West Nile virus Surveillance in Alberta

2018 West Nile virus cases

No cases of West Nile virus (WNV) have been reported so far in 2018.

  • In 2017, 7 cases were reported in Alberta: 2 neurological and 5 non-neurological.

Summary of cases 20032018

AHS Zone 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018
North 4 1 0 0 4 0 0 0 0 1 0 0 0 0 0 0
Edmonton 22 0 0 0 8 0 0 0 0 0 1 0 0 0 0 0
Central 45 0 0 0 25 0 0 0 0 1 3 0 0 0 1 0
Calgary 37 0 2 4 38 0 1 1 0 1 1 0 0 2 2 0
South 167 0 8 36 245 1 1 0 0 6 16 0 0 3 4 0
Alberta Total 275 1 10 40 320 1 2 1 0 9 21 0 0 5 7 0

There is a risk of WNV in Alberta every year. However, the risk varies depending on a number of factors:

  • the number of Culex mosquitoes that have successfully survived the previous winter,
  • the amount of WNV circulating in these same Culex mosquito populations,
  • weather conditions in the spring and early summer affecting the spread of WNV from mosquitos to birds and birds to mosquitos (amplification),
  • the proximity of human populations to WNV-infected mosquito populations.

Surveillance degree day maps

WNV degree day maps are one tool that assist health professionals in Alberta in determining the risk of WNV in Alberta each year.

Past surveillance summary reports

Surveillance in Canada and United States