By Glenn Wortmann, MD, director, Infectious Diseases, MedStar Washington Hospital Center
An April 2017 report from the Centers for Disease Control and Prevention (CDC) found that 1 in 10 pregnant women in the U.S. who contracted Zika virus in 2016 had a fetus or baby with Zika-related birth defects. News about this primarily mosquito-borne infection had died down some over the winter, but this report reminds us that the threat is not over.
Of the 5,238 Zika cases reported in the U.S. between Jan. 1, 2015, and April 19, 2017, 40 were in the District of Columbia. The vast majority of people picked up the infection during travel to an area with Zika, although a few cases were acquired through sexual transmission in the States. The virus made its way to the U.S. mainland in summer 2016, with infected mosquitoes found in Miami and Brownsville, Texas.
As the days get warmer and we once again begin shooing away mosquitoes, how concerned should D.C. residents be about Zika? While a local outbreak is not likely anytime soon, that doesn’t mean our community should ignore this serious infection. Let’s look at what we know, what we don’t, and how you can protect yourself, your partner and, potentially, your unborn child.
Zika-infected mosquitoes may not live in D.C., but we shouldn’t ignore the threat of #Zika virus. -Dr. Glenn Wortmann via @MedStarWHC
What we know about Zika
The Zika virus is primarily transmitted through the bite of an infected Aedes aegypti or Aedes albopictus mosquito. It can’t be spread through skin-to-skin or respiratory contact, such as a handshake or droplets from a sneeze, but it can be passed through unprotected sex.
The virus is not dangerous for most people. In fact, only one in five people infected will have symptoms, which can include:
- Conjunctivitis (red eyes)
- Muscle pain
Only 1 in 5 people with #Zika virus will have symptoms, but it can harm unborn babies. via @MedStarWHC
Zika poses the greatest danger to unborn children. When a pregnant woman is infected, Zika can cause birth defects such as microcephaly, in which a baby’s head and brain are unusually small. Microcephaly has been linked to problems such as seizures, developmental delays, hearing loss and vision problems. Zika also has been associated with miscarriage and stillbirth.
What we don’t know about Zika
While we’re learning more about Zika every day, we still don’t have firm answers to many questions.
So far, infected mosquitoes have been found only in small geographic areas of the U.S. While the potential range of Aedes aegypti and Aedes albopictus mosquitoes includes the D.C. area, it doesn’t mean that infected mosquitoes are guaranteed to come.
We know Zika can be spread through sex, but we aren’t exactly sure how long someone may be contagious. It appears that the virus can stay in semen longer than in other bodily fluids. Current guidance from the CDC for couples attempting to conceive is that women should wait at least eight weeks after the last possible exposure to Zika before trying to conceive, and that men should wait at least six months after the last possible exposure before trying to conceive. During this waiting period, couples should use condoms or not have sex.
It appears that Zika does the most harm to an unborn baby when contracted during the first trimester. But while it’s been shown that Zika can cause birth defects, we’re still learning about the range of birth defects it can cause. The effects of the virus may not be obvious at birth, or they may develop later. We’ll have to track these children over the years to learn exactly what damage this virus can cause.
There is no current treatment for Zika, but the good news is that researchers are working on a vaccine. Vaccine trials are underway, and I’m optimistic one will be approved in the next several years.
How to prevent Zika and other mosquito-borne infections
Right now, the best way D.C.-area residents can prevent contracting Zika is to avoid traveling to Zika-infected areas, especially if you are pregnant or planning to become pregnant. The CDC has a searchable map to check travel recommendations for Zika in a particular country. Find the map here.
Avoid travel to Zika-infected areas if you are pregnant or planning to become pregnant. via @MedStarWHC
If you must travel to one of these areas, talk to your healthcare provider. If you’re pregnant, the CDC recommends you be tested for Zika when you return, even if you don’t have symptoms.
Because Zika can be passed through sex, if your partner has been to a Zika-infected area, protect yourself by using condoms or dental dams and not sharing sex toys. Again, the CDC recommends women wait at least eight weeks and men wait at least six months before trying to conceive after possible Zika exposure or after symptoms start.
Zika isn’t the only disease spread by mosquitoes – West Nile virus is one of the most common mosquito-borne infections. No matter whether you travel to a Zika-infected area or relax in your backyard, take precautions to avoid mosquito bites:
- Use insect repellents that contain DEET. Follow the instructions when applying it to children.
- Wear long-sleeved shirts and long pants in the evening.
- Dispose of standing water around your house where mosquitoes can breed.
- Use screens on windows and doors, or sleep under a mosquito bed net if screens are not available.
Fortunately, Zika-infected mosquitoes have not been found in our community, nor are they expected to be soon. But that doesn’t mean we can let our guard down. By avoiding travel to affected areas and taking preventive measures if you or your partner must travel, we can keep our babies healthy and help slow the spread of this disease.