West Nile Virus
(WNV · West Nile Encephalitis)
In this condition factsheet:
Diagnosing West Nile Virus
Your doctor can take a sample of blood or spinal fluid and send it to a laboratory to determine if you have been infected with the West Nile virus. Your blood or spinal fluid will usually be tested for antibodies to the virus, a sign that you have been infected. Your doctor can also send samples to do other testing for the generic components of the West Nile Virus. Before the testing, your doctor will probably ask you questions to determine if you could have been exposed to mosquitoes carrying the virus in the first place. People who live in or travel to areas where the virus has been found are at risk of getting infected.
Treating and Preventing West Nile Virus
There is presently no specific treatment or vaccine available to prevent West Nile virus. Severe cases of West Nile virus are treated with supportive care in a hospital. This involves helping the body fight illness on its own, rather than treating the cause of illness directly. People infected with West Nile virus may receive intravenous (into a vein) fluids and breathing support (by ventilator). Scientists are working on developing a vaccine for West Nile virus.
In the absence of an available vaccine, experts are advising people to protect themselves against the virus by avoiding bites from mosquitoes. The risk of becoming infected with West Nile is greatest during mosquito season. In Canada, the higher-risk season is from mid-April to late September or October.
The following suggestions can help you avoid mosquitoes:
Use insect repellent
- Always read the product instructions and warnings – how much to use and how often to use it may differ depending on the age group.
- Use insect repellent on exposed skin and on clothing but do not spray it directly on your face.
- Wash your skin with soap and water once you no longer need protection.
Avoid mosquitoes
- Minimize time outdoors, or remain indoors from dusk to dawn when mosquitoes are most active.
- Eliminate stagnant water (including bird baths) or standing water on your lawn. Regularly (twice a week) drain rain barrels and/or cover with screens, drain swimming-pool covers, clean eavestroughs regularly, and drain flowerpots and planters. Keep wheelbarrows and wading pools overturned when not in use.
- Around your yard and lawn, immediately throw away lawn cuttings, raked leaves, and fruit or berries that fall from trees. Place them in sealed garbage bags. Turn over compost piles regularly, and remove dense shrubbery, where mosquitoes are liable to breed and rest.
- Ensure that door and window screens are secure and free of holes.
Wear protective clothing
- Wear light-coloured clothes, including long-sleeved shirts and pants.
- Use a mosquito net over a baby's crib, stroller or playpen when the child is outdoors if there is a risk of being bitten by mosquitoes. Otherwise, dress the infant in long sleeve shirts and long pants when in an area where mosquitoes are present.
Other prevention strategies
Insecticides that destroy mosquitoes at various stages of their development can also be used to control the mosquito population. Provincial and local health authorities are the only people qualified and responsible for determining whether pesticides should be used to prevent the spread of West Nile virus in a particular area. When such a decision is made, the public is warned in advance so they can take precautions and minimize exposure. The workers who carry out mosquito control programs are licensed by provincial authorities.
Mosquito development consists of 4 stages: eggs, larvae, pupae, and adults. Adult females deposit eggs in or around standing water. The eggs hatch into larvae, which continue to develop in the area they were deposited and eventually develop into adult mosquitoes.
Insecticides can either destroy mosquito larvae (larvicides) or kill adult mosquitoes (adulticides).
Larvicides have greatest effect early in the mosquito season (from May to July in Canada) and less effect after mid-August. They are sprayed on areas where mosquitoes typically deposit their eggs. Adulticides are sprayed on plants where adult mosquitoes are commonly found. In general, larvicides are preferred to adulticides because they have less of an impact on human health, other animals, and the environment. They also disrupt the mosquito life cycle before they become adults and move to other areas. Adulticides are usually used as a last resort in situations where a high risk of human infection with West Nile virus exists. Because adult mosquitoes are mobile, adulticides may need to be sprayed repeatedly to control the mosquito population.
Provincial health authorities take West Nile seriously. They are monitoring the spread of the virus and are developing methods to manage outbreaks effectively.
All material copyright MediResource Inc. 1996 – 2024. Terms and conditions of use. The contents herein are for informational purposes only. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Source: www.medbroadcast.com/condition/getcondition/West-Nile-Virus
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