West Nile virus (WNV) is a viral illness you can get from a mosquito bite. Most of the time the illness is mild, but sometimes it can cause inflammation of the brain (encephalitis) or inflammation of the membranes that cover the brain and spinal cord (meningitis). The risk of severe infection is greatest for people who are over 70 years old or who have a weakened immune system.
Wild and domestic birds, mainly crows, carry the West Nile virus. Mosquitoes become carriers of the virus when they bite infected birds. You can then get the virus if you are bitten by an infected mosquito. There are no known cases people getting WNV directly from an infected bird.
The risk of West Nile virus is seasonal in the northern states of the US and usually starts in the spring. The peak time for infection is mid to late August. In milder southern climates, the infection may occur year-round.
The infection is not spread by normal person-to-person contact like touching, kissing, or caring for someone who is infected. It can be spread through blood transfusions and organ transplants. However, blood centers and hospitals screen for West Nile Virus in donated blood and organs. The virus might also be transmitted through breast milk. However, the risk of spread of the virus to the baby is believed to be very low. If you are breast-feeding and you have a WNV infection, the American Academy of Pediatrics and the CDC say that it’s OK to keep breast-feeding.
Often there are no symptoms. Children are more likely to have symptoms than adults. When symptoms do occur, they usually start 3 to 14 days after you are bitten by an infected mosquito. They are usually mild and last a few days. Symptoms may include:
When WNV affects the brain, symptoms may include:
Your child's healthcare provider will ask about the symptoms and your child’s medical history. Your provider will examine your child. Tests may include:
There is no medicine that cures West Nile virus. If your child’s symptoms are mild, they will usually go away on their own. In most cases you can care for your child at home. If the infection is serious, your child may need to stay at the hospital. At the hospital, your child may be given IV fluids, pain relievers, or other treatments.
Most people infected with WNV, including nearly all children, don’t get seriously ill, and they recover fully. Symptoms usually last 3 to 6 days, but they can last as long as several weeks or months.
If your child has a serious infection, your child may be sick for weeks or months. In the most serious cases, the nervous system or brain may be injured.
Here are some things you can do to take care of your child during the illness:
Follow your child’s healthcare provider's instructions. Ask your provider:
Make sure you know when your child should come back for a checkup.
WNV can be prevented by taking precautions to avoid exposure to mosquitoes: