- Transmission Process
- Signs & Symptoms
- Risk Groups
- Yard Protection
- Personal Protection
- Mosquito Repellents
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.
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:
- Body aches
- Skin rash
- ?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
- Neck stiffness
- Vision loss
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 Groups||Cases||Percent Per Age Group|
15 to 29
30 to 44
45 to 59
60 to 74
75 and over
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:
- Artificial containers including:
- Bird baths
- Old tires
- Roof gutters
- Tin cans
- Catch basins
- Overgrown ponds
- Poorly managed waste-effluent lagoons
- Puddles in drainage ditches
Stagnant and shaded pools
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
- 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.”
- 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.”
- 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, 800-858-7378.
- 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 mouths.)
- Do not allow your children to apply insect repellent to themselves; have an adult do it for them.
- Keep repellents out of reach of children.
- Do not apply repellent to skin under clothing. If repellent is applied to clothing, wash treated clothing before wearing again.