City waging war on West Nile Bats, goldfish will be pressed into duty by Jennifer Heibult Since the appearance of the West Nile Virus in the United States in 1999, there have been an increasing number of reported cases each year, and summer 2003 is not expected to be an exception.
The city of Vermillion is taking steps to protect citizens from the virus by going after the source of a potential outbreak � mosquitoes.
At a recent Vermillion City County meeting, City Manager James Patrick outlined actions the city of Vermillion may take to control mosquitoes in hopes of limiting the spread of the virus in the community.
Patrick said that the use of natural means will be implemented first and chemical agents will be used only if necessary.
Mosquito control is the best prevention because humans and animals, including horses, squirrels, cats, domesticated rabbits, chipmunks and birds are infected through mosquito bites.
The mosquitoes themselves become infected when they feed on birds that have high levels of West Nile Virus in their blood.
Although the general public's perception of bats is not a positive one, the use of bat houses will serve as the city's greatest natural defense against mosquitoes.
The Organization for Bat Conservation reports that bats are the primary predators of night-flying insects and play an important role in maintaining the balance of nature. One large brown bat, for example, is capable of eating 6,000 to 8,000 insects each night.
Also, contrary to popular belief, bats are actually very clean animals, do not eat through the attic of homes and will not interfere with feeding backyard birds.
The cost of additional bat houses to the city will be negligible with the help of an Eagle Scout who is constructing the houses.
A bat house is simply made by placing a cedar box outside 15 to 20 feet high; it may be attached to a tree or pole. It is recommended by the Organization for Bat Conservation that the box be placed in an area that will receive at least six hours of sun a day to serve as a means of incubation for young. To provide additional warmth, a layer of black paint to the outside only of the cedar box is advised.
The city will also soon be stocking golf course lakes with goldfish, thereby controlling algae and mosquito larvae.
Standing water is a breeding ground for mosquito larvae, therefore the city will use organic pellets (Vectolex CG or Bti) in problem areas. Patrick said the city has already begun to purchase the pellets and will use them as soon as needed.
The cost is estimated at approximately $10,000 to treat standing water in the city, including bypass road ditches and other parks. Side effects involved in the use of the pellets are minimal because of its organic nature. The pellets are non-toxic to fish and pose no threat to humans unless they are standing in the water.
Fogging is a step the city prefers not to take, but is prepared to do so if the area becomes a high risk to West Nile. Fogging would be more costly and entail the discharge of a chemical mist in the evenings along bike trails, water ways, parks and golf courses.
Patrick reiterated the city's concern with public safety stating. "No neighborhoods will be fogged," he said.
The city is also considering the use of the insecticide spray Tempo as an option for West Nile Virus control. Spraying, however, would be done only as a last resort.
The insecticide would be applied in the morning directly to grass on softball and soccer fields.
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Patrick said that in all cases of prevention, "education of the public is a priority and public notices will be placed where appropriate.
"Last year this area was designated a high risk for the West Nile Virus," he said, but he added it is necessary to keep the actual effects of the disease in perspective.
The Centers for Disease Control and Prevention reported 277 deaths around the country last year due to the disease in contrast to 20,000 people who die of the flu each year.
The West Nile Virus has been found in Africa, Eastern Europe, West Asia and the Middle East, but until the summer of 1999, it had not been documented in the Western Hemisphere.
In 2002, the CDC reported 3,852 human cases. Although 44 states in the U.S. reported cases of the West Nile virus, not all documented West Nile infections occurred in humans.
An estimated one in 150 people infected will develop symptoms that are more serious than the typical flu-like symptoms. These severe cases are West Nile encephalitis, West Nile meningitis or West Nile meningoencephalitis, which causes an inflammation of the membrane around the brain and spinal cord.
This illness is accompanied often by high fever, disorientation, coma, tremors, convulsions, neck stiffness, muscle weakness and paralysis that may result in death, according to the CDC.
The incubation period for humans infected with this severe case is usually three to 14 days, and the risk of serious illness is greater for older people and those with compromised immune systems. There is no medication or vaccine specific to the treatment or prevention of West Nile Virus.
A noticeably high number of dead birds, particularly crows and jays, in the community this summer may indicate that West Nile is present.
Actions to reduce mosquito breeding opportunities, such as cleaning bird baths and rain gutters, emptying unused buckets and the removal of standing water where some species of mosquitoes may reproduce in only a week's time, are beneficial.
Wearing repellent and long shirts and pants during hot South Dakota summers, especially in late summer and early fall when cases have been most prominent, is also an option.