By David J. Berck, MD MPH | Maternal & Fetal Medicine
The images flooding the media are alarming: Babies with abnormally small heads – one of the most prominent birth defects resulting from Zika infection in their pregnant mothers – and destined to live with physical and mental impairments for the rest of their lives.
But how common is Zika, really? Transmitted primarily by infected mosquitoes or unprotected sex with someone who’s infected, the Zika virus only came to the forefront of public consciousness in the United States within the last year or so. As of the end of April, about 5,300 Zika cases had been reported in the U.S. in 2017, only 29 of which occurred from a mother passing the virus to her fetus.
Many of those infected with Zika never suffer any symptoms, however. In those who do, effects are usually mild and resolve completely, including fever, rash, joint pain or red eyes. But it’s in newborns that Zika can really wreak havoc – hence those images of babies with microcephaly, in which their brains don’t develop properly because their mothers were infected during pregnancy. Not all babies suffer such devastating consequences, however.
So if you’re pregnant or know someone who is, it’s natural to wonder: Who is most at risk, and when is Zika testing needed?
Who’s Most at Risk?
Few of those in the United States infected with Zika were actually infected while inside the United States. According to the U.S. Centers for Disease Control and Prevention (CDC), only South Florida and a small region in Texas thus far are “hot spots” where Zika-infected mosquitoes have been active.
The vast majority of Zika cases in Americans have been picked up during travel elsewhere. Zika “travel notices” – locations of higher risk – include Mexico, Africa, Asia, the Caribbean, Central America, the Pacific Islands and South America.
This means that pregnant women – who are able to contract Zika throughout the 9-month gestation – should not travel to areas with Zika infection risk, the CDC recommends. If you’re thinking of becoming pregnant, wait to do so if you’re anticipating traveling to any Zika-infected areas. Additionally, all pregnant women whose sex partners have lived in or traveled to a Zika advisory area should use condoms or avoid sex during their pregnancy, even if their partners exhibit no symptoms.
When Zika Testing is Advised
Specific circumstances dictate when Zika assessment or testing is advisable for a pregnant woman, according to the CDC. Assessment includes asking relevant questions about travel and potential exposure to another with Zika. Testing includes various lab analyses, such as tests of blood, urine and/or cerebrospinal fluid.
· All pregnant women in the U.S. and its territories should be assessed for possible Zika exposure.
· Pregnant women who have lived in or traveled to a Zika travel notice area should be tested, regardless of symptom status.
· Pregnant women whose sexual partner has lived in or traveled to a Zika travel notice area should be tested, regardless of their partner’s symptom status.
· Pregnant women who are symptomatic for Zika infection – including fever, rash, joint pain and red eyes – should be tested. The exact type of test ordered by your doctor will depend on the timing of evaluation compared to symptom onset.
There’s currently no vaccine to prevent Zika or treatment once it occurs. Pregnant women who test positive for the virus will likely be monitored by ultrasound more closely to track their baby’s development. But the odds of getting Zika while pregnant in the United States are exceedingly low. Follow the guidelines and be vigilant, but don’t panic.