Mosquito-born diseases include West Nile Virus, Malaria, Dengue Fever, and Yellow Fever. Prevention is much easier than a cure for all of these. Young children react more strongly from bites - eyelid swelling and lymph node swelling (neck) is common. Adults develp an immunity to mosquitos over time. A few simple precautions should eliminate most bites.

  1. Clothing: Cover up by wearing long pants, long sleeves and netting. Stay away from black and white fabrics, which appear to attract the little critters. Wear light coloured clothing (I know this is contradictory, but true!). Wash clothes in non-scented soap and dry without scented dryer sheets or liquids. Wear loose-fitting clothing that covers as much of your body as possible. Tuck pants into your socks. Spray clothes with permethrin, which is good for a many weeks.
  2. Location: Kids should play in open sunny areas, not near gardens or trees.
  3. Time of day: The easiest method of preventing bites is to go indoors during prime mosquito biting hours -- dawn and dusk. They are also attracted to carbon dioxide.
  4. Screens and bed nets: Bed nets can be draped over a bed or cockpit and can be used where screens are not practical. Spraying nets or screens with permethrin is effective for about 6 months to kill mosquitoes on contact.
  5. Scents: Mosquitoes are attracted to perfumes so don't use scented skin or hair products.
  6. Skin: use repellents carefully (see below)
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No pesticide can be considered 100 percent safe, especially for children and pregnant women. Use them following all precautions only if you cannot avoid bites any other way.

  1. DEET:

    (N,N-diethyl-m-toluamide, also known as N,N-diethyl-3-methylbenzamide): The most effective chemical repellents contain DEET to repel mosquitoes, biting flies, barn flies, black flies, sand flies, ticks, bedbugs, and leeches. DEET contains tuolene, an organic solvent. It is absorbed through the skin with possible side effects of rash, hives, blisters, irritation, and burning. Swallowing DEET can be fatal!

    DEET is continually absorbed into the skin, and is too toxic for babies, young children or pregnant women. Use less than 10% DEET for children and under 30% for adults. Avoid applying to your face or cuts. High-dose repellents should be used with great care. Wash DEET off as soon you go indoors.

    If you don't want DEET in contact with your skin, it is safer to spray it on clothing in combination with an insecticide such as NIX. But in stronger concentrations, DEET can ruin polyester clothing as well as plastic sunglasses!

    Skintastic (7% DEET) is considered safe for children - their kids spray is under 5% DEET. Muskol spray is 24% (adults only), and Muskol SPF15 9% (children). Deep Woods Off is 95% which should be used with great care. Read the label and use the lowest concentration you need. Applying a lower strength but more frequently is safer.

  2. Newer DEET products:

    3M Ultrathon, tested by the U.S. military, is a controlled release product as cream (31%) or spray (23%). It works up to 12 hours, and is the equivalent to a 75% concentrate.

    Skedaddle from Littlepoint Corp. makes a controlled-release cream (6.5%) that works up to 4 hours and is approved for children.

    DEET Plus from Sawyer Products (17.5%) is effective against mosquitos up to 4 hours and other biting flies up to 12 hours. Sawyer Controlled Release 20% DEET lotion was recommended by Colleen from Whitby, Ontario, who had experienced itching from similar products.

  3. Mosquito Coils: Used to create smoke that kills mosquitoes, the smoke contains about 70 volatile organic chemicals including allethrin, phenol, benzene, tuluene and xylene. Animal studies show abnormal growth of skin cells, poor weight gain and lung damage. Do not use in enclosed or poorly ventilated areas!
  4. Eucalyptus Oil: The active ingredient in oil of lemon eucalyptus is a chemical called p-menthane 3,8-diol (PMD). Natrapel is a spray containing oil of lemon eucalyptus that repels mosquitos for up to 6 hours. Lemon eucalyptus or PMD should never be used on children under 3 years.
  5. picaridin/icaridin/KBR 3023: The U.S. EPA says 20% offer protection from mosquitoes and barn flies of about 5 hours. It does not appear to be as toxic as DEET and does not destroy plastics.
  6. Permethrin a synthetic derivative of the chrysanthemum plant, kills both mosquitoes and other biting insects on contact. It does not repel them. Permethrin applied to clothing, camping gear and tents repels and kills ticks, mosquitoes, and other arthropods. It remains effective after laundering. Tuck your pantlegs into boots and spray them both to protect your legs. Never apply it to skin, as it can affect your nervous system in high doses. (Permethrin pesticide (EPA)
  7. Neem oil: This natural oil from an Indian tree, provides protection from mosquitoes for many hours. Azadirachtin, from the seeds, repels and disrupts the growth and reproduction of many destructive insects. Both oil or azadirachtin are effective and safe in low doses.
  8. Other mosquito repellants: IR3535, Oil of lemon eucalyptus (OLE), Para-menthane-diol (PMD), 2-undecanone
  9. Natural mosquito repellents:

