Other Links ......... Illinois State..
West Nile Virus in Illinois
On Wednesday, September 5, 2001, two crows from Cook and DuPage Counties were confirmed as being positive for West Nile virus (WNV). This is the first time this disease has been diagnosed in Illinois. It has also been diagnosed in 21 other states and Canada, including Wisconsin, Michigan, Indiana and Kentucky.
What species are affected by WNV?
Humans, equidae and wild birds are most commonly affected by WNV. There have been no confirmed cases in livestock in the United States.
How is the disease spread?
Wild birds represent the reservoir for this virus, which is transmitted by mosquitoes. After a mosquito bites an infected bird, the virus is retained in the mosquito's salivary glands. When the insect bites or feeds on a human or a horse, the virus is injected into the blood system where it multiplies and may cause the illness. Horses and humans are incidental hosts of WNV and therefore cannot transmit the disease.
What are the symptoms of WNV?
Horses and other equidae will exhibit listlessness, stumbling and incoordination, weakness of limbs, ataxia, partial paralysis or death. A fever is not usually observed. Treatment would be supportive and consistent with standard treatment for animals infected with a viral agent. In humans, the most common symptoms are a fever and headache, but can include a rash, swollen nodes and conjunctivitis. In severe cases, the symptoms include the rapid onset of severe headache, high fever, stiff neck, disorientation, muscle weakness, coma or death.
Is the disease fatal?
During the outbreak in 2000, 36 percent of the affected horses died or were euthanized. It is likely that horses recover from the infection without ever showing clinical signs of illness. Since horses are incidental hosts, affected animals do not need to be quarantined or euthanized. Through August 22, 2001, there have been 35 confirmed clinical cases in horses with 12 fatalities. The disease can also be fatal in humans. As of September 6, 2001, one human fatality has been reported in Georgia.
Is WNV a reportable disease?
Yes, WNV is a reportable disease in Illinois, as it is currently considered to be a foreign animal disease (FAD). Reported suspect cases will be handled as a FAD. If you suspect WNV in a horse, please contact the Illinois Department of Agriculture, Bureau of Animal Health 217/782-4944 or the USDA/APHISNS office 217/241-6689 immediately. Dead birds, especially crows, blue jays and hawks, should be reported to the Illinois Department of Public Health 217/782-5830 or the Illinois Department of Natural Resources 217/782-6384.
How can I protect animals and myself?
Preventing exposure to mosquitoes is essential. One of the best ways to do this is by removing any potential sources of water in which mosquitoes can breed. This includes:
o Disposing of water-holding containers, including discarded tires oDrilling holes in the bottom of containers that are left outside
o Cleaning clogged roof gutters
o Turning over plastic wading pools or wheelbarrows when not in use and do not allow water in bird baths to become stagnate
o Aerating ornamental pools or stocking them with fish
o Cleaning and chlorinating swimming pools that are not in use and being aware that mosquitoes can breed in the water that collects on swimming pool covers
o Landscaping property to eliminate standing water as mosquitoes can breed in any puddle that lasts more than four days oCleaning of livestock-watering troughs thoroughly on a monthly basis Prevention for horses include:
o Insect-proofing stables
o Using insect repellant containing DEET oKeeping animals inside during peak mosquito feeding hours (sunset to sunrise)
o Avoiding mosquito prone areas such as swampy areas and heavily forested areas
o Vaccinating animals
o Using fans may reduce the potential ability of mosquitoes to feed on horses Prevention for humans include: oUsing insect repellant containing DEET
o Wearing long sleeves and pants when out-of-doors
o Avoiding mosquito prone areas such as swampy areas and heavily forested areas, especially between sunset and sunrise
Is the vaccine available in Illinois?
Fort Dodge Laboratories received a conditional license for a killed virus product on August 1, 2001. Conditional licensing means that the product has been shown to be safe, pure, and have a reasonable expectation of efficacy in preventing illness. On August 7, IDOA approved the sale of this vaccine to licensed veterinarians in Illinois. The vaccine can only be administered by a veterinarian. Fort Dodge recommends administering two 1 milliliter intramuscular doses, three to six weeks apart, followed by an annual booster.
The vaccine is in short supply, but Fort Dodge is supposed to release more of the vaccine on September 18, 2001. They are hopeful that this release will meet the demand.