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Protection Against Mosquitoes
Avoid places and times
when mosquitoes bite. Generally, peak biting periods for the type of mosquitoes
capable of transmitting WNV occur just before and after sunset and just before
dawn.
Apply insect repellent
containing 25-35% DEET when you're outdoors.
Assure door and window,
patio and porch screens are tight-fitting and in good repair.
Wear long-sleeved tops,
long pants, socks and shoes and clothing made of tightly woven materials to keep
mosquitoes away from skin. Light colored clothing is best.
Eliminate stagnant water
in bird baths, ponds, flower pots/trays/saucers, water fountains and water features
and get rid of tires, buckets or other receptacles that could serve to contain
water where mosquitoes might breed.
Be sure to check clogged
gutters and flat roofs that may have poor drainage.
Make sure cisterns, cesspools,
septic tanks, rain barrels and trash containers are covered tightly with a lid
or with 16-mesh screen.
Level the ground around
residence so water can run off and not collect in low spots. Fill in holes or
depressions near the building that accumulate water.
Fill in tree rot holes
and hollow stumps that hold water.
Stock ornamental water
gardens with fish (e.g. minnows, "mosquito fish" or goldfish) that eat
mosquito larvae.
Treat small pools of water
with "Bti", a bacterial insecticide. Many hardware stores carry doughnut-shaped
Bti briquettes (Mosquito Dunks) for this purpose. Be sure to follow the insecticide
label exactly.
Keep weeds and grass cut
short; adult mosquitoes look for these shady places to rest during the hot daylight
hours.
Bird and wild game hunters
should follow the usual precautions when handling wild animals and birds. They
should wear gloves when handling and cleaning birds or animals to prevent blood
exposure to bare hands.
West Nile Virus - Transmission,
Signs & Symptoms
People become infected by
the bite of a mosquito infected with West Nile Virus. Mosquitoes become infected
when they feed on infected birds, which may circulate the virus in their blood
for a few days. Infected mosquitoes can then transmit WNV to humans and animals
while biting to take blood. The virus is located in the mosquito's salivary glands.
During blood feeding, the virus may be injected into the animal or human where
it may multiply possibly causing illness. West Nile encephalitis is NOT transmitted
from person-to-person. There is no evidence that a person can get the virus from
handling live or dead infected birds. However, persons should avoid bare-handed
contact when handling any dead animals and use gloves or double plastic bags to
place the carcass in a garbage can.
Most people infected with
West Nile virus have no clinical symptoms of illness, but may become ill 3-15
days after the bite of an infected mosquito. Infections can be mild and include
fever, headache, body aches, and occasionally with skin rash and swollen lymph
glands. Sever symptoms are marked by headache, high fever, neck stiffness, stupor,
convulsions, muscle weakness, paralysis and, rarely, death. It is assumed that
if a person contracts West Nile virus they develop a lifelong natural immunity
to future infection, but it may weaken in later years. While everyone is at risk
of West Nile disease, those at highest risk are persons 50 years of age or older.
Using Insect Repellants
Safely
Insect repellents help people
reduce their exposure to mosquito bites that may carry potentially serious viruses
such as West Nile virus, and allow them to continue to play and work outdoors.
Many of the mosquitoes that carry the West Nile virus are likely to bite around
dusk and dawn. Female mosquitoes bite people and animals because they need the
protein found in blood to help develop their eggs. Mosquitoes are attracted to
people by skin odors and carbon dioxide from breath. Repellents contain a chemical,
which does not kill, but repels the mosquito and are effective only at short distances
from the treated surface, so you may see mosquitoes flying nearby. When using
repellents be sure to follow the directions on the product to determine how frequently
you need to reapply repellent. Sweating, perspiration or getting wet may mean
that you need to re-apply repellent more frequently. Repellents containing a higher
concentration of active ingredient, such as DEET, provide longer-lasting protection.
If you are no longer getting bites, there is no reason to apply more repellent.
A product containing 23.8% DEET can provide an average of 5 hours of protection
from mosquito bites.
Guidelines for Repellant
Use
Use enough repellent to
cover exposed skin or clothing. Don't apply repellent to skin that is under clothing.
Heavy application is not necessary to achieve protection
Do not apply repellent
to cuts, wounds, or irritated skin
After returning indoors,
wash treated skin with soap and water
Do not spray aerosol or
pump products in enclosed areas.
Do not apply aerosol or
pump products directly to your face. Spray your hands and then rub them carefully
over the face, avoiding eyes and mouth
It is recommended that
for children under 2 years of age only one application per day of repellent containing
DEET should be used.
When using repellent on
a child, apply it to your own hands and then rub them on your child. Avoid children's
eyes and mouth and use it sparingly around their ears
Do not apply repellent
to children's hands. (Children tend to put their hands in their mouth
Do not allow young children
to apply insect repellent to themselves; have an adult do it for them. Keep repellents
out of reach of children
If repellent is applied
to clothing, wash treated clothing before wearing again.
There are no reported adverse
reactions following use of repellents containing DEET in pregnant or breastfeeding
women. In rare cases, these products may cause skin reactions.
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