West Nile virus and other mosquito-borne diseases surveillance in Canada: Annual edition 2019 (infographic)

What is the risk

• West Nile virus (WNV) is the leading cause of domestically acquired mosquito-borne diseases (MBDs) in Canada

Who's at greater risk

• Advanced age and people with underlying medical conditions such as diabetes, cancer, and heart disease are at greater risk of WNV neurological syndrome

How to manage

• There is no specific treatment or vaccine for WNV
• Patients are treated for their symptoms

West Nile virus transmission

• Birds that are infected with WNV can spread the disease to the mosquitoes that bite them
• These mosquitoes then spread the virus to humans, animals and back to bird populations
• Only birds and mosquitoes can carry on the cycle of WNV
• Humans and animals cannot spread the virus to other humans or animals

Facts reported in 2019

• 45 positive dead wild birds
• 96 positive mosquito pools
• 8 positive horses
• 45 human cases acquired within Canada:
  • 41 clinical cases
  • 4 asymptomatic cases
• 8 travel-related human cases acquired outside of Canada or travel location not specified
• When compared to the average of the previous 5 years, a lower number of human cases was observed in 2019
  • Recurring fluctuations in the number of WNV human infections from year to year are not unexpected

Other Mosquito-borne diseases

• 18 human infections of California serogroup viruses
• 7 horses tested positive for Eastern equine encephalitis virus

Public health recommendations

Avoid becoming infected with WNV and other MBDs by:

• Protecting yourself:
  • cover exposed skin
  • use insect repellent with DEET or Icaridin
• Reducing surrounding risk:
  • eliminate standing water
  • maintain window and door screening