August 26, 2009
CONTACT: Public Relations, Marketing and Media at 545-3020

           City Initiates Mosquito Eradication Measures
                          Citizens Urged to Take Precautions

The City of Columbia is stepping up mosquito eradication efforts as a result
of a confirmed human case of West Nile Virus in a city resident.

City forces have sprayed various large areas and will continue to spray as
recommended by DHEC or Richland County Vector Control.

City leaders are urging citizens to take necessary precautions to prevent
breeding grounds for mosquitoes. According to experts this is the most
effective way to approach this situation and help prevent the spread of West
Nile Virus. Citizens should also take steps for personal protection for
themselves and family members.

Visit the DHEC Web site at for more information about
West Nile Virus and the steps people can take to help minimize their risk.

Below are Mosquito Management tips that have been provided by DHEC:

Mosquito Management
Because some areas of the state do not have an organized mosquito management/control
program, the individual must take proper protective measures. Individuals can reduce
mosquito populations in many ways in and around their homes to protect themselves and
their family from mosquito bites. These activities can be grouped into three primary
management areas: personal protection, mosquito larval control, and adult mosquito
Personal Protection
The aim of personal protection is the prevention of mosquito bites. All individuals are
encouraged to use personal protective measures. Personal protection is particularly
important in areas of known or suspected occurrence of mosquito-borne diseases like

Window/Door Screens: Mosquitoes can be kept out of the home by keeping windows,
doors, and porches tightly screened (16-18 meshes to the inch). Frequently, mosquitoes
follow people into buildings or enter on humans or pets. For this reason, screen doors
should open outward and have automatic closing devices. Screens should be kept in good

Avoiding Mosquitoes: Most mosquito species bite at night, especially during twilight
hours, but some species bite during the day in wooded or other shaded areas. If possible,
avoid exposure during these times and in these areas. Children usually do not notice
mosquito bites while engaged in play. Be especially watchful and see that they are
protected. Avoid wearing perfume or scented products.

Protective Clothing: Wear light-colored clothing rather than dark when spending time
outdoors. Considerable protection from mosquito bites is offered by clothing made of
tightly woven materials that cover the arms and legs. Button the collars and keep trouser
legs tucked into socks or boots.

Vegetation Management: Homeowners can reduce the number of areas where adult
mosquitoes can find shelter by cutting down weeds and overgrown vines adjacent to the
house foundation and in their yards and mowing the lawn regularly.

Repellents: Repellents are an important tool to assist people in protecting themselves
from mosquito-borne diseases. A wide variety of insect repellent products are available.
CDC recommends the use of products containing active ingredients that have been
registered with the U.S. Environmental Protection Agency (EPA) for use as repellents
applied to skin and clothing. EPA registration of repellent active ingredients indicates the
materials have been reviewed and approved for efficacy and human safety when applied
according to the instructions on the label.

CDC evaluation of information contained in peer-reviewed scientific literature and data
available from EPA has identified several EPA-registered products that provide repellent
activity sufficient to help people avoid the bites of disease-carrying mosquitoes. Products
containing these active ingredients typically provide reasonably long-lasting protection:

      DEET (Chemical Name: N,N-diethyl-m-toluamide or N,N-diethly-3-methyl-
      Picaridin (KBR 3023, Chemical Name: 2-(2-hydroxyethyl)-1-
       piperidinecarboxylic acid 1-methylpropyl ester )
      Oil of Lemon Eucalyptus* or PMD (Chemical Name: para-Menthane-3,8-diol),
       the synthesized version of oil of lemon eucalyptus
      IR3535 (Chemical Name: 3-[N-Butyl-N-acetyl]-aminopropionic acid, ethyl ester)

* Note: This recommendation refers to EPA-registered repellent products containing the
active ingredient oil of lemon eucalyptus (or PMD). “Pure” oil of lemon eucalyptus (for
example, essential oil) has not received similar, validated testing for safety and efficacy,
is not registered with EPA as an insect repellent, and is not covered by this CDC

EPA characterizes the active ingredients DEET and Picaridin as “conventional
repellents” and Oil of Lemon Eucalyptus, PMD, and IR3535 as “biopesticide repellents”,
which are derived from natural materials. For more information on repellent active
ingredients, see EPA Active Ingredients in Insect Repellents.

Published data indicate that repellent efficacy and duration of protection vary
considerably among products and among mosquito species and are markedly affected by
ambient temperature, amount of perspiration, exposure to water, abrasive removal, and
other factors.

