‘Tis the Season to Protect Workers from West Nile


During the summer, heat stress isn’t the only safety hazard outdoor workers may face. Depending on the work they do, they may also be at risk of getting bit by mosquitoes and thus contracting the West Nile Virus.

Workers who work out in the field may be at risk of getting West Nile, including:

  • Farmers
  • Construction workers
  • Forestry workers
  • Landscapers and groundskeepers
  • Waste collectors and handlers.

The risk occurs during the mosquito season that starts as early as mid-April and lasts until the first hard frost in late September or October. But the risk is greatest when the mosquito species that are the primary virus-carriers, are most prevalent, active and biting, which is generally between mid-July to mid-September. In fact, most people get infected in late July and early August.

Many people who are infected with West Nile don’t have any symptoms. But others may develop either:

  • West Nile Non-Neurological Syndrome, which can have symptoms including headache, body aches, nausea, vomiting, skin rash and swollen lymph glands that usually resolve within 3 to 6 days
  • West-Nile Neurological Syndrome, a severe infection that can include headache, high fever, neck stiffness, stupor, disorientation, coma, tremors, convulsions, muscle weakness and paralysis.

A safety bulletin from Work Safe Alberta suggests that employers do the following if workers are exposed to mosquitoes on the job:

  • Have a plan for reducing the chances of workers getting bitten by infected mosquitoes (such a plan should include these six elements).
  • When scheduling work, avoid having workers work outdoors at dawn and dusk when mosquitoes are most active and minimize work near standing water when mosquitoes are most active.
  • Require at-risk workers wear light coloured, long-sleeved shirts, long trousers and socks. Wearing high boots and taping trouser legs is also recommended.
  • Have workers use insect repellent containing DEET or a similarly effective active ingredient on exposed skin.
  • Eliminate sources of standing water, such as stagnant pools, ponds, irrigation ditches and rain barrels, where mosquitoes like to lay their eggs.

At Safety Smart, you can get a safety talk for workers on West Nile and an article on an Ontario worker’s paralysis due to this virus.