WSIB keeps close eye on West Nile virus: employers urged to take precautionary measures.

• Author: Wareing, Andrew
• Position: Construction: special report

The arrival of West Nile in Ontario has created another hazard for outside workers--the contracting of a potentially hazardous and sometimes deadly disease.

West Nile virus is a mosquito-borne illness that is primarily a bird disease, but has been known to cause problems for humans. At its mildest, there can be either no symptoms at all or mild flu-like symptoms.

At its worst, West Nile has been known to cause encephalitis, neurological problems and even death.

Claire-Marie Fortin, director of medical and occupational disease policy for the Workplace Safety and Insurance Board (WSIB), says the WSIB has not yet received any claims related to the disease affecting outside workers this year, but the agency is keeping a close eye on it.

"We can't predict what's going to happen this year," she says. "We don't know how effective precautions or employer measures to protect employees are going to be so it is really an unknown quantity right now.

"So far, this year, we've had a few reports of mosquito bites, but no West Nile virus claims," says Fortin.

Fred Broad, manager in the occupational disease and survivor benefits program for WSIB, says the agency is prepared to adjudicate every claim that comes in. Each will be assessed on a number of factors, including likelihood of exposure.

"We adjudicate West Nile virus claims similar to how we adjudicate workers who have similar exposures in their employment in that, what we are looking for is an exposure to a mosquito possibly carrying the West Nile virus and a condition diagnosed as West Nile virus," says Broad. "Those two conditions have to be met on a very fundamental level for someone to have entitlement."

Since West Nile is a disease that could be contracted in someone's back yard, Broad says that a number of factors are considered, including the person's usual exposure and whether their work increased the likelihood of coming into contact with West Nile.

"We need to look at whether the person works in the bush all day versus someone who works in an office. If both contract West Nile virus, then we'd have to have a look a lot closer at the person who worked in the bush versus the person who worked in the office," he says. "We look at the time of day they work. Are they working in the evening where there is an increased likelihood of contact? But the primary thing we're going to look at is...