WHAT SHOULD WE DO ABOUT THE WEST NILE VIRUS?

by Whit Gibbons

August 26, 2002

West Nile Virus (WNV) is having its fifteen minutes of fame. It is among the least of our environmental problems, but because of inflated media attention it is a hot topic. Last year, before September 11, the media hyped shark attacks. If you followed those reports, shark attacks seemed rampant. In the true spirit of a self-fulfilling prophecy, the more attention the topic received, the more pressing it became, and the more the public wanted to hear about it.

I am in no way belittling the distress of victims and their families who have suffered from WNV. Or as Mark Bailey of Conservation Services Southeast put it recently, "None of this is intended to minimize the gravity of the West Nile Virus, but misinformation and/or overreaction often go hand-in-hand with 'new' diseases." By mid-August, fewer than a dozen people in the United States had died from the disease. We should begin to question how much media attention WNV really deserves. A mob mentality can often develop over unrestrained media hype, which can lead to long-term problems that are far more serious than the event being reported. I have actually heard of suggestions that we eliminate small wetlands to control mosquitoes and stop the rampage of this newly introduced virus. Pure foolishness. People are acting as if we just discovered that mosquitoes are among us and they bite.

Let's consider some facts about WNV. First, human infection is only possible from the bite of an infected mosquito, usually more than one. The proportion of mosquitoes that are infected is minuscule, and not all bites from infected mosquitoes will result in transmission of the virus. Furthermore, the Centers for Disease Control (CDC) states that "less than 1% of persons infected with WNV will develop severe illness." Most people who get the virus have flu-like symptoms, and many people who have had WNV did not even know it. Also, once you have WNV and recover, you are presumably immune for life, according to the CDC. I am not saying that contracting the virus cannot be serious, but the threat is being overstated.

More than 100 species of birds infected with WNV have been documented. Most birds survive, but for some reason crows and blue jays often become ill and some die. WNV infection has also been reported in horses, cats, bats, chipmunks, skunks, squirrels, domestic rabbits, and possibly dogs. However, the only means of transmitting the virus to any individual person or animal is believed to be from the mosquito.

The common Culex mosquito is the most often cited culprit for the disease in the United States. But knowing what kind of mosquito we should be wary of really does not matter to any of us when it comes to a one-on-one encounter with a mosquito. If I see it after it lands, no matter what kind it is, I will try to kill it.

Some straightforward recommendations can be made about how to avoid or control mosquito problems. Most people already know that mosquitoes are more likely to be in dark places than in direct sun, so dawn, dusk, and early evening are peak mosquito-biting times. Keeping window screens repaired and doors closed is a rather obvious step to take. The CDC recommends that "to avoid helping mosquitoes breed . . . routinely empty water from flower pots, pet bowls, clogged rain gutters, swimming pool covers, discarded tires, buckets, barrels, cans, and other items that collect water in which mosquitoes can lay eggs."

The CDC notes that mosquito repellents that contain "a higher concentration of active ingredient (such as DEET) provide longer-lasting protection." But they also state that "Vitamin B and ultrasonic devices are NOT effective in preventing mosquito bites." In other words, turn off the bug zappers that kill lots of fascinating, harmless insects and few mosquitoes.

West Nile Virus is likely to be a short-term problem because most infected animals will build up immunities. We certainly should not begin any wetlands eradication programs, which would be an overreaction tantamount to last year's recommendations by some that we should start killing sharks along American beaches. Perhaps the media ought to find some other environmental topic to hype. Something of consequence--like global warming or national water problems.



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