West Nile Virus (WNV) in Alberta Horses (2003 to 2016)

Year Number of Confirmed Positive Cases Number of Possible Cases Number of Reactor Cases Number of Suspect Cases
2003 170 - - -
2004 4 - - -
2005 3 - - -
2006 9 - - -
2007 46 - - -
2008 0 - - -
2009 1 - - -
2010 0 - - -
2011 0 - - -
2012 5 - - -
2013 14 - - -
2014 6 - - -
2015 10 - - -
2016 10 - - -
2017 * 11 2 - 1
2018 73 5 1 2
TOTAL 362 7 1 3

As of * Revised Case definitions, as per the OIE, for equine cases of Wet Nile Virus in 2017.

** total only includes confirmed positive cases from 2017 onwards as per revised case definitions.

Cases Reported in 2018: As of October 22 2018, a total of 82 cases had been received, of these there are 74 positives cases
(1 for a Saskatchewan horse tested by an Alberta Vet) so 73 Alberta positive cases, 7 possible cases, 1 reactor and 2 suspect cases.

Case Distributions for 2018: The map below shows the locations of 71 cases that submission forms have been received for.

The Office of the Chief Provincial Veterinarian was notified of the first confirmed "possible positive" equine case of West Nile Virus in 2018 on Thursday July 19 in horse in the County of Mountain View.

For more information about WNV in horses, please read the WNV Agri-Fact sheet.