West Nile Virus and other Mosquito-Borne Diseases Surveillance in Canada: Annual edition 2018 (infographic) 

Organization: Public Health Agency of Canada

Date published: 2020-04-03

Related topics

• Surveillance of West Nile virus
• West Nile virus and other mosquito-borne diseases surveillance report: Annual edition (2018)

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 pre-existing 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.

WNV 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 2018

• 170 dead wild birds tested positive for WNV.
• 571 mosquito pools tested positive for WNV.
• 123 horses tested positive for WNV.
• A higher number of WNV-positive birds, mosquitoes and horses were observed when compared to the previous 5 years.
• 432 humans tested positive for WNV in Canada:
  • 29 people died from WNV infection.
  • 238 people suffered neurological illnesses.
• The reported number of WNV-positive humans (probable and confirmed diagnoses) in Canada has continuously risen since the year 2014.
  • slight decline in the number of reported cases between 2013 and 2014

Other MBDs

• 72 human cases of California serogroup viruses (CSGV) were detected in Canada.
• 13 horses tested positive for Eastern equine encephalitis virus (EEEV) in Canada.

Public health recommendations

• Avoid becoming infected with WNV and other MBDs by:
  • Protecting yourself:
    • cover exposed skin.
    • use insect repellent.
  • Reducing surrounding risk :
    • eliminate standing water.
    • maintain window and door screening.