This story was first published June 13, 2016; it was most recently updated April 5, 2017.
The Zika virus caused birth defects in about 10 percent of the 250 pregnant women confirmed by the to have contracted the virus, according to figures published April 4.
The virus, which is principally spread by mosquitoes, fueled public health anxiety last summer after initial reports of the birth defects in Brazil and as the disease spread north. Last year, it triggered a months-long debate in Congress, yielding a聽聽funding package聽to combat its spread.
Experts believe Zika, which is also sexually transmitted, could return to the United States聽this summer.
The numbers offer a preliminary window to understand the consequences聽of this disease 鈥斅爓hich previously had been the subject of little research 鈥斅燼nd how many people it affected last year. The CDC, which maintained a Zika Pregnancy Registry across 44 states, reported about 1,300 pregnancies faced possible infection last year.
In 2016, cases of the virus transmitted by mosquitoes were confirmed聽,听聽and Puerto Rico.
Women of child-bearing age are believed to be most at risk, although new research has suggested聽that more monitoring is necessary because some research has shown that symptoms may continue to emerge in 聽months after they are born. The virus has also been聽as a聽, an autoimmune disorder that causes temporary paralysis and can result in permanent nerve damage and even death. That tie has been supported by research on a 2013 Zika outbreak in French Polynesia and, more recently, by an examination published in the聽聽focused on both Zika and Guillain-Barre鈥檚 incidence in Colombia over the past year.
But looking beyond聽, what鈥檚 the real danger?聽Many doctors expect Zika to pose a renewed concern this coming summer, the peak season for mosquitos. Here鈥檚 a quick breakdown of the smart questions to ask and what we do actually know.
I鈥檓 a woman of childbearing age. What if I get Zika?
Most of the scariest headlines come from Zika鈥檚 potential to cause birth defects 鈥� the big one is , which severely impairs a child鈥檚 brain development. Zika has also been associated with miscarriages. But there are other for fetal and infant brain development, vision and hearing, scientists warn. Researchers also don鈥檛 know if babies born to mothers with Zika might, somewhere down the line, develop other health conditions, even if they appear healthy upon birth.
This risk should be greatest for women who are actually pregnant. But it鈥檚 not always immediately clear if someone has been infected. Symptoms don鈥檛 always emerge and, when they do, they often mirror the flu. So if there鈥檚 any chance you could conceive in the near future (and remember, almost are unintended), you should probably take precautions.
But getting Zika when pregnant doesn鈥檛 guarantee you or your child will have problems. An analysis聽聽in the New England Journal of Medicine found anywhere between 1 percent and 13 percent of pregnant women infected during the first trimester had children with microcephaly. New research suggests that risk may decline: A in the same journal followed a group of women infected in their third trimester, finding that none had children with the birth defect. But the researchers women letting down their guard until more follow-up is done on the topic.
So, here鈥檚 the short answer: The threat of birth defects or pregnancy complications is real. But it is not yet clear who will be affected and why.
I am pregnant. What steps should I take to protect myself?
There鈥檚 no cure or vaccine for Zika, and, according to the , if you鈥檝e been exposed, you will likely become immune. But that鈥檚 not known for sure.
Zika can be transmitted by mosquitoes and through sex. If you are pregnant, the best course of action is to avoid getting bitten. Minimize 聽and states where insects are spreading it. If Zika is detected where you live, the wearing long clothes that cover skin and using mosquito repellent.
Repellents containing compounds such as DEET or lemon eucalyptus are best and, if correctly used, shouldn鈥檛 pose a danger to pregnant women or fetuses. Peer-reviewed that claim.
What about sex? Zika can stay in semen for extended periods of time. If your partner traveled to an area where the virus is present, the 鈥� or at the very least, using a condom 鈥� for eight weeks. That figure goes up to six months if the man also developed symptoms of the illness. A research letter published in June in the described how Zika may be transmitted through oral sex. Separate research found it can be spread via . Some speculate the virus can even be transmitted by intense kissing, though evidence is scant.
If you aren鈥檛 pregnant but want to be, make sure you and your partner aren鈥檛 at risk 鈥� either by bites or sexual exposure 鈥� before trying to conceive.
I went somewhere where Zika-carrying聽mosquitoes聽have been detected, but I feel fine. Can I carry on as normal?
Even if you think you鈥檙e fine, take precautions. The problem is that most people with Zika won鈥檛 know they were sick. Only of people infected show symptoms. If there鈥檚 even a slight risk 鈥� say you traveled somewhere with active transmission or had sex with someone else who was exposed聽鈥� the CDC recommends before conceiving.聽Men, meanwhile, should wait longer. They should take precautions when engaging in sex for six months from either first symptoms or last possible exposure to the virus. The CDC put out that recommendation in September, based on developing information about how long the virus may remain in semen.聽If you鈥檙e sexually active, use effective birth control. Condoms can prevent semen-based transmission. An intrauterine device or the birth control pill will reduce the odds of pregnancy.
Those who show symptoms typically experience fever, a rash, conjunctivitis or aches and pains. If you are experiencing any of those and have reason to suspect Zika, see the doctor as soon as possible for a blood test. The odds of finding the virus are greatest in the first week of showing symptoms. After that, tests are , and they might show false positives if you鈥檝e been exposed to other viruses, like dengue, which is transmitted by the same mosquito and therefore also common in areas with Zika. It can also take weeks to hear back on Zika test results. Researchers are trying to develop better diagnostics, and efforts . For now, getting tested is the best option available.
If you test positive for Zika, and again recommend women wait two months before trying to get pregnant. (That鈥檚 a shorter wait period than the urged by other affected countries.) Meanwhile, take care of yourself. Rest up, drink lots of fluids and maybe take acetaminophen if you鈥檙e suffering aches or a fever. Ask your doctor for advice, too.
I have Zika, and I鈥檓 pregnant. What do I do?
This is the hard part. Your child won鈥檛 necessarily have a condition, but get in touch with an OB/GYN right away. Your doctor will likely advise regular ultrasounds, though microcephaly can鈥檛 be detected until the second trimester of pregnancy. A physician can counsel you on ways to reduce the threat of miscarriage 鈥� for which the risk is heightened with Zika 鈥� and help keep you up to date on treatments.
This is scary, and it鈥檚 a lot of information. How else can I stay up to date?
The science around Zika is constantly changing. Experts say the outbreak is revealing about the disease. To keep abreast of new developments, the CDC is your best bet: The agency has a fairly comprehensive Zika . The is another good resource. If you want to know what guidance your doctors are receiving, check out the.
This article was updated to add information from a June 15 New England Journal of Medicine study.