What are the differences between West Nile neuroinvasive disease (WNND) and West Nile fever (WNF)?

The most severe type of disease due to a person being infected with the West Nile virus is called "neuroinvasive disease" because it affects a person’s nervous system. It is characterized by:

  • Disorientation
  • Headache
  • High Fever
  • Neck Stiffness
  • Stupor and Other Serious Symptoms

Symptoms can last weeks to months, and can even result in death. West Nile neuroinvasive disease (WNND) only infects approximately 1% of people who have been bitten by a West Nile fever (WNF) - carrying mosquito. West Nile fever is another type of illness that can occur in people who become infected with the virus. It is characterized by:

  • Aches
  • Fever
  • Headache
  • Tiredness and Sometimes Rash

Although the illness can be as short as a few days, even healthy people have been sick for several weeks. WNF infects approximately 20% of people who have been bitten by a WNF - carrying mosquito.

Show All Answers

1. What is West Nile Virus?
2. What are the differences between West Nile neuroinvasive disease (WNND) and West Nile fever (WNF)?
3. How long has West Nile Virus been in the U.S.?
4. How long has West Nile Virus been in Denton County?
5. How long is the West Nile Virus season in the U.S.?
6. What is the basic transmission cycle of West Nile Virus?
7. What is the incubation period in humans (i.e., time between bite from infected mosquito to appearance of symptoms) for West Nile disease?
8. How long do symptoms last?
9. I think I have West Nile Virus, do I need to report it to the Health Department?
10. I've been bitten by a mosquito. Should I be tested for West Nile Virus?
11. My doctor told me that I have West Nile Virus. How do I report it to the Health Department?
12. Can a human get the virus twice?
13. Is there a human vaccine?
14. What kind of laboratory tests are done to identify the West Nile Virus in humans?
15. How many human cases have there been in the United States? How many deaths?
16. How many human cases have there been in Texas? How many deaths?
17. What is the risk of someone becoming infected with West Nile?
18. In addition to being infected by the West Nile Virus, what else can cause bird "die-offs"?
19. Can dogs, cats and other pets get the West Nile Virus?
20. Is there a vaccine for dogs and cats?