West Nile Virus Maps and Statistics

West Nile virus (WNV) was first found in Minnesota in 2002 and has since become the most commonly reported mosquitoborne disease in the state. The highest risk areas for WNV in Minnesota include the western and central portions of the state. Open areas, such as farmland and prairie, provide the best habitat for Culex tarsalis, the primary mosquito vector of the virus. Similar to other arboviruses, most WNV cases occur later in the summer when infected vector populations are at their highest level. 

In 2022, 22 WNV disease cases were reported in Minnesota. The majority of cases, 82%, reported symptom onset in August or September.

• 13 (59%) cases were male
• Median age was 66 years (range, 24 to 88 years)
• 17 (77%) cases were hospitalized 
• 17 (77%) cases had a severe illness affecting the central nervous system (encephalitis or meningitis) and one case died
• 4 WNV-positive blood donors who did not have any symptoms of illness were also identified
   

Maps and Graphs

• Reported Cases of West Nile virus disease in Minnesota by Year, 2002-2022 (PDF)
  Graph showing the number of reported cases of West Nile virus disease in Minnesota by year.
• Reported Cases of West Nile Virus Disease by County of Residence, in Minnesota (PDF), 2002-2022
  Map of reported cases of West Nile virus disease by county of residence.

Annual Summaries

• Arboviral Disease, 2019
  Minnesota Department of Health Disease Control Newsletter Annual Summary of Communicable Diseases Reported to the Minnesota Department of Health, 2019
  • Arboviral Disease, 2018
  • Arboviral Disease, 2017
  • Arboviral Disease, 2016
  • Arboviral Disease, 2015
  • Arboviral Disease, 2014
  • Arboviral Disease, 2013
  • Arboviral Disease, 2012
  • Arboviral Disease, 2011
  • Arboviral Disease, 2010
  • Arboviral Disease, 2009
  • Arboviral Disease, 2008
  • Arboviral Disease, 2007
  • Arboviral Disease, 2006
  • Arboviral Encephalitis, 2005
  • Arboviral Encephalitis, 2004
  • Arboviral Encephalitis, 2003
  • Arboviral Encephalitis, 2002
  • Arboviral Encephalitis, 2001
  • Arboviral Encephalitis, 2000

Archive of Maps

• 2021 - Minnesota Human West Nile Virus Monitoring (PDF)
• 2019 - Minnesota Human West Nile Virus Monitoring (PDF)
• 2018 - Minnesota Human West Nile Virus Monitoring (PDF)
• 2017 - Minnesota Human West Nile Virus Monitoring (PDF)
• 2016 - Minnesota Human West Nile Virus Monitoring (PDF)
• 2015 - Minnesota Human West Nile Virus Monitoring (PDF)
• 2014 - Minnesota Human West Nile Virus Monitoring (PDF)
• 2013 - Minnesota Human West Nile Virus Monitoring (PDF)
• 2012 - Minnesota Human West Nile Virus Monitoring (PDF)
• 2011 - Minnesota West Nile Virus Monitoring (PDF)
• 2010 - Minnesota West Nile Virus Monitoring (PDF)
• 2009 - Minnesota West Nile Virus Monitoring (PD)
• 2008 - Minnesota West Nile Virus Monitoring (PDF)
• 2007 - Minnesota West Nile Virus Monitoring (PDF)
• 2006 - Minnesota West Nile Virus Monitoring (PDF)
• 2005 - Minnesota West Nile Virus Monitoring (PDF)
• 2004 - Minnesota West Nile Virus Monitoring (PDF)
• 2003 - Map of counties with positive birds, horses and humans (PDF)
• 2002 - Map of counties with positive birds, horses and humans (PDF)
  • 2002 - Map of counties with positive horses (PDF)

National Statistics

• CDC: West Nile Virus Statistics & Maps
  Centers for Disease Control and Prevention.