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Central Region Groundwater Website
Click here to check the current National Threat Advisory Level
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VECTOR:
Defined as "disease-carrying insect"
West Nile Virus
Brown Recluse Spiders
2007 Dead Bird Collection Criteria
2007 Bird & Mosquito Pool Testing
Sites/Results
Standing Water Report Form
Mosquito Awareness Checklist
History of West Nile Virus
The West Nile Virus (WNV) was first found in a febrile adult woman in the West
Nile District of Uganda in 1937. The virus became recognized as a cause of
severe human meningoencephalitis (inflammation of the spinal cord and brain) in
elderly patients during an outbreak in Israel in 1957.
WNV first emerged in the United States in the New York metropolitan area in the
fall of 1999. From there it quickly spread across the country.
WNV was first identified in Illinois in the summer of 2001 after laboratory
testing confirmed that two dead crows found in Cook County had died of it.
Illinois’ first human case was reported in 2002. By the end of 2002, 884 human
cases had been reported, 67 of which resulted in death, and WNV would be present
in 100 of Illinois’ 102 counties. That year Illinois reported more cases of the
disease and more deaths than any other state. In 2003, the epicenter of disease
would begin to move westward and incidence rates in Illinois would briefly drop
as only 54 cases of the disease and 1 death were reported that year. There would
be 60 cases and 4 deaths the following year. In 2005, Illinois would post the
second highest rates of incidence in the nation with 252 cases and 12 deaths.
Illinois reported 215 cases and 10 deaths in 2006, the sixth highest number of
cases in the United States.
WNV was first detected in Tazewell County in July 2002. That year 23 horses, 9
batches of mosquitoes, 6 birds, and 1 human tested positive for WNV.
Culex information
Culex Pipiens is the Northern house mosquito,
which transmits the West Nile Virus. These mosquitoes develop in areas such as:
overgrown ponds, stagnant and shaded pools, poorly managed waste-effluent
lagoons, catch basins, puddles in drainage ditches, and mostly artificial
containers. Some artificial containers include: old tires, tin cans, bird baths,
and roof gutters. These mosquitoes lay eggs on the surface of the water in
groups. The larvae become full grown in 7-10 days and the pupae transform into
adults in 3-4 days.
Transmission
The female Culex 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 the virus to humans and
animals while feeding on 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.
Signs/Symptoms
The majority of cases result in a symptom free infection. A smaller percentage
of cases of WNV result in a mild febrile illness (West Nile Fever) characterized
by fever, headache, body aches, nausea, skin rash, and swollen lymph nodes.
Rarer, more severe cases of WNV cause encephalitis (swelling of the brain)
and/or meningitis (swelling of the tissues lining the brain). These more severe
forms often have similar early symptoms as West Nile Fever, but are
characterized by high fever, headache, neck stiffness, stupor, disorientation,
coma, tremors, vision loss, numbness, and paralysis.
Risk Groups
Everyone is at risk for contracting West Nile Virus. Elderly people and those
with compromised immune systems are more susceptible than younger age groups.
There is no vaccine to prevent the contraction of the West Nile Virus.
|
2006 Human
Cases by Age Group |
|
Age |
Cases |
% Per Age |
|
0-14 |
4 |
2% |
|
15-29 |
11 |
5% |
|
30-44 |
48 |
22% |
|
45-59 |
71 |
33% |
|
60-74 |
45 |
21% |
|
75+ |
36 |
17% |
|
Unknown |
0 |
0% |
|
TOTAL |
215 |
|
Yard Protection
Any place where water lasts more than seven to ten days can be a possible
breeding area for mosquitoes. Residents need to check their property and
eliminate any potential areas were mosquitoes might breed. These mosquitoes
develop in areas such as: overgrown ponds, stagnant and shaded pools, poorly
managed waste-effluent lagoons, catch basins, puddles in drainage ditches, and
mostly artificial containers. Some artificial containers include: old tires, tin
cans, bird baths, and roof gutters.
Personal Protection
Residents are encouraged to stay indoors at dawn, and dusk through early
evening, when mosquitoes are most active.
When outdoors between dusk and dawn, wear loose-fitting, light-colored, and
long-sleeved tops and long pants made of tightly woven materials to keep
mosquitoes away from the skin.
Mosquito Repellents
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Use a repellent containing DEET, Picaridin, or Oil of Lemon Eucalyptus.
Apply sparingly to exposed skin and/or clothing as indicated on the
product's label.
-
According to the CDC, “No definitive studies exist in the scientific
literature about what concentration of DEET is safe for children. No serious
illness has been linked to the use of DEET in children when used according
to manufacturer’s recommendations.”
