Stay bug bite-free to avoid West Nile |

Stay bug bite-free to avoid West Nile

Dr. Drew Werner
Dear Doc
Vail, CO Colorado

Dear Doc,

I hate insect bites! I got eaten alive at Flight Days this weekend in Eagle and my mom said I should have worn insect repellant. Am I going to get West Nile Virus?

Itching in Eagle

Dear Itching,

First, you are not alone! Most of us hate those buzzing nuisances that seem to target us incessantly. Don’t lose any sleep, however. Enjoy all our local celebrations and our great outdoors. be smart and don’t worry! All right, I guess I need to say a bit more.

West Nile is an arbovirus to be exact. It was first identified in 1937 in Uganda – you guessed it, in the West Nile district. West Nile virus was recognized in Israel in 1957, in France in the 1960s and came to the U.S. in 1999. Best estimates are that it came via an infected bird to New York State. That same year, the first human case of West Nile virus in the U.S. was identified. It has adapted well to our country, and, by the summer of 2002, not only had it arrived in Colorado, but it actually reached California. It has been with us ever since, and likely is here to stay.

West Nile virus is transmitted by a mosquito bite, although not all mosquitoes carry the virus. Birds are the reservoir of infection. That is, they carry the infection, which is then transmitted to some annoying mosquito that has nothing better to do than bite us. The transmission of the virus is unnoticed. That means the reaction to the bite has nothing to do with the process of becoming infected. Any person may have a significant reaction to a harmless bite or no reaction to a bite which has infected them.

Several factors are important in the risk not only of being bitten, but of being infected. The outside temperature makes a difference. The hotter it is, the more likely an infected mosquito can transmit the virus. For that reason, the risks of West Nile virus begin now and increase through July, August and early September. The types of mosquito that carry the virus are active from dusk to dawn, so that is the key time to focus on prevention by staying indoors or wearing appropriate clothing and insect repellent outside. Nationally in 2010, only one human case of West Nile Virus has been confirmed – in Mississippi. Thankfully, there have been no deaths reported. West Nile activity has however been reported in nine states, including the nearby states of California, New Mexico and Texas. Now, then, is the time to begin our awareness, preparation and prevention.

So how can we get ready?

• If possible, eliminate any standing sources of water that might last for more than several days.

• Know that the infected mosquitoes are much more active between dusk and dawn.

• During times of greatest activity, avoid exposure or wear protective clothing when possible – long sleeves and long pants.

• Use an insect repellant.

• DEET is the most effective insect repellant and can be used safely in adults and children older than two months. Use products containing 20 percent to 30 percent DEET for adults and 10 percent DEET in children.

Fortunately, symptoms are uncommon. A full 80 percent of people actually infected have no symptoms at all. That’s an important number. It doesn’t look at people exposed to mosquito bites; it looks at people actually infected by the virus. Of those who develop symptoms, 97 percent will be mild. This mild illness is called West Nile fever and includes the symptoms of fever, headache, fatigue, and less commonly a rash on the trunk, swollen glands and eye pain. The rare more severe form of West Nile virus may include weakness, paralysis, and meningitis or encephalitis (a spinal cord or brain infection). Simply, then, if you feel well, don’t worry even if you might be infected. If you’re sick, but no worse than a cold or the flu, rest, drink fluids, use Tylenol or ibuprofen for symptoms and call your doctor if you have questions or concerns. Anything worse and, I don’t need to say, get checked! It is believed that you can get West Nile virus only once as immunity lasts a lifetime.

Next time, I’ll talk more about DEET and insect repellants.

For more information, the Colorado Department of Health has a wonderful resource at I’ll keep you posted as West Nile virus spreads and inevitably hits our beautiful state. Be smart, don’t worry, “fight the bite” and have a great summer!

Dr. Drew Werner is the vice chief of staff at Valley View Hospital in Glenwood Springs and the Eagle County Health Officer. He lives in Eagle with his family. E-mail comments about this column to

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