Just in time for the summer months and kids on summer vacation, there was a recent Illinois Department of Public Health (IDPH) memo that alerted healthcare providers and public health officials that West Nile Virus (WNV) activity in mosquitoes and birds is increasing throughout the state.  The current high summer temperatures and low rainfall in Illinois are providing favorable breeding conditions for the type of mosquitoes (Culex Pipiens and related species) that carry WNV.

Luckily, the majority of people infected with WNV will have no symptoms, however about 20% of people will develop a flu-like illness with fever, headache, nausea and muscles aches.  In rare cases, some people may develop an infection that involves the brain (e.g. meningitis or encephalitis) and death may occur in a subset of these individuals; people who are 50 years old and over are most at risk of severe complications from the disease.

So how does one avoid getting West Nile Virus?

Avoiding being bitten by mosquitoes that carry the disease will prevent getting WNV.  And this is where the three R’s, Reduce, Repel and Report come into play.

Reduce exposure to mosquitoes:

• Avoid being outdoors when mosquitoes are most active, typically dusk and dawn.
• Make sure doors and windows have tight-fitting screens.  Repair or replace screens that are damaged with tears or other openings.

Repel mosquitoes:

• When outdoors, try to limit the amount of skin that is exposed to mosquitoes; this means long pants and long sleeve shirts, especially at times that mosquitoes are active (i.e. dawn and dusk).
• CDC recommended repellants include DEET, picaridin, oil of lemon eucalyptus and IR 3535.  Products with higher concentrations of repellant do not necessarily provide more effective repellency, but instead provide a longer period of repellent action.  An example of this effect can be seen in a 2002 paper by Fradin and Day on the efficacy of DEET:
  • A product with 23.8% DEET provides about 5 hours of protection
  • A 20% DEET formulation provides almost 4 hours of protection
  • 6.65% and 4.75% formulations provide 2.0 hours and 1.5 hours of protection respectively

For all of the repellants, read the label instructions on how often to apply the product.

To ensure that that we all remain safe with insect repellants the EPA recommends the following guidelines.

• Apply only to skin or exposed clothing.  Do not apply underneath clothing.
• Do not use repellant on open wounds, cuts or irritated skin.
• Do not apply to eyes or mouth.  When using a spray, do not spray onto face, but instead spray onto hands and then rub onto the face.
• Use just enough to cover the exposed skin or clothing.  Heavy applications are usually unnecessary for effectiveness.
• After going indoors, wash off skin with soap and water.

Another form of repellant is special clothing impregnated with an insecticide called permethrin (a common ingredient in household insect killers).  They are available in outdoor gear stores and most often used in camping, fishing and other outdoor activities that involve long periods of time outdoors during high risk times of dawn and dusk.

Report areas where mosquitoes breed:

• In communities that have a mosquito control programs, report areas of stagnant water (roadside ditches, flooded backyards, etc) to the local municipal government.  These areas can be treated to reduce the number of mosquitoes that carry disease in your community.

During the summer we all want to have fun, play with our friends and families and revel in the beauty of each day.  A little bit of the three R’s will help keep us healthy so we can Relax (the best R of all) and enjoy a great summer season!

And remember, always call the Illinois Poison Center after ingestion or exposure to any potentially harmful substance, no question too big or small: 1-800-222-1222.

Until next Tuesday,