In general, higher concentrations of active ingredient provide longer duration of
protection, regardless of the active ingredient, although concentrations above ~50% do
not offer a marked increase in protection time. Products with <10% active ingredient may
offer only limited protection, often from 1-2 hours. Products that offer sustained release
or controlled release (micro-encapsulated) formulations, even with lower active
ingredient concentrations, may provide longer protection times. Regardless of what
product you use, if you start to get mosquito bites, reapply the repellent according to the
label instructions or remove yourself from the area with biting insects if possible.

These recommendations are for domestic use in the United States where EPA-registered
products are readily available. See CDC Travelers’ Health website for additional
recommendations concerning protection from insects when traveling outside the United

In addition, certain products that contain permethrin are recommended for use on
clothing, shoes, bed nets, and camping gear, and are registered with EPA for this use.
Permethrin is highly effective as an insecticide and as a repellent. Permethrin-treated
clothing repels and kills ticks, mosquitoes, and other arthropods and retains this effect
after repeated laundering. The permethrin insecticide should be reapplied to clothing
following the label instructions. Some commercial products are available pretreated with

EPA recommends the following precautions when using insect repellents:

      Apply repellents only to exposed skin and/or clothing (as directed on the product
      Do not use repellents under clothing.
      Never use repellents over cuts, wounds or irritated skin.
      Do not apply to eyes or mouth, and apply sparingly around ears.
      When using sprays, do not spray directly on face—spray on hands first and then
       apply to face.
      Do not allow children to handle the product. When using on children, apply to
       your own hands first and then put it on the child. You may not want to apply to
       children’s hands.
      Use just enough repellent to cover exposed skin and/or clothing. Heavy
       application and saturation are generally unnecessary for effectiveness. If biting
       insects do not respond to a thin film of repellent, then apply a bit more.
      After returning indoors, wash treated skin with soap and water or bathe. This is
       particularly important when repellents are used repeatedly in a day or on
       consecutive days.
      Also, wash treated clothing before wearing it again. (This precaution may vary
       with different repellents—check the product label.)
      If you or your child get a rash or other bad reaction from an insect repellent, stop
       using the repellent. Wash the repellent off with mild soap and water, and call a
       local poison control center for further guidance.
      If you go to a doctor because of the repellent, take the repellent with you to show
       the doctor.
      Note that the label for products containing oil of lemon eucalyptus specifies
       that they should not to be used on children under the age of three years.

Other than those listed above, EPA does not recommend any additional precautions for
using registered repellents on pregnant or lactating women, or on children. For additional
information regarding the use of repellent on children, please see the CDC’s Frequently
Asked Questions about Repellent Use.

DEET-based repellents applied according to label instructions may be used along with a
separate sunscreen. No data are available at this time regarding the use of other active
repellent ingredients in combination with a sunscreen. For additional information on
using repellents, see EPA-registered repellents.

DEET (N, N-diethyl-m-toluamide):

      DEET remains the most effective insect repellent currently available.
      DEET has been used safely for over 40 years by millions of people worldwide.
      DEET always should be used in accordance with the manufacturer's product label.
      Formulations containing 30 percent DEET provide long lasting protection and are
       recommended for use in adults and children over 2 months of age. Higher
       concentrations do not provide significantly increased or longer repellent effect.
       Lower concentrations of DEET provide a shorter duration of protection and have
       not been shown to be safer for adults or for children.

The following precautions should always be followed when using DEET:
      Always follow the instructions on the product label.
      Do not apply DEET to children under 2 months of age.
      DEET should not be applied to hands or near eyes and mouth of young children.
      Young children should not be allowed to apply DEET to themselves.
      DEET should not be applied over cuts, wounds, or irritated skin.
      Spray clothing with repellents containing Permethrin or DEET because
       mosquitoes might bite through thin clothing.
      Avoid spraying DEET in enclosed areas or around food.
      Treated skin should be washed with soap and water after returning indoors.

