West Nile Virus

Most mosquito bites are just annoying, but a small percentage can carry a disease, such as West Nile virus (WNV). According to the Centers for Disease Control and Prevention (CDC), WNV can be transmitted to humans from the bites of mosquitoes that probably picked up the virus after feeding on infected birds. (Read about "Animal & Insect Borne Diseases") CDC reports there is no evidence to suggest that any other insect besides the mosquito transmits WNV. It is possible for pets to become infected, but pets cannot directly transmit the virus to you. Blood transfusions and organ transplants are other ways the virus can be spread. (Read about "Blood Donation Guidelines" "Transplants")

Once the virus is in the bloodstream, it multiplies and spreads. If it reaches the brain the results can be encephalitis, or in surrounding tissue, meningitis. (Read about "Encephalitis & Meningitis") CDC reports those at greatest risk of developing severe WNV infections are people older than 50.

WNV is now found in all states and has established itself as a seasonal epidemic in North America. It flares up in the summer and continues into the fall. Some years are worse than others.

Symptoms

According to CDC, most people (approximately 80 percent) infected with WNV have no symptoms or experience very mild symptoms. A mild case of WNV can last a few days and may include:

• fever
• headache (Read about "Headaches")
• body aches

CDC reports about one in every 150 people infected with WNV may develop severe symptoms including:

• severe headache
• high fever
• neck stiffness
• stupor or disorientation
• coma
• tremors
• convulsions
• muscle weakness and paralysis

The onset of symptoms is three to 14 days after being bitten by an infected mosquito. Severe WNV infections may last several weeks and neurological effects could be permanent.

Treatment

People who think they may have symptoms of WNV should see a doctor right away. Diagnosing the infection early may improve a person's chances of recovery. However, CDC lists no specific treatment for WNV and mild symptoms may pass on their own. In severe cases, hospitalization may be required and the outlook is more uncertain. CDC encourages pregnant women and nursing mothers to talk to their doctor if they develop symptoms that could be WNV. (Read about "Healthy Pregnancy")

Prevention

News of the epidemic nature of WNV in the U.S. probably has you on high alert. But don't let worries about mosquitoes keep you or your family from enjoying the outdoors. CDC suggests the best way to avoid WNV infection is to prevent mosquito bites and recommends these precautions:

• Try to stay indoors at dusk and dawn when mosquitoes are most active.
• Wear long sleeves and pants if outdoors during peak mosquito hours.
• Use mosquito repellents on skin or clothing. Follow manufacturer's instructions for applying the product.
• Get rid of mosquito breeding sites by emptying standing water found in flower pots, buckets, old tires, trash cans etc.
• Install or repair window and door screens.

If you find a dead bird, don't handle the body with your bare hands. Contact your local health department for instructions on reporting and disposing of the body.