U.S. Areas With Zika Transmission See Uptick in Birth Defects
Given that Zika has been linked to serious birth defects including microcephaly, you’ve likely been extra-vigilant about skipping trips to areas with known local transmission of the virus and taken extra protections to avoid bug bites if you do live in an affected area — especially if you’re TTC or pregnant. For the most part, the U.S. has been spared from an outbreak of Zika-related birth defects on the scale of what’s happened in areas including Brazil. However, while rates here remain very low, a report from the Centers for Disease Control and Prevention (CDC) has found that areas in the U.S. with local Zika transmission saw a spike in birth defects in 2016.
What the report looked at
The CDC reviewed nearly 1 million live births in 2016, representing about a quarter of all babies born. They honed in specifically on 15 states and territories that had either local transmission of Zika or at least one report of confirmed, symptomatic Zika infection related to travel. These included select southern counties in Florida, select counties in Georgia, Hawaii, Iowa, Illinois, Massachusetts, New Jersey, New York (excluding New York City), some parts of North Carolina, Puerto Rico, Rhode Island, South Carolina and parts of Texas, Utah and Vermont. The report provides the first comprehensive data monitoring the prevalence of birth defects potentially related to Zika virus infection.
What it found
There were 2,962 infants and fetuses with birth defects potentially related to Zika virus infection in the U.S. in 2016, including 2,716 live births. That works out to about one in every 33 babies born in 15 states and territories with a birth defect possibly associated with Zika virus infection in the mother. That rate is actually close to Zika-related birth defects related to infections from 2013 and 2014, the authors note. However, this report expands their search by 12 regions, creating a better picture of the U.S. overall.
“To provide some context on the prevalence, about one in 691 babies has Down syndrome and about one in 940 babies has cleft lip with or without cleft palate,” says Peggy Honein, Ph.D., M.P.H., acting director at the CDC’s Division of Congenital and Developmental Disorders, National Center on Birth Defects and Developmental Disabilities.
In the last half of 2016, areas with local Zika transmission actually saw a 21 percent increase in births with outcomes likely linked to Zika compared to the first half of the year. These include southern Florida, a portion of south Texas, and Puerto Rico. Other areas saw an overall decrease in Zika-related birth defects.
Researchers say it’s unclear whether the birth defects actually had to do with Zika virus spreading locally. Most of the moms whose babies had Zika-like birth defects did not have evidence they were infected with Zika. For the vast majority, it was because they weren’t tested; others may not have been tested at the right time or may not have been infected.
“It is important to remember that while these birth defects are potentially related to Zika, these same birth defects also occur due to other causes and in the absence of Zika,” says Honein.
With that said, a Zika diagnosis is known to greatly increase the risk of birth defects.
“Although Zika-related birth defects in the population are pretty rare events, there is about a 20-fold increase in risk among pregnancies with laboratory evidence of Zika,” Honein says. “5 to 10 percent of women with laboratory evidence of Zika virus infection will have a baby with birth defects noted during the initial newborn period, and the full extent of disabilities in children resulting from Zika is not yet known. Some children without birth defects noted at birth are later diagnosed with serious problems.”
Among birth defects in babies:
- 49 percent were born with brain abnormalities and/or microcephaly (when the circumference of a baby’s head is much smaller than what’s considered normal)
- 20 percent had neural tube defects and other early brain abnormalities
- 9 percent had eye abnormalities without brain abnormalities
- 22 percent had nervous system damage, including joint problems and deafness, without brain or eye abnormalities
What this means for you
The CDC says their findings stress the importance of continuing to track birth defects possibly related to Zika in areas at risk of local transmission and exposure.
“Babies with Zika-related birth defects need all the help they can get, as soon as possible and for as long as they need it,” said CDC Director Brenda Fitzgerald, M.D. “This report highlights the critical importance of documenting birth defects possibly related to Zika and our need to maintain vigilance.”
Honein also notes the importance of reminding pregnant women and couples planning pregnancies to know that Zika remains a risk. She suggests that all expecting moms and women who are planning pregnancies should continue to take steps to protect themselves from Zika — specifically:
- Keep track of CDC travel alerts and follow all recommendations.
- If you’re currently pregnant, you and your partner should do your best to avoid traveling to areas with known risk of Zika. If you must travel, discuss your travel plans with a trusted health care provider first.
- If you’re planning to get pregnant, consider waiting at least six months after traveling to an area with Zika risk and talk with your practitioner about your travel and baby-making plans.
- If you do live in or have to travel to an area where the Zika virus is being transmitted, take extra steps to avoid bug bites: stay inside during peak mosquito hours (daytime for Zika); wear protective clothing, including long-sleeved shirts and pants, preferably treated with permethrin; use 10 percent DEET on exposed skin; sleep in screened or air-conditioned rooms.
Should I Get Tested for Zika?
If you’re pregnant , think you may have been exposed to Zika and you’re experiencing symptoms: Yes. The CDC recommends you get tested as soon as possible. Symptoms include:
- Red eyes
- Joint pain
- Pain behind your eyes
If you’re pregnant, have potentially been exposed to Zika and are asymptomatic: No. Currently, the CDC does not recommend that asymptomatic pregnant women who’ve potentially been exposed to Zika get tested. Why? As experts learn more about the virus, the risk of false positives increases, which can cause anxiety and fear.
One exception to this guideline: If you’re pregnant and asymptomatic, but you have potential repeated, ongoing exposure to the virus (for example, you regularly travel to a Zika-impacted area for work), the CDC recommends you get tested three times during your pregnancy.
The bottom line
Although the virus can be scary and confusing, we’re learning more about Zika every day (and researchers are hard at work on a vaccine). If you ever have any questions, don’t hesitate to talk to your doctor. He or she can talk you through any specific issues or fears you may have and determine whether testing is right for you.