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West Nile Virus
West Nile Virus
Symptoms
Prevention
Personal Protection
Detecting West Nile in Baker County
Resources

What it is

West Nile Virus is caused by a virus carried by infected mosquitoes. Mosquitoes become infected when they feed on infected birds of the Corvid family, such as ravens, crows, jays and magpies. The mosquito can then transmit the infection to humans and animals by biting them. You cannot get the virus from another person or animal.

Symptoms of a West Nile Virus infection

Most people who become infected with the West Nile Virus (WNV) do not become ill. Only about twenty percent develop West Nile fever, which besides fever includes headache and body aches, and occasionally a rash on the trunk of the body and swollen lymph glands. Symptoms begin 3-14 days after the bite of an infected mosquito and in cases of mild disease last a few days. People with questions about WNV symptoms should call their health care provider.
Only about one out of 150 of those who become infected develop a severe infection, also known as West Nile encephalitis or meningitis. Symptoms range from headache, high fever, neck stiffness, stupor, disorientation, coma, tremors, convulsions, muscle weakness and paralysis. Symptoms of sever disease may last several weeks, although some brain and nerve damage may be permanent. There is no effective treatment for WNV infection other than supportive therapy, such as hospitalization, intraveneous (IV) fluids, airway management, respiratory support (ventilator) if needed, prevention of secondary infections (pneumonia, urinary tract, etc.), and good nursing care. The only effective strategy is prevention. Severe infection is rare and more common in people over 50.

Prevention

There are two basic prevention strategies: reducing the mosquito population and avoiding mosquito bites. The best way to reduce the mosquito population is to drain sources of standing water by early April. This will prevent mosquitoes from laying eggs and breeding.
  • At least once or twice per week empty water from flowerpots, pet food and water dishes, birdbaths, swimming pool covers, buckets, barrels and cans.
  • Check for clogged rain gutters and clean them out.
  • Remove discarded tires and other items such as cans, bottles and other containers that could collect water.
  • Be sure to check for containers or trash in places that may be hard to see, such as under bushes or under your home.
  • Cover boats or store them upside down or in a dry place.
  • Where feasible, fill all holes in the trees on your property.
  • When swimming season is over, empty and store wading pools in a dry place. Cover large pools and check frequently to ensure against mosquito breeding. Pool chemicals like chlorine at ordinary concentrations will not kill mosquito larvae. Keep the pool's water circulating and run filters April through October.
  • Check around faucets and air conditioner units and repair leaks and eliminate puddles that remain for several days.

Photo: www.west-nile-virus-prevention.com

Personal protection

  • Consider staying indoors at dawn, dusk, and in the early evening, which are peak mosquito biting times.
  • When possible, wear long-sleeved shirts and long pants outdoors.
  • Place mosquito netting over infant carriers.
  • Install or repair window and door screens.
  • Apply insect repellent containing DEET (N,N-diethyl-meta-toluamide) when you're outdoors. Be sure to read and follow the manufacturer's directions for use as printed on the product. Alternatively, spray clothing with DEET since mosquitoes may bite through thin clothing. If you spray your clothing there is no need to spray repellent containing DEET on the skin under your clothing.
  • Repellents may irritate the eyes and mouth, so avoid applying repellent to the hands of children.
  • Call the Baker County Vector Control (541) 523-1151 to have Gambusia affinis (mosquito larvae eating fish) placed in your pond. This is a free service, but supplies are limited.

Detecting West Nile Virus in Baker County

Dead Corvid birds, such as crows, jays or magpies in an area may indicate that WNV is circulating between the birds and the mosquitoes in that area. The public can play an important role in helping to monitor for WNV. Baker County Health staff and Vector Control can pick up specimens. To reduce the cost and increase the efficiency of our detection system, use these criteria when requesting dead bird testing:
  • The birds should be Corvids (crows, jays, magpies, and ravens) that have been dead less than 24 hours.
  • Birds killed on the road, in parking lots, or deaths related to pesticide spraying or injuries from other animals will not be tested.
  • Baker County Health Department (541) 523-8211 or Vector Control (541) 523-1151 can provide information on how to collect the specimens.
  • Once WNV has been detected in Baker County, we may discontinue bird testing.

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