Prevention Best for Protection from West Nile Virus

By CnAgri2012-09-07 19:39:08 Print

While the summer's widespread and severe drought negatively affected agriculture production in many areas, it does not appear to have significantly affected the mosquito population, with this year on track to have the highest number of West Nile cases since the virus was first detected in the U.S. in 1999.

Mosquitoes act as the vector carrying the West Nile virus from avian reservoirs to other mammals, particularly humans and horses. More than 1,500 cases of West Nile have been reported to the Centers for Disease Control and Prevention, with 65 deaths. While the worst of the outbreak has been in Texas, Kansans have not escaped unscathed by the virus, with 19 reported cases and one death as of Aug. 28.

"The chances are real," said Ludek Zurek, entomologist with K-State Research and Extension. He said about 80 percent of people who contract West Nile exhibit no symptoms and simply develop long-lasting immunity as a result of exposure. Many of these cases are unreported. The other 20 percent experience flu-like symptoms and may not be diagnosed with the virus.

According to the CDC, only one in 150 positive cases will develop into the neuro-invasive form of the virus that can lead to paralysis and death. For Zurek, even that small chance is enough to warrant active preventive measures.

"When I see my daughters being bitten by mosquitoes, I don't like it -- no matter how low the chances are that you get it," he said. "As long as there is a chance, it's better to prevent being bitten by mosquitoes."

Since human vaccines against West Nile are still being developed, the best way to prevent contracting the virus is to avoid mosquito bites. Zurek recommended wearing long sleeves and pants, as well as a DEET-based insect repellant, especially at dawn and dusk or in areas where mosquito populations are high.

"Usually about 30 percent DEET concentration is plenty," Zurek said. "Higher concentrations don't offer better protection. Read the label to see how often to reapply."

People can also reduce the mosquito population by eliminating standing water around their home and property. Smaller containers of water, such as pet dishes or birdbaths, should be dumped once a week, Zurek said. Placing a few goldfish in water containers for livestock or horses prevents mosquitoes from breeding.

The end of the summer is typically the peak for human West Nile cases. Zurek urged people to be aware and take necessary precautionary measures. While West Nile usually affects people age 50 and older, or people with weakened immune systems, it has been known to affect people of all ages.

"Just because you are young does not mean you are 100 percent bullet proof from West Nile," he said. "It is true that older people are more susceptible to it. But people from any age category have died from it. So it's best to be on the safe side, be aware of the risk and lower it to minimum."