WEST NILE VIRUS West Nile Encephalitis is a mosquito-borne disease that was first identified in the New York area in 1999.   "Encephalitis" means an inflammation of the brain and it can be caused by viral and bacterial infections, including certain viruses transmitted by some mosquitoes. West Nile encephalitis is an infection of the brain caused by West Nile virus, which is commonly found in Africa, West Asia, and the Middle East. Prior to 1999, it had never before been documented in the Western Hemisphere. West Nile virus is closely related to the St. Louis encephalitis virus that is routinely found in the United States. Both of these viruses belong to the genus Flavivirus and they cause diseases that are similar to one another. More information on West Nile Encephalitis can be found at the following sites: USACHPPM-Main West Nile Virus Surveillance Guide CY 2004 NARMC Guidelines for West Nile Virus Encephalitis Surveillance, Prevention and Control Commanding General's Cover Letter Guidelines Document     Appendix A - NARMC West Nile Virus Encephalitis Fact Sheet for Health Care Providers     Appendix B - WNV Encephalitis Surveillance Case Definitions     Appendix C - West Nile Virus Reporting Form - Human Suspect Or Confirmed Positive Cases     Appendix D - WNV Points of Contact USACHPPM Fact Sheets     Just the Facts .....West Nile Virus (04/2003)     Just the Facts .... Mosquito Control Around the Home (2000)     Just the Facts ... West Nile Virus and Horses (Sep 2001) (pdf) Links to other West Nile Virus/Encephalitis Sites     Maps of West Nile occurrences (2000)     Maps of West Nile Occurrences (2001)     Maps of West Nile Occurrences (2002)     Maps of West Nile Occurrences (2003)     New York State Department of Health     CDC Division of Vector-Borne Diseases     US Geological Survey