West Nile Virus

West Nile Virus (WNV) is a mosquito borne viral disease. WNV occurs throughout the United States and can cause disease in humans, birds and other mammals. Many persons infected with WNV will have no obvious symptoms. In those persons who do develop illness, symptoms of WNV include: headache, high fever, altered mental state, tremors, convulsions and rarely paralysis. WNV can also cause meningitis/encephalitis and can be fatal. West Nile is transmitted to a person through the bite of an infected mosquito.

There is no specific treatment for West Nile virus. This disease is best prevented by avoiding exposure to mosquitoes.

Due to the recent positive West Nile virus pools detected in the state there has been a lot of discussion about dead birds.  From 2001-2006 as West Nile was emerging in the United States, Maine along with many other states tested dead birds for the presence of West Nile virus (WNV) and Eastern Equine Encephalitis (EEE) virus.  WNV and EEE were first identified in birds in Maine in 2001.  After 2006, Maine CDC determined that the virus was present in the state, and decided to discontinue dead bird testing.  Instead we shifted towards looking for active virus in mosquitoes, large animals, and humans.  While the bird testing was useful to document the movement of West Nile virus into Maine, we cannot always tell from the dead birds if they are actively infected or previously exposed.  Also because birds travel, we cannot tell where the bird acquired the infection.  These many factors combined led to our current approach, which does not involve individual dead bird reporting or testing.  However, if you find three or more dead birds all at the same time in the same place, that is something of interest to the state because it may indicate a die off( a sudden sharp decline of a population that is not caused directly by human activity).  Please report these die offs to Maine CDC at 1-800-821-5821.  Also if you have questions about West Nile virus in humans, or if you have questions about the surveillance we perform in the state, please call Maine CDC at 1-800-821-5821.

On this page:

Resources for Maine Residents

Resources for Physicians

  1. Arboviral Testing Form (PDF)
  2. HETL directions for Arboviral testing

Other Vector-borne Diseases

External Links