1 in 7 Zika babies born with defects in US territories (Update)

August 7, 2018 by Kerry Sheridan
Brenda Pereira (23) holds her four-month-old baby Maria Fernanda as they wait for medical exams at the State Brain Institute (IEC) in Rio de Janeiro, Brazil in early 2017

About one in seven babies who were exposed to the Zika virus in the womb have at least one developmental defect a year later, said a US study Tuesday.

The rate of abnormalities—about 14 percent—represents more than 30 times the level expected in infants that were not exposed to the mosquito-borne virus, officials with the US Centers for Disease Control and Prevention said.

Health problems included small head size—known as microcephaly—brain or eye damage, seizures, and developmental delays, said the CDC Vital Signs report, the largest study to date on outcomes of babies born to mothers who were infected with Zika during pregnancy.

"Some of these problems were not apparent at birth and were identified as the babies grew older," said the report, which included more than 4,800 pregnancies that had positive lab tests for Zika in the US territories of American Samoa, Micronesia, Puerto Rico, Marshall Islands, and US Virgin Islands from 2016-2018.

The report focused on the US territories, which were hardest hit by the outbreak, and did not include US mainland cases.

"From these pregnancies, 1,450 babies were at least one year old and had some follow-up care reported for this analysis," it said.

A total of 203 "had a Zika-associated birth defect, neurodevelopmental abnormality possibly associated with congenital Zika virus infection identified, or both."

The rate of Zika-related birth defects is on par with prior studies in Brazil and other areas that were hard hit by Zika, said Peggy Honein, director of CDC's Division of Congenital and Developmental Disorders.

"We have pretty consistently seen five to 10 percent of the babies from pregnancies with Zika having one of these brain or eye defects, or microcephaly," she told reporters on a conference call.

"There have been some reports that have used different criteria and have included a broader range of outcomes, including some findings on MRI imaging of unknown clinical significance and if you use broader criteria you will see more babies affected," she added.

"We think there isn't a geographic difference but more of a case-criteria difference."

Transmission ongoing

There have been 74 cases of Zika so far this year in the US territories, almost all in Puerto Rico, said Lyle Pedersen, director of CDC's Division of Vector Borne Infectious Diseases.

"There is ongoing transmission in Puerto Rico, but it is at a much lower level than obviously we have seen in previous years," he said.

A massive outbreak of Zika swept Latin America and the Caribbean beginning in 2015, eventually reaching 86 countries in the Americas and Africa.

The last known case of local transmission of Zika on the US mainland was in 2017, with two cases in Florida and five in Texas, officials said.

Zika can cause a rash, headaches and muscle aches but is particularly dangerous to pregnant women because it has been proven to cause birth defects, including structural damage to the fetus's brain, eyes and nervous system.

The virus can be spread by mosquitoes and also by sexual contact.

Women who are pregnant are urged to stay away from areas where Zika transmission is ongoing, and men who have been exposed are advised to wait three months before attempting to conceive with a partner.

"The Zika story is not yet over. We are still learning more every day about the full impact of these infections," said Honein.

Explore further: Infectious diseases: Zika virus cases lower, but virus remains a risk

Related Stories

Infectious diseases: Zika virus cases lower, but virus remains a risk

August 6, 2018
The number of reported Zika virus cases is much lower so far this year than at this point in 2017. However, pregnant women remain advised not to travel to areas where there is a risk of contracting the virus.

Zika birth defects in 5 percent of infected women in US islands

June 8, 2017
Five percent of women in the US territories who were infected with the Zika virus while pregnant had fetus or babies with defects, including microcephaly, government health data said Thursday.

CDC: Puerto Rico may see hundreds of Zika birth defects

June 17, 2016
Dozens or hundreds of babies in Puerto Rico could develop severe birth defects because of Zika, based on how an outbreak is playing out there, a top U.S. health official said Friday.

Zika linked to birth defects in six US cases

June 17, 2016
The Zika virus has been linked to birth defects in the fetuses and babies of six women in the United States who were infected while pregnant, US health officials said Thursday.

Puerto Rico reports 1st death from paralysis linked to Zika

August 19, 2016
Puerto Rico is reporting its first death from a paralysis condition that developed from a Zika infection.

Puerto Rico receives $2M to fight Zika epidemic in mountains

December 29, 2016
Puerto Rico has been awarded more than $2 million in federal funds to fight Zika across mountain communities in the U.S. territory's interior.

Recommended for you

New hope for cystic fibrosis

October 19, 2018
A new triple-combination drug treatment being trialled at the Mater Hospital in Brisbane could increase the life expectancy of patients with cystic fibrosis.

Bug guts shed light on Central America Chagas disease

October 18, 2018
In Central America, Chagas disease, or American trypanosomiasis, is spread by the "kissing bug" Triatoma dimidiata. By collecting DNA from the guts of these bugs, researchers reporting in PLOS Neglected Tropical Diseases ...

Rapid genomic sequencing of Lassa virus in Nigeria enabled real-time response to 2018 outbreak

October 18, 2018
Mounting a collaborative, real-time response to a Lassa fever outbreak in early 2018, doctors and scientists in Nigeria teamed up with researchers at Broad Institute of MIT and Harvard and colleagues to rapidly sequence the ...

Researchers cure drug-resistant infections without antibiotics

October 17, 2018
Biochemists, microbiologists, drug discovery experts and infectious disease doctors have teamed up in a new study that shows antibiotics are not always necessary to cure sepsis in mice. Instead of killing causative bacteria ...

Infectious disease consultation significantly reduces mortality of patients with bloodstream yeast infections

October 17, 2018
In a retrospective cohort study conducted at the University of Alabama at Birmingham Division of Infectious Diseases, patients with candidemia—a yeast infection in the bloodstream—had more positive outcomes as they relate ...

How drug resistant TB evolved and spread globally

October 17, 2018
The most common form of Mycobacterium tuberculosis (TB) originated in Europe and spread to Asia, Africa and the Americas with European explorers and colonialists, reveals a new study led by UCL and the Norwegian Institute ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.