Print Page


ASK A SPECIALIST

Mosquitoes spread the West Nile Virus.

By DIANE ALSTON
USU Extension entomologist

How can I guard against West Nile Virus?

West Nile Virus was first detected in North America in 1999 and in Utah in 2003. West Nile Virus is transmitted by female mosquitoes while taking a blood meal that is required to develop eggs. Horses, humans and some birds (particularly crows, ravens and jays) are susceptible to West Nile Virus. So far in 2012, one human case has been confirmed in Utah.

Approximately 80 percent of humans infected with West Nile Virus never show symptoms. Most people's immune systems are healthy enough to overcome the virus. Up to 20 percent of those bitten will develop West Nile Fever and display symptoms similar to the flu.

Symptoms typically last a few days and should be treated by drinking fluids and resting. About one in 150 people infected will become seriously ill and require hospitalization.

People over 50 years of age and those with compromised immune systems are at higher risk to develop more serious complications from West Nile Virus.

Consider these tips for protection.

* Wear clothing that reduces exposure to mosquito bites, such as long-sleeved shirts, long pants, socks and shoes.

* Stay indoors during peak flight activity. Mosquitoes that transmit West Nile Virus most actively feed from dusk through dawn.

* Protect yourself with repellent. DEET is an effective mosquito repellent available in several concentrations. Products containing DEET have a relatively low risk to humans and the environment.

DEET can be applied to the skin, but should not be applied directly to the face. Children should use DEET sparingly because of eye and mucous irritations.

Picaridin is an alternative for people with sensitivities to DEET-based products. It is effective, almost odorless and can be applied directly to the skin.

Another repellent, BioUD is sold commercially as Bite Blocker® and is derived from a wild tomato plant. Bite Blocker can be applied to the skin and has no child restrictions. Unlike DEET, BioUD will not melt plastic and is not flammable. Permethrin is another highly effective repellent, and products containing permethrin can be applied to clothing, shoes and camping gear.

Oil of eucalyptus is a plant-based repellent and is similar in effectiveness to low concentrations of DEET.

* Eliminate standing water. Because mosquito eggs are deposited in standing water, anything you do to reduce breeding sites will decrease the number of adult mosquitoes. This includes modifying landscaping to minimize pooling water in ditches and other low spots in the yard.

* Keep containers clean and dry. Empty and clean watering cans, flower pots or other potential sources of standing water when they are not in use. Drill holes to allow drainage. Garbage cans and recycling bins can hold rain water for days.

* Maintain and frequently cycle or change water in pools, fish or ornamental ponds, bird baths and pet bowls. Ornamental ponds with flowing water, such as from waterfalls, are not conducive to mosquito breeding. Mosquitoes breed in standing water.

* Properly chlorinate swimming pools and hot tubs to discourage female mosquitoes from laying eggs.

* Prevent mosquitoes from entering the home. Keep windows and doors closed, repair torn screens, insulate window fans or air conditioners and close fireplaces when not in use.

Direct column topics to: Julene Reese, Utah State University Extension writer, Logan, Utah 84322-4900; 435-797-0810; julene.reese@usu.edu




Print Page