Medical Health Officer offers tips on West Nile virus prevention

“Just under 20 percent may have non-neurological syndrome (formerly known as West Nile fever). This is characterized by fever – you may have chills, nausea, vomiting, fatigue, you may have a rash, a headache. It’s almost an influenza-like illness, without the cough,” Suttorp said.

“Less than one percent can develop neurological syndrome. These symptoms can be quite severe. They can lead to meningitis, difficulty walking and muscle paralysis, unconsciousness and even death.”

Currently, there is no vaccine or specific antiviral treatments for a West Nile virus infection.

However, supportive treatments are available in severe cases. That can include pain medication, intravenous fluids and nursing care.

From 2003, to 2018, there were 532 cases of West Nile virus confirmed in Alberta.

According to AHS, many of those were acquired in the province and not related to travel. Of all those cases, 458 were non-neurological syndrome.

PREVENTION

Suttorp said the main message AHS wants to put out to the public is how to prevent being bitten.

“The precautionary measures are basically for almost all individuals. So, trying to avoid outdoors when the mosquitoes are most active, at dawn to dusk. If you’re outside, wear long-sleeved clothing, pants, a shirt and a hat, (use) an approved insect repellent, except of course for children under six months of age. If there’s any standing water around your house, get rid of it or change it frequently,” she said.

“Sometimes we don’t think about those simple measures. Mosquitoes like to breed around water. If you have no standing water, there’s much less likelihood that you (will) have mosquitoes.”

Suttorp added that AHS monitor what they call ‘degree days’, which collects the averages between daytime temperature highs and nighttime highs to track some of the habits of mosquitoes.

“Then we look at certain temperature ‘degree days’ where this mosquito likes to breed. So, we haven’t hit that ‘degree day’ yet.”

She remarked that people who are most at risk are those who are taking immunosuppressant medications and are organ transplant recipients.

“I think it’s part of the immunosuppressing medication that people are on. They’re on medications that suppressed the immune system – so they’re not rejecting a transplant. That’s also preventing that immune system from being able to combat this infection.”

Individuals with a chronic disease are also at risk.

She said due to the nature of the disease, and a lack of major symptoms in some cases, there were likely many more incidents of West Nile virus that had just not been reported to Alberta Health Services.

“If 80 percent have no symptoms, we don’t know about those people and 20 percent have milder symptoms that go away – like headaches, fever, nausea, vomiting, maybe a rash – we don’t know about many of those, and there is no treatment,” she said.

“So, most of those symptoms will go away, but if we had 40 cases in the South Zone in 2018, we can almost extrapolate that there are many more out there who have had disease, but they weren’t reporting or had very mild symptoms.”

Further details on West Nile virus are available through Alberta Health Services’ website.

by Justin Goulet

Medical Health Officer offers tips on West Nile virus prevention

What's Happening