West Nile Virus – America’s New Threat.
edited: Thursday, September 05, 2002
By Karen Phillips
Posted: Friday, August 16, 2002
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West Nile Virus - Prevention and symptoms
Medicine Woman Herbals
West Nile Virus – America’s New Threat.
Several cases of this potentially deadly virus have been detected recently in the United States.
West Nile Virus has emerged in recent years in temperate regions of Europe and North America, presenting a threat to public, equine, and animal health. The most serious manifestation of West Nile Virus infection is fatal encephalitis (inflammation of the brain) in humans and horses, as well as mortality (death) in certain domestic and wild birds.
Encephalitis is an inflammation of the brain and can be caused by viruses and bacteria, including viruses transmitted by mosquitoes. West Nile encephalitis is an infection of the brain caused by West Nile Virus, a flavivirus commonly found in Africa, West Asia, and the Middle East. It is closely related to St. Louis encephalitis virus found in the United States. The incubation period for this virus is usually 3 to 15 days.
West Nile Virus has been commonly found in humans and birds and other vertebrates in Africa, Eastern Europe, West Asia, and the Middle East, but until 1999 had not previously been documented in the Western Hemisphere. It is not known from where the United States virus originated, but it is most closely related genetically to strains found in the Middle East.
It is not known how long it has been in the United States, but CDC scientists believe the virus has probably been in the eastern United States since the early summer of 1999, possibly longer. Recent cases have been detected in Louisiana, Tennessee, Kentucky, and other eastern states. At least one of the cases in Louisiana proved fatal.
In 1999, 62 cases of severe disease, including 7 deaths, occurred in the New York area. In 2000, 21 cases were reported, including 2 deaths in the New York City area. No reliable estimates are available for the number of cases of West Nile encephalitis that occur worldwide.
One of the species of mosquitoes found to carry West Nile Virus is the Culex species, which survive through the winter, or “over winter”, in the adult stage. That the virus survived along with the mosquitoes was documented by the widespread transmission the summer of 2000.
The continued expansion of West Nile Virus in the United States indicates that it is permanently established in the Western Hemisphere.
In the temperate zone of the world, West Nile encephalitis cases occur primarily in the late summer or early fall. In the southern climates where temperatures are milder, West Nile virus can be transmitted year round.
People get West Nile Virus by the bite of mosquitoes infected with the virus.
Mosquitoes become infected when they feed on infected birds, which may circulate the virus in their blood for a few days. Infected mosquitoes can then transmit West Nile virus to humans and animals while biting to take blood. The virus is located in the mosquito’s salivary glands. During blood feeding, the virus may be injected into the animal or human, where it may multiply, possibly causing illness.
One mosquito bite is not likely to cause illness. Even in areas where mosquitoes do carry the virus, very few mosquitoes—much less than 1%--are infected. If the mosquito is infected, less than 1% of people who get bitten and become infected will get severely ill. The chances you will become severely ill from any one mosquito bite are extremely small unless you have an already weakened immune system. Weakened immune systems are common in persons around age 50.
West Nile encephalitis is NOT transmitted from person-to-person. For example, you cannot get West Nile Virus from touching or kissing a person who has the disease, or from a health care worker who has treated someone with the disease.
Infected mosquitoes are the primary source for West Nile Virus. Although ticks infected with West Nile Virus have been found in Asia and Africa, their role in the transmission and maintenance of the virus is uncertain. However, there is no information to suggest that ticks played any role in the cases identified in the United States.
Although the vast majority of infections have been identified in birds, West Nile Virus has been shown to infect horses, cats, bats, chipmunks, skunks, squirrels, and domestic rabbits.
There is no evidence that a person can get the virus from handling live or dead infected birds. However, persons should avoid bare-handed contact when handling any dead animals and use gloves or double plastic bags to place the carcass in a garbage can.
Infectious mosquitoes transmit West Nile virus. There is no documented evidence of person-to-person or animal-to-person transmission of West Nile Virus. Normal veterinary infection control precautions should be followed when caring for a horse suspected to have this or any viral infection.
Following transmission by an infected mosquito, West Nile virus multiplies in the person’s blood system and crosses the blood-brain barrier to reach the brain. The virus interferes with normal central nervous system functioning and causes inflammation of brain tissue.
Encephalitis is an inflammation of the brain. There are many types of encephalitis, most of which are caused by viral infection. Symptoms include sudden fever, headache, body aches, occasionally with skin rash, vomiting, photophobia (abnormal visual sensitivity to light), stiff neck and back, confusion, drowsiness, clumsiness, unsteady gait, swollen lymph glands, and irritability. Symptoms that require emergency treatment include loss of consciousness, poor responsiveness, neck stiffness, stupor, disorientation, coma, seizures, muscle weakness, paralysis, sudden severe dementia, memory loss, withdrawal from social interaction, impaired judgment, and, rarely, death. Anyone experiencing symptoms of encephalitis should contact their health care professional immediately.
Among those with severe illness due to West Nile Virus, case-fatality rates range from 3% to 15% and are highest among the elderly. Less than 1% of those infected with West Nile Virus will develop severe illness.
After recovery from West Nile Virus it is assumed that immunity to reinfection is lifelong; however, it may wane in later years.
There is no vaccine at this time against the West Nile Virus.
All residents of areas where virus activity has been identified are at risk of getting West Nile encephalitis; persons older than 50 years have the highest risk of severe disease. To lessen the possibility of contracting this virus you may find it beneficial to take Astragalus to strengthen your immune system. You should also follow the guidelines for preventing mosquito infestation around your home. Catnip oil has been found to be beneficial in repelling mosquitoes thereby lessening the chance of being bitten. Medicine Woman Herbals is offering a new product by the name of Skeeter Gone. This product is Catnip oil. I personally find this product beneficial as a repellant.
I hope that I have answered all your questions about this potential threat. Further questions will be addressed through the Contact an Herbalist link on my web page at http://www.grannyherb.com/. You will also find a complete product line of pure extracts.
We can rely on The Wisdom of our Ancestors© to bring us through this potential threat.
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