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

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 the occupation and anything that can bring them in closer contact to mosquitoes and increase their likelihood of contracting something like West Nile virus."

He says other factors such as whether the person recently spent time at a cottage or campground are also considered in someone's claim for West Nile.

Fortin says the responsibility of the WSIB as an administrative tribunal is to examine all factors that have led to a person's exposure to a disease like West Nile and there is no burden of proof either for or against the worker's claim on either the WSIB or the claimant.

"Only once a lull investigation has occurred can a decision be made, but it must be based on all the information that can be gathered," she says. "It's an unfair assumption for us to be anything but fair and objective."

"The question we have to ask is, is it likelier than not that the exposure that person had has contributed to that person's condition," says Broad. "If the adjudicator is satisfied that this condition is met, then they will find favourably for that claim."

The WSIB will investigate any claim made by a worker, but it is up to the worker to provide all the information including work and medical history that the WSIB requires in assessing the validity of that claim.

Employers are urged to take all necessary precautions to protect workers from increased exposure, but employees also have a responsibility to protect themselves, says Perry Jensen, WSIB senior officer of information. Information for both employers and employees can be found at the WSIB's Web site www.wsib.on.ca.

In total, Fortin says that the WSIB receives between 11,000 and 12,000 disease claims annually, as well as an additional 7,000 to 8,000 "exposure" claims that can include infectious disease exposures every year.

Job-induced hearing loss is the most common claim to the WSIB, she says.