First human case of West Nile Virus in Hamilton this season

HAMILTON , ON - The City of Hamilton has received confirmation of the first local human case of West Nile virus (WNV) this season prompting the Medical Officer of Health to move the WNV risk from moderate to high.

City of Hamilton Public Health Services Environmental Health Division continues to see more West Nile Virus positive mosquitoes in the traps.

“The risk of being infected with West Nile virus exists locally. Please continue to take precautions to avoid illness spread by mosquitos. This includes applying insect repellent containing DEET or Icaridin, covering up, and to also remove standing water on your property to prevent mosquito breeding ... The risk of West Nile virus will drop once there is a heavy frost that reduces the number of mosquitoes.”

Dr. Bart Harvey, public health physician

The City of Hamilton continually assesses the risk for human illness as part of a comprehensive West Nile Virus surveillance and prevention program. The City continues larviciding treatments on city street catch basins, in addition to ongoing treatment of surface waters on public land.

While most people infected with West Nile virus will have no symptoms (approximately 80 per cent), others including older adults or those with weakened immune systems may experience West Nile fever (~20 per cent) or they may develop more severe illness including inflammation of the brain or the lining of the brain (~1 per cent). For any infection, if symptoms do occur, they appear two to 14 days after being bitten by an infected mosquito. 

Avoid being bitten by mosquitos:

• Use a mosquito repellent (bug spray) containing DEET or Icaridin.
• Avoid areas where mosquitoes are known to be present, or cover up by wearing light coloured long sleeves and long pants when in mosquito areas such as wooded areas, on the golf course, or in the garden, especially at dawn and dusk when mosquitoes are most active.
• Reduce mosquito breeding sites by removing standing water at least weekly from your property

Additional Resources

• For additional information on West Nile virus visit www.hamilton.ca/westnile or call 905-546-2489.
• Hamilton’s Standing Water By-law
• Public Health Ontario - West Nile Virus Surveillance