West Nile virus
What is West Nile virus?
West Nile virus is mainly spread to people through the bite of an infected mosquito. However, there have been a very small number of cases where the virus was spread by blood transfusion, organ donation, or from mother to baby during pregnancy, birth, or when breastfeeding.
Most people who get West Nile virus infection do not feel sick. For people who do feel sick, symptoms can include fever, headache, tiredness, nausea, vomiting, muscle aches, and a rash. Symptoms usually last from a few days to a few weeks.
Some people can have more serious disease. Adults over 60 years old or people with certain medical conditions are more likely to get seriously ill. Symptoms of serious West Nile virus disease include high fever, headache, neck stiffness, disorientation, coma, tremors, convulsions, muscle weakness, vision loss, numbness, and paralysis.
Who can get West Nile virus?
West Nile virus is found in countries throughout the world. Travelers going to Africa, Europe, the Middle East, west and central Asia, or North America can get West Nile virus.
The following activities can increase a traveler’s chance of getting infected:
- Spending a lot of time outdoors
- Traveling during times of the year when mosquitoes are more common, such as during the summer.
What can travelers do to prevent West Nile virus?
There are no vaccines or medicines that prevent West Nile virus. Travelers can protect themselves against West Nile virus infection by preventing mosquito bites.
Use insect repellent
- Use Environmental Protection Agency (EPA)-registered insect repellents with one of the active ingredients below. When used as directed, EPA-registered insect repellents are proven safe and effective, even for pregnant and breastfeeding women.
- Picaridin (known as KBR 3023 and icaridin outside the US)
- Oil of lemon eucalyptus (OLE)
- Para-menthane-diol (PMD)
Find the right insect repellent for you by using EPA's search tool.
- Insect repellent tips for babies and children
- Dress your child in clothing that covers arms and legs.
- Cover strollers and baby carriers with mosquito netting.
- When using insect repellent on your child:
- Always follow label instructions.
- Do not use products containing oil of lemon eucalyptus (OLE) or para-menthane-diol (PMD) on children under 3 years old.
- Do not apply insect repellent to a child’s hands, eyes, mouth, cuts, or irritated skin.
- Adults: Spray insect repellent onto your hands and then apply to a child’s face.
Wear long-sleeved shirts and long pants
Treat clothing and gear with permethrin
- Use 0.5% permethrin to treat clothing and gear (such as boots, pants, socks, and tents) or buy permethrin-treated clothing and gear.
- Permethrin is an insecticide that kills or repels mosquitoes.
- Permethrin-treated clothing provides protection after multiple washings..
- Read product information to find out how long the protection will last.
- If treating items yourself, follow the product instructions.
- Do not use permethrin products directly on skin.
- Watch the video What You Need to Know About Permethrin.
Keep mosquitoes out of your hotel room or lodging
- Choose a hotel or lodging with air conditioning or window and door screens.
- Use a mosquito net if you are unable to stay in a place with air conditioning or window and door screens or if you are sleeping outside.
Sleep under a mosquito net
- Sleep under a mosquito net if you are outside or when screened rooms are not available. Mosquitoes can live indoors and bite during the day and night.
- Buy a mosquito net at your local outdoor store or online before traveling overseas.
- Choose a mosquito net that is compact, white, rectangular, with 156 holes per square inch, and long enough to tuck under the mattress.
- Permethrin-treated mosquito nets provide more protection than untreated nets.
- Permethrin is an insecticide that kills mosquitoes and other insects.
- To determine if you can wash a treated mosquito net, follow the label instructions.
If you are bitten by mosquitoes, avoid scratching the bites and apply over-the-counter anti-itch or antihistamine cream to relieve itching. See Mosquito Bite Symptoms and Treatment.
If you traveled and feel sick, particularly if you have a fever, talk to a healthcare provider and tell them about your travel. Avoid contact with other people while you are sick.
If you need medical care abroad, see Getting Health Care Abroad.