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Source: Greg Clark, Unit Educator, Crop Systems, 815-772-4075 West Nile Virus (WNV) is a viral disease previously seen only in Africa, Asia, and Southern Europe. This virus can cause encephalitis, an inflammation of the brain and the spinal cord. For the past few years, WNV has caused disease in the United States.
The West Nile Virus is mainly spread to people by the bite of an infected mosquito. The principal transmitter of West Nile Virus is the Northern House Mosquito (Culex pipiens).
Mosquitoes first become exposed to the virus when they feed on birds that are infected with WNV. Once the mosquito is infected, it may transmit the virus to people or other animals when it bites them. Many birds can be infected with WNV, but crows and blue jays are most likely to die from the infection.
Horses, too, are prone to severe WNV infection. People cannot get WNV from direct contact with another person or horse that has the disease.
Continued spread of this disease among wild birds and mosquitoes is anticipated. In Illinois, state, federal, and local agencies are working together to address the potential health risks of WNV to Illinois families and their animals.
Illinois public health officials continue to find WNV in crows, blue jays, mosquitoes and horses. When WNV is found, mosquito control efforts are increased in those areas to protect people from the disease. In 2004, the number of West Nile human cases in Illinois was much lower than 2002 with 60 reported and four deaths. West Nile virus activity in 2004 was detected in 64 Illinois counties.
What Farmers Should Know About West Nile Virus
Who is most at risk?
People over 50 years of age have the highest risk of developing severe illness because as we age, our bodies have a harder time fighting off disease. People with compromised immune systems are also at risk. However, anyone can get the virus.
What are the symptoms?
People with mild infections may experience fever, headache, body aches, skin rash, and swollen lymph glands. People with more severe infections may experience high fever, headache, neck stiffness, stupor, disorientation, coma, tremors, occasional convulsions, paralysis, and rarely death. If you have any of these symptoms, contact your doctor.
Is there treatment?
There is no specific treatment for West Nile virus infection. While most people fully recover from the virus, in some severe cases hospitalization may be needed. There is currently no recommended vaccine to prevent WNV.
Is my farm a mosquito-breeding site?
Several habitats found on farms can support the production of mosquitoes. Larvae can develop in watering troughs, small ponds, irrigation ditches, rain barrels, manure lagoons, ruts where farm equipment frequently travels, and other areas where water is allowed to accumulate and allowed to stagnate for as few as four days.
Even hoof prints can accumulate water and provide a breeding habitat. The close proximity of livestock, nuisance animals (such as birds), and other animals to mosquito breeding habitats increases the risk for the transmission of animal and human disease.
What should I do about birds (both alive and dead) on my farm?
Remove all house sparrow, starling and pigeon nests from farm buildings. Periodically look around the property for dead birds, such as crows. Use gloves or an implement, such as a shovel, to handle dead birds.
How can I prevent mosquitoes from breeding?
There are many ways to eliminate mosquito-breeding areas on farms. Reducing standing water is the ultimate goal. Anything that collects water has the potential to provide mosquitoes the perfect breeding ground.
Improve drainage in areas that are irrigated or flooded, or use gravel to fill in ruts where farming equipment frequently travels. Fill depressions or tile areas that frequently are left filled with water after rains. Make sure ditches and culverts drain after rainstorms. Empty and clean watering troughs regularly. Troughs and watering tanks that develop scum are more likely to be mosquito breeding grounds.
Turn over farm equipment, wheelbarrows, buckets, barrels, and tanks when not in use.
Check the gutters on buildings. They should drain quickly after a rain. Clean gutters and downspouts regularly to prevent the accumulation of leaves and other debris that might clog them.
Remove or frequently empty any containers that accumulate water, including discarded tires and old equipment. Poke holes in or flatten cans and containers that cannot be removed or discarded immediately. Use garbage cans with lids and plastic liners for storing trash.
Where the farm uses tires to maintain the plastic on silos, the tires should be split, pierced or treated with larvicides. Aerate small ponds and stock them with surface eating fish such as goldfish, minnows and Gambusia, if game fish are not present.
Mosquitoes can also be controlled as larvae in water with insecticides. Bacillus thuringiensis israeliensis, a bacteria-based toxin that kills only the larvae of mosquitoes and closely related insects, is available in some garden centers. Bacillus sphaericus (Bs) may work better in the nasty, sewage-like water that the house mosquitoes prefer. Make sure to read and follow all label directions for use.
Make sure that doors and windows have tight-fitting screens. Repair damaged screens. Caulk around loose fitting doors and windows.
Store boats covered or upside down.
Keep weeds and grass mowed short, especially around downspouts, ditches, ponds and other water-collecting areas.
Remind or help neighbors to eliminate breeding sites on their properties.
Check on the elderly regularly.
Avoid being outside between dusk and dawn, when mosquitoes are likely to be biting.
When outdoors, wear light-colored clothing, long-sleeved shirts or jackets, long slacks, socks and shoes.
Use mosquito repellent containing DEET according to label directions (no more than 30 percent DEET for adults and 10 percent or less for children). This may be the most practical step when temperatures preclude long-sleeved shirts and jackets.
by Editor, theCity1.com
August 31, 2005
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