If I have West Nile Fever, can it turn into West Nile encephalitis?
When someone is infected with West Nile virus (WNV), they will typically have 1 of 3 outcomes: no symptoms (most likely), West Nile fever (WNF in about 20% of people) or severe West Nile disease, such as meningitis or encephalitis (less than 1% of those who get infected). If you develop a high fever with severe headache, consult your health care provider. WNF is typically a mild disease in people, characterized by symptoms such as fever, body aches, headache and sometimes swollen lymph glands and rash. WNF generally lasts only a few days, though in some cases symptoms have been reported to last longer, even up to several weeks. WNF does not appear to cause any long-term health effects.

There is no specific treatment for WNV infection. People with WNF recover on their own, though symptoms can be relieved through various treatments (e.g. medication for headache and body aches, etc.). Some people may develop a brief, WNF-like illness (early symptoms) before they develop more severe disease, though the percentage of patients in whom this occurs is not known.

Occasionally, an infected person may develop more severe disease such as "West Nile encephalitis," "West Nile meningitis" or "West Nile meningoencephalitis." Encephalitis refers to an inflammation of the brain, meningitis is an inflammation of the membrane around the brain and the spinal cord and meningoencephalitis refers to inflammation of the brain and the membrane surrounding it. Although there is no treatment for WNV infection itself, the person with severe disease often needs to be hospitalized. Care may involve nursing IV fluids, respiratory support, and prevention of secondary infections.

This information obtained from Los Angeles County West Vector Control and Centers for Disease Control and Prevention.

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1. What are the symptoms of West Nile virus infection?
2. What is the incubation period in humans (i.e., time from infection to onset of disease symptoms) for West Nile encephalitis?
3. How long do symptoms last?
4. If I have West Nile Fever, can it turn into West Nile encephalitis?
5. Has West Nile virus caused severe illness or death in horses?
6. How do the horses become infected with West Nile virus?
7. How does the virus cause severe illness or death in horses?
8. Can I get infected with West Nile virus by caring for an infected horse?
9. Can a horse infected with West Nile virus infect horses in neighboring stalls?
10. My horse is vaccinated against eastern equine encephalitis (EEE), western equine encephalitis (WEE), and Venezuelan equine encephalitis (VEE). Will these vaccines protect my horse against WNV?
11. Can I vaccinate my horse against West Nile virus infection?
12. How long will a horse infected with West Nile virus be infectious?
13. What is the treatment for a horse infected with West Nile virus? Should it be destroyed?
14. Where can I get more information on horses and West Nile virus?
15. Can West Nile virus cause illness in dogs or cats?
16. How can my veterinarian treat my cat or dog if they are/may be infected with WNV?
17. Does my dog / cat becoming infected pose a risk to the health of my family or other animals?
18. How do cats and dogs become infected with West Nile virus?
19. Can I become infected with WNV if a dog with the virus bites me?
20. Is there a vaccine for cats or dogs?
21. Should a dog or cat infected with West Nile virus be destroyed?
22. Can I use insect repellent on my pets?
23. Do birds infected with West Nile Virus die or become ill?
24. How can I report a sighting of dead bird(s) in my area?