For further information about DEET and recommendations for its use on adults
and children:

      American Academy of Pediatrics (AAP)
      U.S. Centers for Disease Control and Prevention specifics for DEET
      U.S. Environmental Protection Agency
      New England Journal of Medicine (July 4, 2002)

Larval Mosquito Control
By eliminating or treating mosquito-breeding areas, individuals can impact the number of
mosquitoes in and around their homes. Some mosquitoes have limited flight ranges and
might fly only a few hundred feet from their breeding areas. One such mosquito, Culex
quinquefasciatus, a vector of West Nile virus, breeds extensively in water containers
around houses and commonly is known as the Southern House Mosquito. Every effort
should be taken to eliminate standing water that may support mosquito breeding. Some
suggested activities are as follows:

      Eliminate all items from your yard like tin cans, jars, bottles, old tires, drums, old
       appliances, or any item that will catch and hold water.
      Repair any leaky pipes or outside faucets.
      Change the water in birdbaths at least once each week.
      Root or grow outdoor plants in sand or soil instead of only water.
      Empty and clean children’s wading pools at least once each week and maintain
       swimming pools with proper pool chemicals.
      Empty and refill pet-watering containers daily.
      Cover trash containers/garbage cans to prevent accumulation of rainwater.
      Keep gutters clean and free of leaves and other debris, and check frequently.
      Fill in tree holes and hollow stumps with sand or concrete.
      Stock ornamental garden ponds with mosquito-eating minnows, and keep
       vegetation, which protects mosquito larvae, trimmed from the edge of the pond.
      Store boats/canoes covered or upside down so they will not collect and hold
       rainwater. Make sure that tarps or other covers do not hold water.
      Drain or fill any low places in your yard where water collects and stands for more
       than five to seven days.
      Ensure that roadside ditches or other drainage ditches are kept free of vegetation
       or other debris that would cause them to hold water and prevent proper drainage.
       Particular attention should be given to driveway culverts. See that water does not
       stand inside or near the ends of the culvert.
      Be sure that all permanent water containers such as wells, septic tanks, cisterns,
       water tanks, and cesspools are tightly covered and insect-proof.
      Inspect septic drain fields. Do not allow septic water to accumulate on the ground
      Screen rain barrels so adult females can not lay eggs there.
      Use mosquito control products from your local lawn and garden/home
       improvement store to treat small areas that can not be drained.

Adult Mosquito Control
Although elimination of larval breeding areas and larval control efforts will decrease a
great number of mosquitoes, some species have flight ranges from one to several miles
and might present a biting problem in and around your home. Because a continuous re-
infestation of adult mosquitoes from breeding areas might occur, adult control activities
are usually temporary.

Most adult mosquitoes require and seek cool, dark, damp areas to rest during the day. By
eliminating the availability of such areas on your property, adult mosquitoes can not find
suitable places to rest and will seek resting places elsewhere. Eliminating mosquito-
resting areas might help in reducing the number of biting mosquitoes on your property
and can be accomplished in the following ways:

      Use screens on windows and doors.
      Keep your car windows rolled up and garage doors closed at night.
      Use yellow light bulbs or sodium vapor orange lights for outside lighting
      Wear long-sleeved shirts and long trousers while outside.
      Keep your shrubs, ivy, and grass trimmed.

Under certain circumstances, such as planned outdoor parties or similar activities,
temporary relief outdoors can be had by using a small hand-held fogger (not a garden
sprayer) made specifically for mosquito control. A special insecticide will be sold for use
with the fogger. Use it a few hours before an outdoor activity is planned. It will not be
very effective on a windy day. Fogging applications are temporary and usually kill only
those mosquitoes that are flying in the area at the time. Therefore, applications are most
effective when applied at the time mosquitoes are most active, during twilight.
Applications made earlier may kill some resting mosquitoes in the area. If the sprayed
space is relatively small, mosquitoes entering from outside of the area still might cause a
significant biting problem. Heat-activated repellent pads or mosquito coils may be
somewhat effective in repelling mosquitoes in a small area such as a patio. Check with
your local lawn and garden/home improvement store for mosquito control products to use
around the home. Read and follow all label directions. Do-it-yourself mosquito spraying
is not a substitute for a community-based mosquito control program or for personal

Barnard DR, Xue RD. Laboratory evaluation of mosquito repellents against Aedes
albopictus, Culex nigripalpus, and Ochlerotatus triseriatus (Diptera: Culicidae). J Med
Entomol. 2004;41(4):726-30.

Barnard DR, et al. Repellency of IR3535, KBR3023, para-menthane-3,8-diol, and DEET
to Black Salt March mosquitoes (Diptera: Culicidae) in the Everglades National Park. J
Med Entomol. 2002; 39(6): 895-899.

Fradin MS, Day JF. Comparative efficacy of insect repellents against mosquito bites. N
Engl J Med. 2002; 347(1):13-8.

Thavara U et al. Laboratory and field evaluations of the insect repellents 3535 (ethyl
butyletylaminopropionate) and DEET against mosquito vectors in Thailiand. J of Am
Mosq Cont Assoc. 2001, 17(3):190-195.

Additional information regarding West Nile Virus and Mosquito
Management can be found at:

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