be causing babies in Brazil to be born with brain damage.

The Zika virus is named after the Zika forest in Uganda, where it was first identified in the 1940s. For decades it was a rare disease, primarily popping up in Africa and occasionally in Southeast Asia. In 2007, there was a major Zika outbreak in Micronesia. Then in May of 2015 the virus turned up in Brazil.

"And within a year it has spread throughout the continent," says
Nikos Vasilakis, a professor in the department of pathology at the University of Texas Medical Branch in Galveston.

"The Brazilian Ministry of Health estimates that anywhere between a half a million to 1 1/2 million people may be infected," he adds.

Last month, the World Health Organization said Zika had spread to eight other countries in the hemisphere. This month, WHO upped that tally to 14 nations in the Americas.

Usually the virus causes a mild cold. Now it appears that Zika may also be causing a birth defect called microcephaly: babies born with small heads and severe brain damage.

Brazil has seen cases of microcephaly skyrocket from about 200 a year to more than 3,000 in 2015.

Vasilakis has been working in northeastern Brazil to set up monitoring systems for Zika. He believes these 3,000 cases are just the tip of the iceberg.

The babies being born now, he says, reflect damage that could have "occurred about six or seven months ago during the first trimester of pregnancy."

That means there could be more babies on the way with this severe form of brain damage.

The situation is so dire that some health officials in Brazil have suggested that women in places with high rates of Zika transmission should avoid getting pregnant.

Dr. Lyle Petersen, who's leading the CDC response to the Zika outbreak, says this virus poses a serious threat to travelers to countries where the virus is spreading, including much of Latin America and the Caribbean.

"Given the potential and increasingly strong association with these birth defects, this is a matter of some considerable concern," says Petersen, who is the director of the Division of Vector-Borne Diseases.

Petersen says travelers can protect themselves by taking steps to avoid mosquito bites. That's always been an important strategy in the tropics, he says, even before Zika showed up.

Any new travel warning could be devastating to local tourism industries.
However, Vasilakis, at the University of Texas, says that given the damage this virus may cause to fetuses, a warning to pregnant women is prudent.

"If my wife was pregnant or planning to be pregnant I would not feel comfortable with her traveling to those areas," he says.

The CDC is expected to come out with new guidance for pregnant women about traveling to Zika-affected countries soon.

Copyright 2023 NPR. To see more, visit

Jason Beaubien is NPR's Global Health and Development Correspondent on the Science Desk.