The recent discovery of the potential harm to infants exposed to Zika virus has reawakened the awareness of insect-borne diseases. Besides Zika, there are many other diseases spread by insect bites. These include malaria, yellow fever, Lyme disease and West Nile virus among others. Also, insects other than mosquitoes can be involved in the spread of disease. Some examples are ticks, lice, fleas and some species of flies.

As a result, our clients are increasingly asking us about effective ways to prevent insect bites.

The first method that comes to mind is the use of insect repellents while pregnant. None on the market have been shown to be harmful to the developing fetus. Remember that the diseases you are trying to prevent are harmful to the fetus.

Note that higher concentrations are not more effective but do last longer. DEET at 30% and Picaridin at 20% will give 4-6 hours of protection on average.

A Few Facts About Insect Repellents


  • For many years the gold standard in insect repellents
  • Has been on the market since 1946
  • Has been used billions of times by millions of people
  • Appears to be the most effective at repelling ticks
  • Rare case reports and some animal studies have hinted that it might be harmful to the nervous system, but it is not confirmed in huge studies and is still felt to be safe when used as directed
  • Can leave an oily feel on the skin and may have an unpleasant odor
  • At higher concentrations can melt some plastics and fabrics


  • Introduced in Europe and Australia in 1998 and the U.S. in 2005
  • A synthetic product similar to those found in pepper
  • As effective as DEET but without the oily feel, unpleasant odor or tendency to melt plastic
  • Its relative newness on the market means that it has not had the years of research that DEET has

Natural products like Citronella, Eucalyptus oil and some Avon products

  • Effective, but only for short periods; approximately 1 hour
  • Not practical for use other than for a backyard barbeque

Do not forget these other methods of protecting against insect bites:

  • Wear long sleeves and long pants
  • Stay indoors with screened windows and/or air conditioning
  • Avoid places where mosquitoes breed
  • Spray or soak clothing and bed nets with Permethrin

Note that Permethrin is not an insect repellent but a natural insecticide and is comprised of a chemical similar to those found in Chrysanthemums and is used routinely in countries where malaria and yellow fever are found.

Safe travels…until next time