    Did you know that some simple garden plants repel mosquitoes? Simply grow your repellant plants and move them near your chair to repel the bugs. Basil in a pot on your outdoor table will repel mossies - lemon basil works best. Lavendar has lovely flowers in eary summer and also repel mosquitoes. It needs a sunny spot and can also be grown in a pot to move to your deck when needed. Citronella Grass (used in citronella candles) can be grown in a patio container in a sunny spot - close to your favorite chair. Rub the leaves of common Geraniums on your skin - citrosa geranium is called the "mosquito geranium".

    Barn swallows and tree swallows eat lots of mosquitoes. Encourage them to make a home in your yard by putting up nesting boxes 2 metres up with about a 3-cm hole. Bats eat up to their body weight in insects every evening! If you put up a Bat house, it needs to be installed at least 7 metres up in a tree.

    Citronella oil (0.10% derived from the the Cymbopogon winteratus can be used on clothing and skin to repel mosquitos, and has few side effects.

    Skin-So-Soft (Avon product), is a moisturizing lotion containing citronella, and is an effective repellent for normal use. Note that citronella also repels dogs and cats!

    Lemongrass oil also provides good protection from mosquitos.

    Mozi-Q is a chewable tablet containing staphysagria, a natural substance that mosquitos and ticks seem to hate. It starts working in 30 minutes.

    Aromaflage is an Asian botanical that apparently doubles as a pleasant fragrance as well as an insect repellent - solving the problem of repelling everyone around you!

Folk lore: Biting insects are attracted to people who eat high-potassium foods (e.g. bananas, some sports drinks) due to the scent produced in their skin. Some people claim protection by taking vitamin B or garlic capsules. Others recommend mixtures of pennyroyal oil. (I have no idea is these work, just passing them on.)


Once the itch starts, people reach for first aid creams ending with -caine. The Old Farmer's Almanac says that onions have antimicrobial properties that reduce infections and promote healing, and they also contain sulfur which breaks down the bug venom.

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Mosquito-born diseases

  1. Malaria

    30,000 North Americans and Europeans contract malaria each year. In Canada 621 cases were reported in 1995, up 44% from 1994. You no longer need to travel to the Equator to get malaria. In 1996, a woman living in Toronto, who had not travelled and did not live near an airport, contracted malaria. [information reported in The Ottawa Citizen] It sure makes dock fever and two-footitis sound tame doesn't it?!

    Although rare in present-day Canada, malaria was a great danger to the men who worked to build the Rideau Waterway in the 1800's. Before the dams were built, the route was swampy and mosquoto infested.

    Anopheles quadramaculatus mosquito is the newest and most dangerous mosquito to come to North America. It can carry the protozoan that causes malaria and can spread dengue fever, yellow fever and encephalitis. They have a peculiar habit of doing a handstand as they bite. Scientists suspect this mosquito infected the woman in Toronto, since the normal summer biters do not carry these diseases.

    Anti-malarial drugs decrease the risk of contracting malaria, but it is not a 100% guarantee. 6-8 weeks before departure to a high-risk country, see your doctor, prefereably one who specializes in infectious diseases. Anti-maliaria medicine is taken 1 week before arriving in a high-risk area, during the stay, and for 4 weeks after leaving. The most dangerous type of malaria (falciparum) does not repond to the drug chloroquine anywhere except the Caribbean, Central America west of the Panama Canal and parts of the Middle East. In other areas malaria has developed drug resistance to this drug. You should always check with health authorities for the latest information about high-risk areas before travelling.

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  2. Dengue Fever

    Aedes albopictus mosquito carries viruses that spread dengue fever, yellow fever and encephalitis. They are different from other mosquitoes by attacking during daylight hours, feeding most aggessively at dawn and dusk. They will follow you into the house to continue feeding at night. This mosquite has spread northward each year and now lives and breeds in milder climates such as southern Ontario. The danger of a viral epidemic from this new breed is very real.

  3. Yellow Fever

    Aedes aegypti can transmit yellow fever. It has infested the U.S. sunbelt. Canadians travelling to Africa or South America should get vaccinated against yellow fever. In 1996, tourists who travelled to the Amazon died of yellow fever.