It’s not just Zika: Other mosquito-borne illnesses
Posted Feb 3, 2016 03:17:05 PM.
This article is more than 5 years old.
It’s not just Zika – there are other mosquito-borne illnesses that should concern Canadians.
In fact, it would be fairer to say that Toronto residents have less to fear from Zika than they do from West Nile and the California Serogroup Viruses, which can cause encephalitis.
Because the Zika virus is typically found only in very warm climates, “mosquitoes known to transmit the virus are not established in Canada and are not well-suited to our climate,” the Public Health Agency of Canada said last week.
The agency went on to say that most people recover fully without severe complications, and hospitalization rates are low. The virus can cause a mild fever and rash, and other symptoms include joint pain, headache, pain behind the eyes and conjunctivitis (inflammation of the mucous membrane that covers the front of the eye and lines the inside of the eyelids).
The virus does pose a danger to pregnant women, because of its possible link to birth defects and brain syndromes.
However, Canadians are more likely to contract West Nile virus from a mosquito, or, in much lower numbers, to catch one of several viruses belonging to the California Serogroup.
West Nile
West Nile virus is presently the most medically important arbovirus (virus transmitted by a mosquito, tick or other arthropod) in North America, according to the Public Health Agency of Canada.
Toronto Public Health reports that last year, there were ten confirmed and one probable case of West Nile Virus in the city.
The majority of people infected with West Nile show no symptoms. About one in five people infected with it have symptoms which may include fever, headaches, nausea, vomiting and body aches these can be accompanied by a skin rash and swollen glands. Symptoms can last anywhere from a few days to weeks, Toronto Public Health reports.
About one in 150 people infected will experience serious symptoms including neck stiffness, extreme confusion, disorientation, muscle weakness, vision loss and numbness.
Click here for more on West Nile.
La Crosse (encephalitis)
La Crosse virus is the most common of the California Sergroup of viruses. While many of those affected can have no symptoms and some will experience a fever or mild febrile illness, it can cause fatal encephalitis (brain swelling).
Those who do see symptoms may experience the following:
- sudden onset of fever followed by stiff neck, lethargy, focal signs, nausea and vomiting
- irritability that can last for one to three days
- headache
- meningismus
- hyperreflexia (overactive or overresponsive reflexes)
- upper extremity monoparesis
- anorexia
- abdominal pain
- More serious symptoms such as seizures can occur
The Public Health Agency warns that children who recover from La Crosse encephalitis often have considerably lower IQ scores than average, and a high probability of having attention-deficit-hyperactivity disorder.
Snowshoe hare, Jamestown Canyon, and Trivittatus viruses also belong to the California Sergroup but they are less common.
Other viruses
In Canada, dogs can contract dog heartworm, and the Western Equine Encephalitis (WEE) affects horses. Mosquito-borne illnesses like malaria and dengue fever aren’t found in Canada, at least any more. There was a malaria outbreak in the 1820s and 1830s, but was eradicated due to DDT spraying.
Reduce the risk
The following tips can help Canadians both at home and abroard reduce their risk of contracting any mosquito-borne illness.
1) Cover exposed skin. When you are outside, wear long pants and loose-fitting shirts with long sleeves, socks and a hat. Try a mosquito net over your hat to protect your head and choose light-coloured clothing (mosquitoes are attracted to dark colours).
2) Use insect repellent. When you are outside, you should use insect repellents (bug sprays and lotions) that contain the chemicals DEET or Icaridin.
3) Get rid of standing water. Drain or dry off water in old tires (even tire swings), rainwater barrels, children’s toys, flowerpots and wading pools. Clean eavestroughs regularly to prevent clogs that trap water, tip fishing boats and gear onto their sides to drain and replace the water in outdoor pet dishes and bird baths at least two times a week.
4) Put screens on your windows and doors to keep mosquitoes out of your home.
Tips from the Government of Canada
