When the mosquitoes come so does the risk of West Nile Virus. Authorities in various parts of North America are warning people to take precautions to avoid infection of the West Nile Virus, which can sometimes seriously affect human health.
In Ontario there has been one confirmed infection this year so far, a bird. Crows, ravens, magpies and blue jays are especially susceptible to infection and many die from West Nile Virus (WNV) infection.
The WNV is typically carried by mosquitoes that feed on infected birds. When the infected mosquitoes feed on humans they transmit the disease. Usually, human infection starts to take hold in the mid to late summer.
Most humans who become infected will not get very ill. However, if more humans are infected in a given year, the number of complications and eventual deaths rises. Last year 101 infected people died in Canada. The elderly and people with weakened immune systems are most at risk of health complications.
Whether or not people are in for a bad mosquito season this year is still unclear. Mosquitoes lay their eggs in stagnant water. If you can limit the number of places around your home for mosquitoes to breed you will be reducing your chances of being bitten. Some simple measures can make a massive difference:
— Remove all stagnant water around your home. At least once a week, empty water from flower pots, pet food and water containers, swimming pool covers, buckets, barrels and cans
— Make sure there are no discarded car tyres lying around
— Check under bushes and areas you may have overlooked for recipients which may collect water
— Make sure your rain gutters are cleaned out
— Expose as little of your skin as you can when you go out
— Try not to go out during dawn and dusk
— Use an insect repellent, max 10% DEET for kids, max 30% DEET for adults (do not spray repellent containing permethrin directly onto skin, spray it on clothing)
— Place netting over infant carriers when outdoors
— If you can, install a secondary mosquito window (it has a net)
According to the CDC (USA) ultrasonic devices are not effective in preventing mosquito bites. Neither is vitamin B.
Infection with West Nile Virus can be Asymptomatic (no symptoms), or can lead to West Nile Fever or Severe West Nile Disease.
Asymptomatic West Nile Virus Infection
4 out of every 5 infected people will show no symptoms at all – they do not get ill.
Symptoms of West Nile Fever
About 20% of infected people
— Headache
— Temperature (fever)
— Tiredness
— Body Aches
— Swollen Lymph Glands
— Vomiting
— Stomach rash, Chest rash or Back rash
— Dizziness (could mean illness is becoming more severe)
— Disorientation (could mean illness is becoming more severe)
West Nile Fever can last from a few days to several weeks. Even healthy people have reported being ill for several weeks.
Severe West Nile Disease (neuroinvasive disease)
About 1 in 150 infected people
Includes:
West Nile Encephalitis (brain inflammation)
West Nile Meningitis (lining of the brain and/or spinal cord inflammation)
West Nile poliomyelitis
— Headache
— High Fever
— Neck Stiffness
— Stupor
— Disorientation
— Coma
— Tremors
— Convulsions
— Muscle Weakness
— Paralysis
The incubation period in humans is from 2 to 15 days. This is the period from initial infection to disease symptoms.
Useful web sites:
—
—
— West Nile Virus Web Site For Kids
Written by: Christian Nordqvist
Editor: Medical News Today