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According to the American Academy of Pediatrics, “Insect repellents
containing DEET (N,N-diethyl-m-toluamide, also known as
N,N-diethyl-3-methylbenzamide) with a concentration of 10% appear to be as
safe as products with a concentration of 30% when used according to the
directions on the product labels. DEET is not recommended for use on
children under 2 months of age.”
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If you are concerned about using repellent products on children you may wish
to consult a health care provider for advice or contact the National
Pesticide Information Center (NPIC) through their toll-free number,
1-800-858-7378 or
npic.orst.edu
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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.
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Do not apply repellent to children's hands. (Children tend to put their
hands in their mouths.)
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Do not allow your children to apply insect repellent to themselves; have an
adult do it for them.
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Keep repellents out of reach of children.
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Do not apply repellent to skin under clothing. If repellent is applied to
clothing, wash treated clothing before wearing again.
The Role of the Tazewell County Health Department
The Tazewell County Health Department collects mosquito samples using Gravid
Traps (traps designed to attract and collect egg bearing female mosquitoes) and
tests them for West Nile Virus using a technique known as a rapid
immunochromatographic assay. This technique involves grinding the mosquitoes in
a testing solution and then using a test strip to determine the presence or
absence of West Nile Virus. These results are then reported to the Illinois
Department of Public Health.
In addition to collecting and testing mosquitoes, we also collect dead birds for
testing. These birds are then sent off to a state lab for testing. Bird
collection begins in May. Please call us when you find a dead bird meeting the
following criteria:
• The bird is dead, but shows no signs of decomposition.
• The bird shows no sign of why it died, other than disease.
• The bird must be one of the following: Crow, Blue Jay, Grackle, Starling,
Robin, Cardinal, Sparrow, Finch, Hawk, or Owl.
To learn more about West Nile Virus in Illinois go to the Illinois Department of
Public Health’s West Nile Virus page by clicking
here. More information can also
be found by visiting the Centers for Disease Control’s page on West Nile Virus
by clicking here.
Brown Recluse Spiders
Brown recluse spiders have bodies generally 1/4" to 3/4"
long. Their body is relatively flat, and the head has a violin like mark. They
thrive in woods, brushy areas, particularly in leaf litter and low vegetation,
indoors in closets, under rugs, and blankets.
The below section was extracted from an article in the
Pantagraph, Bloomington, Illinois, newspaper, written by Scott Richardson, June
2002.
"Unlike most spiders, the brown recluse has fangs long
enough to pierce human skin. Its long-acting venom causes deterioration of
surrounding tissue. An ulcer forms that may take months and plastic surgery to
heal. A bite on a toe or finger can cause its loss.
The good news is the brown recluse is aptly named. The
spiders prefer to avoid humans. They are non-aggressive and tend to congregate
in hiding places where they can lie in wait for insects to eat.
The spiders may survive Illinois winters outdoors in the
southern third of the state. But they move indoors, usually in larger buildings
or in the basements of homes or sheds in the northern two-thirds of the state.
People are generally bitten when picking up wood from a
pile, moving boxes without looking underneath, or putting on clothes or a
blanket that had been stored for a while. Caution dictates wearing gloves,
looking before you grab and shaking out clothes before wearing them.
The best way to learn if an area harbors brown recluse
spiders is to place sticky traps. If found and definitely identified, more
investigation is needed to find exactly where they are living so pesticide can
be applied 'judiciously'."
Interviewed for this article was Dr. Linn Haramis,
Illinois Department of Public Health entomologist, and Doug Whitman, Illinois
State University entomologist.
Of the 25 spiders submitted to Tazewell County Health
Department for identification of Brown Recluse Spider, 24 have been submitted to
Illinois Department of Public Health for further testing. Of those 24, 22 have
not been identified as the Brown Recluse Spider. We are currently awaiting
results for the others. One residence has been positively identified as having
Brown Recluse Spiders.
HOW TO AVOID BROWN RECLUSE SPIDER BITES:
1. Caulk around doors and windows.
2. Recycle cardboard boxes, which attract the spiders.
3. Wear gloves when working in basements, attics, and garages.
4. Carefully shake out blankets, bedding, and towels that are seldom used.
5. Avoid storing lumber in basements, garages, and outbuildings.
6. Handle fireplace cordwood with gloves. Tamp and roll logs before bringing
them indoors.
7. With gloves on, shake out clothing and boots stored in basements, attics,
garages or outbuildings.
8. Examine used and antique furniture carefully before bringing it into the
home.
9. Wear protective clothing when entering a crawl space.
IF YOU'VE BEEN BITTEN:
SEEK EMERGENCY MEDICAL ATTENTION IMMEDIATELY! Any delay may
increase the risk of tissue damage. If possible, safely try to capture the
spider for later identification and verification.
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