A new map shows mosquitoes that can carry the Zika virus are found in 40 states and Washington, D.C. (see below) Of most concern is Aedes aegypti, a tropical mosquito that carries not only Zika, but yellow fever, dengue and chikungunya. It thrives in urban areas and lives close to people.
In the past 10 years epidemics of dengue and chikungunya have swept through Latin America and the Caribbean. Dengue’s also been seen in Hawaii. Now Zika’s doing the same thing, and has also hit the U.S. territories of Puerto Rico and the U.S. Virgin Islands.
What we know
- No vaccine exists to prevent Zika virus disease (Zika).
- Prevent Zika by avoiding mosquito bites (see below).
- Mosquitoes that spread Zika virus bite mostly during the daytime.
- Mosquitoes that spread Zika virus also spread dengue and chikungunya viruses.
- Prevent sexual transmission of Zika by using condoms or not having sex.
Steps to prevent mosquito bites
When in areas with Zika and other diseases spread by mosquitoes, take the following steps:
- Wear long-sleeved shirts and long pants.
- Stay in places with air conditioning and window and door screens to keep mosquitoes outside.
- Take steps to control mosquitoes inside and outside your home.
- Sleep under a mosquito bed net if you are overseas or outside and are not able to protect yourself from mosquito bites.
- Use Environmental Protection Agency (EPA)-registered insect repellents with one of the following active ingredients: DEET, picaridin, IR3535, oil of lemon eucalyptus, or para-menthane-diol. Choosing an EPA-registered repellent ensures the EPA has evaluated the product for effectiveness. When used as directed, EPA-registered insect repellents are proven safe and effective, even for pregnant and breast-feeding women.
- Always follow the product label instructions.
- Reapply insect repellent as directed.
- Do not spray repellent on the skin under clothing.
- If you are also using sunscreen, apply sunscreen before applying insect repellent.
- To protect your child from mosquito bites:
- Do not use insect repellent on babies younger than 2 months old.
- Do not use products containing oil of lemon eucalyptus or para-menthane-diol on children younger than 3 years old.
- Dress your child in clothing that covers arms and legs.
- Cover crib, stroller, and baby carrier with mosquito netting.
- Do not apply insect repellent onto a child’s hands, eyes, mouth, and cut or irritated skin.
- Adults: Spray insect repellent onto your hands and then apply to a child’s face.
- Treat clothing and gear with permethrin or purchase permethrin-treated items.
- Treated clothing remains protective after multiple washings. See product information to learn how long the protection will last.
- If treating items yourself, follow the product instructions carefully.
- Do NOT use permethrin products directly on skin. They are intended to treat clothing.
Even if they do not feel sick, travelers returning to the United States from an area with Zika should take steps to prevent mosquito bites for 3 weeks so they do not spread Zika to mosquitoes that could spread the virus to other people.
Map showing the reported occurrence of Ae. aegypti by county between 1 January 1995 and March 2016 in the United States. Counties shown in yellow had Ae. aegypti presence records for 1 year within the specified time period, those shown in orange had 2 years of presence records within the specified time period, and those shown in red had 3 or more years of presence records within the specified time period. CDC/ Journal of Medical Entomology