Summer is the season of outdoor living, it is also the season of insects.  Dormant all winter the insect population explodes as the weather grows warmer and each month seems to have its own ‘specialty’ of the insect world.  Early summer brings black flies, no-see-ums and mosquitos, all pesky little biters that leave us swatting, scratching and running for long sleeve shirts and bug repellants. 

The past few years have added a new dimension to the trials and tribulations of flying, biting pests, West Nile virus (WNV).  This flavivirus (related to yellow fever and dengue fever) is carried in the blood and can be transferred between birds, some animals and people by mosquito bites.  Incubation period is 3-14 days after infection.  It is estimated by the Center for Disease Control (CDC) that only 20% of people bitten by an infected insect will develop a mild case of the virus.  Symptoms of a mild infection are flu-like including; mild fever, head and body ache, swollen glands (lymph nodes), eye pain and lack of energy.  CDC have also determined that it is only 0.75% of people, (1 in 150) who are bitten by an infected mosquito that may contract a more severe form of the virus, which can result in encephalitis or meningitis.  Symptoms of this more severe infection include; high fever, stiff neck, disorientation, stupor, tremors, convulsions, paralysis and coma.

In North America the CDC reports areas with the largest numbers of infections.  These include Illinois (884 cases with 64 deaths), Michigan (614 cases with 51 deaths), Ohio (441 cases with 31 deaths), Louisiana (329 cases with 25 deaths), and Indiana (293 cases with 11 deaths).  Ontario and Quebec are the hardest hit areas of Canada to date.

Children and WNV
Interestingly children are not affected by WNV in the same way as adults.  In a report from CP Wire by Cassandra Szklarski on June 12, 2003, Dr Lee Ford-Jones, an infectious disease specialist from the Hospital for Sick Children saidinfections of WNV are much less common and much milder in children with a very low risk of complication.  Dr. Ford-Jones said that warnings were wrong to single out children, who are also less susceptible to SARS and Hepatitis A.  Ford-Jones went on to say that the ability of children to develop immunity is why the infection rate is reducing in countries that have had WNV for years.  As the immune children become adults they have already developed immunity and are not affected by the virus, so the number of cases is going down in these areas.

Protection
All this brings us to the question, what can you do to protect yourself from WNV?  First is to get rid of mosquito breeding grounds in your environment.  Standing water in ponds, water barrels, ditches etc are the favourite place for mosquitos to lay eggs.  Government initiatives have included the spraying of toxic chemicals to kill larvae but we know from experience that insects rapidly develop immunity to our attempts at control.  Eliminate standing water as much as possible and where it can’t be eliminated add a few drops of Eucalyptus globules essential oil to the water.  This forms a thin film on the surface and when the larvae come up for air they inhale the eucalyptus and die.  I add 4 drops to my water barrels every third or fourth day (when it has evaporated) and have not had any problems giving this water to my vegetables and plants.

Human protection includes common sense.  Avoid going out in prime bug hours, early morning and evening, and wear light coloured, long sleeve shirts, long pants and socks.  Most organizations recommend insect repellants containing DEET but there are many health concerns associated with DEET as well.  CDC recommends using DEET repellant on your clothes and not your skin.  However many natural substances, including essential oils work extremely well as mosquito repellants.  In particular essential oils containing chemicals from the functional group aldehydes are very active against bugs.  They are also anti-viral.  Aldehydic oils have a lemony scent but do not come from citrus fruit.  Oils such as lemon eucalyptus, citronella (both Java and Ceylon types), melissa, catnip, lisea or may chang and others fall into this category.  Unfortunately these oils are very easy to adulterate or synthesize so be sure you are getting what you pay for.  Some of the aldehydic oils are also costly, melissa and catnip for instance, are two of the most expensive oils in the world retailing at $100.00 or more for just 5ml.  If  you are buying tcatnip and melissa oils for less be suspicious, the yield of essential oil per kilo of plant material is less than 1/100th of 1% which explains the cost.

Hybrid lavender, also called lavendin has proved effective on its own and in combinations with other essential oils.  Lavender and lavendin are both cooling to the body and lower body temperatures are less attractive to mosquitos.  Peppermint and some of the eucalyptus species will also cool the skin as will coconut oil used as a carrier oil.  Combining cooling oils and insect repelling oils will give you a good, effective blend that can be used all summer long on the whole family.  Dilute the essential oils in an appropriate carrier, you will need 10%-30% essential oils depending on your combinations and the severity of insects in your area. 

The best carrier oils are ones that do not easily penetrate the skin.  Coconut and sesame oils are cooling and have some natural sun protection factor but they are also rapidly absorbed into the skin so it is best to combine them with a second carrier like almond oil.  Sweet almond oil contains no lecithin making it difficult for the skin to absorb and so your bug repelling oils will stay on the surface of your skin longer, giving you better protection.  Acqua Vita’s blend, “Stop Moustique” contains essential oils of Java citronella for its bug repelling and anti-viral properties, lavendin to cool the skin and deter bugs, peppermint and narrow-leaf mint eucalyptus for cooling and a little lemon eucalyptus to round out the synergy, diluted in a base of almond and sesame oils.  Our clients have used this blend from Costa Rica to Australia, the wilds of Algonquin park to the Florida everglades, in fact the only place it didn’t work was Winnipeg, Manitoba, the mosquito capital of Canada.

Enjoy the summer and worry less about West Nile virus with a little help from Mother nature.