Environmental Health

Mosquito-borne Diseases in Fayette County

West Nile Virus (WNV) was first reported in Fayette County from a bird in 2002. In fact, 11 WNV+ birds were reported in the county that year. Bird testing was essentially discontinued in 2013, with the focus changed to mosquito surveillance and educating the public. The Georgia Department of Agriculture monitors mosquito-borne diseases in horses, companion animals, and livestock, and both Eastern Equine Encephalitis (EEE) and WNV are occasionally reported in Fayette County. There are vaccines for both these viruses in horses.

Some level of mosquito surveillance has been done in Fayette County since 2004, and although no mosquitoes have tested positive for WNV, the virus is considered to be endemic in Georgia. This means that there is a risk of getting infected with WNV during mosquito season.

What we must realize is that mosquito-borne viruses (arboviruses like West Nile) have been active in Georgia for many years. EEE and LaCrosse encephalitis (LAC) were the most common arboviruses here before WNV was introduced. Human infections with these mosquito-borne viruses are very rare and the risk of infection can be reduced by taking simple measures to avoid mosquito bites. WNV is a disease of birds that is spread by mosquitoes. The only way for humans to get an arbovirus like WNV is from the bite of an infected mosquito. Not every mosquito will be infected. Moreover, of the few (humans) who do get the virus: less than 1% will have severe symptoms.

It follows that reducing the number of mosquitoes that we are exposed to decreases the likelihood of being bitten. Let us review some preventive measures.

Try not to be outdoors in areas where mosquitoes are known to be, particularly at dawn, dusk, and early evening. These are prime feeding times for mosquitoes.
Wear weather-appropriate long-sleeved shirts and long pants when outside for extended periods in the areas where mosquitoes are likely to be.
Spray clothing with permethrin and/or apply an EPA-registered mosquito repellent (https://dph.georgia.gov/mosquito-borne-diseases) to exposed skin. Always read instructions carefully before using any insect repellant, especially on infants, small children, or persons with allergies. For children use products that contain 10% or less DEET. For adults use products that contain no more than 30% DEET. Check with your primary care physicians before using repellents on pregnant women or infants. Be sure to wash off treated skin when mosquito exposure has ended.

Mosquitoes that carry WNV don't fly very far away from their breeding place and need only a little water in order to lay hundreds of eggs. Additionally, one of our biggest pest species, the Asian tiger mosquito, also lays its eggs in any container that can hold water, and its eggs can sit without water for years, hatching when the containers fill up again. You know that empty flowerpot that you've had sitting out back for a while? If it can hold water: it easily becomes a mosquito breeding place. Almost anything that will hold water for 7-10 days can produce these pests! One of our best defenses is not to give mosquitoes a chance: eliminate all standing water from your property.

Properly throw away or destroy old tires.
Dispose of tin cans, jars, plant pots, and any other container that can hold water - or store them in a dry place.
Make sure roof gutters drain properly. Clean clogged gutters in the spring and fall.
Store wheelbarrows, tubs, buckets, barrels, and boats upside down, so that water cannot accumulate in them. (Cleaning an article that has been emptied of standing water with a solution of bleach and water will get rid of those eggs that have adhered to the sides of the container.)
Screen or cover rain barrels.
Change the water in birdbaths, small wading pools, and pet dishes at least once a week. Aerate ornamental ponds or stock them with fish.
Properly chlorinate backyard swimming pools. Cover any pool that is not in use, so rainwater and leaves do not accumulate in it. Be sure the cover does not hold pockets of water.

You may ask the question: "If controlling mosquitoes is so important, why isn't our community being sprayed? A good Integrated Mosquito Management (IMM) program requires trained personnel and sustainable funding to work well (http://www.gamosquito.org/resources/papers/BMP_IMM.pdf and http://www.gamosquito.org/resources/papers/AMCA_BMP.pdf). Without all the components of an IMM program, mosquito control is likely to fail.