CDC Releases Report on U.S. Zika-Associated Birth Defects
The Zika virus dominated headlines last spring and summer, after a link was discovered between the mosquito-borne disease and microcephaly, a condition where babies are born with abnormally small heads. (It can cause brain damage, developmental delays, and even death.) Now, a comprehensive new report from the Centers for Disease Control and Prevention (CDC) says one in 10 pregnancies from confirmed Zika cases in the United States resulted in the baby being born with birth defects.
Last year's Zika fears grew after the CDC announced that Zika virus can also be sexually transmitted. While the disease was largely reported in certain South American countries and the Caribbean at the time, the World Health Organization called Zika a global health emergency and predicted that it would spread throughout South America, Central America, the Caribbean, and North America. (The WHO ended the emergency designation in November.) Research also later linked Zika with Guillain-Barre syndrome, a disorder that leaves people unable to move.
But after the summer (and the end of mosquito season in most of the country), news about Zika largely dried up. There were a few reported cases of the disease being locally transmitted—meaning, people contracted it after being bitten by mosquitos in their area—in Florida and Texas, but it wasn’t quite the mosquito-led apocalypse that everyone was expecting.
Zika infection in the first trimester poses the highest risks for babies.
The CDC's new report looks at data collected from January 15 to December 27, 2016 by the CDC's U.S. Zika Pregnancy Registry. During that time, 1,297 pregnant women in 44 states were reported to the registry for possible recent Zika virus infection (the mom had either traveled to a Zika-infected area, or her partner had).
Of the 972 babies that were born, Zika virus-associated birth defects were reported in 51 of them, or 5 percent of the babies. That number got more alarming when researchers specifically looked at women who contracted Zika in their first trimester—15 percent of those babies reportedly had birth defects. Birth defects included brain abnormalities (which may or may not have included microcephaly), eye abnormalities, central nervous system dysfunction, neural tube defects (which can cause spina bifida, among other conditions), and other early brain malformations.
The link between a woman being infected in the first trimester and a 15 percent risk of birth defects is no accident, Richard Watkins, M.D., an associate professor at Northeast Ohio Medical University and an infectious diseases specialist in Akron, Ohio, tells SELF. While fetuses are always developing in utero, the first trimester is a crucial time for a fetus’ organ development, and infection during that time “will cause the most damage,” he says.
There were limitations to the CDC's report, though, most notably that only 25 percent of the babies in the data set underwent brain imaging, so the number of impaired infants could be higher. The researchers also pointed that they had limited data on other maternal risk factors for birth defects (such as genetic or other infectious causes), which might be causal factors for some of the birth defects they reported.
Zika infections were linked to birth defects even when moms didn't have any symptoms.
Zika infections cause symptoms, including a rash and fever, in just 20 percent of patients, while 80 percent of those infected with the disease have no symptoms—and the study found that the disease caused birth defects in women regardless of whether they experienced symptoms. CDC study authors noted that pregnant women with symptoms were more likely to be tested than asymptomatic women.
The findings confirm why experts warned us to be prepared.
The 51 cases of birth defects were traced to Zika acquisition outside the United States (though some of the women in the study were infected by mosquitoes in the continental United States). “We knew that there was a lot of travel and exchange of people between the United States and areas where Zika is widespread—the fact that we’ve got infections all over the United States is not surprising given travel patterns. It’s what we expected and prepared for," Amesh A. Adalja, M.D., a board-certified infectious disease physician and an affiliated scholar at the Johns Hopkins Bloomberg School of Public Health Center for Health Security, tells SELF.
The study's findings point to a glaring fact: Doctors were right to be worried about the risks of Zika virus for babies—and they’re not shocked that their predictions came true. “I am not surprised because the findings are similar to what has been reported in other countries with Zika virus cases,” Dr. Watkins says.
Adalja says Zika is “definitely” as dangerous as doctors had warned. In the beginning of last summer, there were a lot of questions about whether there was just a link between microcephaly and Guillain-Barre syndrome and Zika or if Zika actually causes those conditions. “Some of our worst fears regarding Zika have been proven," he says.
You don't have to avoid getting pregnant, but do take precautions if you're going to Zika-infected areas.
After reading this, you might be tempted to put your plans to have a baby on hold, but know this: The CDC currently recommends that women wait eight weeks after symptoms of Zika virus occurred to try to get pregnant, and that men wait six months after symptoms first appeared to have unprotected sex. (If you travel to a Zika-infected country or live in an affected area and suspect you may have contracted Zika, but don't have symptoms, it’s also considered best to follow those timelines, starting from the time you suspected that you were infected.)
But that doesn’t mean you shouldn’t avoid trying to get pregnant out of fear. “If you live in an area where there is not active transmission of Zika or you or your partner haven’t recently traveled to a Zika-infected area, you should be OK,” Dr. Adalja says. Dr. Watkins agrees. “I would advise women it is OK to get pregnant but they should take active steps to avoid mosquito bites,” he says.
Texas and Florida are the only states that reported local transmissions of Zika, and the CDC advises pregnant women avoid travel to Brownsville, Texas, and Miami-Dade County in Florida.
Regardless of where you live, if you're already are pregnant, take steps to avoid mosquito bites whenever possible. That includes trying to avoid going outside at dusk and dawn—times when mosquitos bite the most—and regularly wearing mosquito repellent. The CDC advises that pregnant women can use any repellent registered with the Environmental Protection Agency, including those that contain picaridin (a synthetic compound), IR3535 (a biopesticide), and DEET. “The EPA does not recommend any additional precautions for using registered repellents on children or on pregnant or lactating women,” the CDC states on its website.
If you’re worried that you may have contracted Zika, talk to your general physician. If testing is needed, he or she will contact your local health department to coordinate samples and testing, according to the (CDC)[https://www.cdc.gov/zika/pdfs/what-happens-tested-for-zika.pdf]. (If the health department isn't certified, the samples are shipped to the CDC.) And, while you shouldn’t panic over Zika, you should be aware of the risks associated with it. “Although there are not as many stories about Zika in the news, it is still a dangerous infection and people—especially pregnant women or those planning to become pregnant—need to be aware of it and take precautions,” Dr. Watkins says.
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