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Advice for those living in high-risk areas for the West Nile virus

Advice for those living in high-risk areas for the West Nile virus

Over 1,500 cases of West Nile Virus (WNV) have been reported to date this year, the highest number year on record since the virus was first identified in 1999. A majority of cases involve just six states (Texas, South Dakota, Mississippi, Oklahoma, Louisiana, and Michigan) with Texas being the hardest hit with 45% of all reported cases. Nationwide, there have been 66 deaths so far.

With almost 200 mosquito species occurring in the US, at least 43 of these species can transmit WNV. The transmission cycle is cyclical between birds and mosquitoes. The cycle usually starts with an infected bird or animal. Certain types of birds such as crows are particularly susceptible to WNV and over 138 species of birds are susceptible to WNV. In this cycle, a female mosquito takes a blood-meal from an infected animal and becomes infected itself. Female mosquitoes only require a blood-meal for egg production. Otherwise, both male and female mosquitoes subsist on a diet of nectar. When an infected female mosquito takes its next blood-meal, it can transmit the virus to an “incidental” host such as humans and horses.

Given the large number of species (birds and mosquitoes) involved in the WNV cycle, it’s important for us “incidental” hosts to be aware of how to protect ourselves.


Do remove all standing water from around your home

Stagnant water is an ideal place for mosquitoes to lay eggs and a great living space for mosquito larvae. In just a couple of weeks, mosquito eggs can mature into flying mosquitoes. Stagnant water can be found in bird baths, flower pots, tire swings, and even pet water dishes. Be sure to drain these regularly. For bird baths and pet water dishes, drain and replace the water every few days.

Do try to avoid being outside from dusk until dawn

This is the most active time period for many mosquitoes. Therefore, there is a greater chance of being bitten during these times. Activities such as pool parties and yard maintenance should be concluded before dusk. However, if you must be outside, see Do #3.

Do use EPA approved mosquito repellents

Wear light-weight long sleeve shirts and long pants to protect the skin from mosquitoes. If you have exposed skin, you want to make sure you use EPA approved mosquito repellent. Many products claim to repel mosquitoes, but be sure you use one that is approved by the EPA and, therefore, proven to be effective. You can get more information about EPA approved repellents at

Do ensure all window and door screens are in good repair

A summer breeze is great, but not when it brings mosquitoes inside. Be sure all screens are tightly in place with no holes. Mosquitoes can track carbon dioxide emissions from humans (exhaled breath) up to 54 feet away. If mosquitoes have access inside your home, they will find you.

Do contact your local vector control agency

Vector control surveillance plays an important role in determining appropriate locations for aerial pesticide spraying and elimination of standing water at foreclosed/abandon properties. If you notice an increase in mosquito around your home, be sure to contact your local vector control agency so that they can spray when needed.


Do not use repellents on children younger than 2 months

Protect infants with netting around seats and carriers. Always follow the explicit directions for application on mosquito repellent containers. Some repellents may not be used on children younger than 3 years old.

Do not use products containing both sunscreen and repellent

It’s recommended that you apply sunscreen first and then a mosquito repellent. Reapplication rates are different for each component. According to the new FDA rules released last summer, sunscreen should be applied at least every two hours. Mosquito repellents typically last longer than two hours but re-application rates vary depending on the concentration percentage of the active ingredient and your outdoor activity.

Do not apply mosquito repellent under your clothing

Mosquito repellent should only be used on exposed skin. Mosquito repellents should never be apply to cuts, wounds, or irritated skin. If redness or irritation occurs, discontinue use and seek guidance from your local poison control agency.

Do not forget that being over 50 years old increases your chances

People over 50 are more likely to have weakened immune systems due to other health issues. Anyone who is immunocompromised carries an increased risk of developing serious symptoms of WNV if infected. Be vigilant in your mosquito repellent regimen and report symptoms to your health care provider.

Do not handle a dead bird with your bare hands

Contact your local animal control or health department for advice on reporting and appropriately disposing of the carcass. If officials say it is okay for you to dispose of the carcass, you need to wear gloves to handle it. If decomposition has begun, clean the area with a 10% bleach solution after disposing of the carcass. Once disposal and clean-up is complete, thoroughly wash hands with hot, soapy water.

Jumping cartoon

Remember that you don’t have to sequester yourself indoors for the rest of the season in fear of WNV. By following these simple tips, you can still enjoy your favorite outdoor activities and greatly reduce your chances of contracting WNV.

More expert advice about West Nile

Photo Credits: Mosquitos: The Basics by Flickr: fairfaxcounty; Check Man, Cross Man and Jump Man © ioannis kounadeas -

Michelle Brown, PhDResearch scientist

Dr. Brown is currently developing safe, non-insecticidal mosquito repellents by targeting the mosquitoes’ primary host-seeking mechanism, carbon dioxide detection, at Olfactor Laboratories in Riverside, CA. ...

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