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West Nile Virus

What is West Nile Virus?

West Nile Virus (WNV) is a disease of birds.  Mosquitoes are WNV carriers that become infected when they feed on infected birds.  Infected mosquitoes can then spread WNV to humans and other animals when they bite.  There have been no documented cases of WNV spreading from person to person or animal to person.


 
How is West Nile Virus Spread?

In a very small number of cases, WNV also has spread through blood transfusions, organ transplants, breastfeeding and even during pregnancy from mother to baby.  West Nile Virus is not spread through casual contact such as touching or kissing a person with the virus.  Viruses are most likely to be spread during the warm weather months when mosquitoes are most active, usually beginning in the spring and lasting until the first hard frost.



What are the symptoms of West Nile Virus?

Most people who are infected with the West Nile virus will not have any type of illness.  It is estimated that 20% of the people who become infected will develop West Nile fever: mild symptoms, including fever, headache, and body aches, occasionally with a skin rash on the trunk of the body and swollen lymph glands.  Incubation:  usually 3 to 15 days.

The symptoms of severe infection (West Nile encephalitis or meningitis) include headache, hgih fever, neck stiffness, stupor, disorientation, coma, tremors, convulsions, muscle weakness, and paralysis.  It is estimated that 1 in 150 persons infected with the West Nile virus will develop a more severe form of disease.

All residents of areas where virus activity has been identified are at risk of getting West Nile encephalitis; persons over 50 years of age have the highest risk of severe disease.  It is unknown if immunocompromised persons are at increased risk for WNV disease.

Mosquitoes in North Carolina also carry:

  • Eastern Equine Encephalitis (EEE), a virus of birds usually found in eastern NC.  It may cause headache, muscle ache, seizures, coma and death.  There is a vaccine to protect horses.
  • LaCross encephalitis (LAC), a virus of small mammals like squirrels and chipmunks ususally found in the very western part of the state.  LAC usually causes mile flu-like symptoms.  Young children may experience seizure and coma.


How can I protect myself?

Protect yourself from West Nile and other mosquito-borne illessses by avoiding mosquito bites.  Use clothing and repellents to protect skin.  Use common sense -- read and follow repellent labels carefully. 

Mosquitoes need only a few days and a little water to breed.  Eliminate standing water - tip, drip, and drain trapped water. Monitor pet bowls, birdbaths, pools, water gardens and other outdoor containers for mosquito breeding.

Dead birds, especially crows, cardinals, blue jays, hawks and other raptors, may be a sign West Nile is present in your community. 


Where can I find more information?




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