LABORATORY POSITIVE HUMAN CASES – 14
HUMAN DEATHS – 0
POSITIVE HORSES – 378
POSITIVE DEAD BIRDS – 131
POSITIVE CHICKENS (FROM SENTINEL FLOCKS) – 3
POSITIVE MOSQUITO POOLS – 15

IN DENVER;

LABORATORY POSITIVE HUMAN CASES – 1
HUMAN DEATHS – 0
POSITIVE HORSES – 0
POSITIVE DEAD BIRDS - 15
POSITIVE MOSQUITO POOLS – 0

In Colorado, the first West Nile positive bird was found on 8/5/02, the first positive horses was found on 8/13/02, and the first positive human case was found on 9/3/02 (a 42-year-old man from Commerce City).

In Denver, the first West Nile positive bird was found on 8/21/02 and the first positive human cases was reported on 10/29/02 (a 39-year-old man).

Denver collected 121 birds that were sent in for testing, of these 89 were tested. Of the 89 tested 74 were negative, and 15 were positive for West Nile Virus. Of the 15 positive birds, 7 were crows, 6 were magpies, 1 was a finch, and 1 was a Chilean flamingo (from the Denver Zoo).

Dogs, cats, raptors (eagles, hawks, great horned owls), eastern chipmunks, gray squirrels, raccoons, wolves, striped skunks, mountain goats, Suffolk sheep, reindeer, alligators, bats, domestic rabbits, and over 140 species of birds including cockatiel, parakeet, cockatoo, macaw, peacock, emu, flamingo, penguin, and domestic turkey.

"West Nile Virus" is a flavivirus commonly found in Africa, West Asia, and the Middle East. It was first found in the United States in 1999 and by the end of 2002, West Nile virus has been found in 44 states and Washington D.C. It is closely related to St. Louis encephalitis virus that has been found in the United States for years, and both are transmitted from infected birds to man by the bite of an infected mosquito.

"West Nile fever" is a case of mild disease in people, characterized by flu-like symptoms. West Nile fever typically lasts only a few days and does not appear to cause any long-term health effects.

More severe cases of a person being infected with West Nile virus can lead to "West Nile encephalitis", "West Nile meningitis" or "West Nile meningoencephalitis". Encephalitis refers to an inflammation of the brain, meningitis is an inflammation of the membrane around the brain and the spinal cord, and meningoencephalitis refers to inflammation of the brain and the membrane surrounding it.

Death is caused by the damage from the more sever cases of West Nile meningoencephalitis and the percentage of those who die, for the most part, goes up with age. Below is the death percentage by age group for West Nile meningoencephalitis in the United States:

Most people who are infected with the West Nile virus will not have any type of illness. It is estimated that 20% of the people who become infected will develop West Nile fever: mild symptoms, including fever, headache, and body aches, occasionally with a skin rash on the trunk of the body and swollen lymph glands.

Less than 1% of persons infected with West Nile virus will develop severe illness. The symptoms of severe infection (West Nile encephalitis or meningitis) include headache, high fever, neck stiffness, stupor, disorientation, coma, tremors, convulsions, muscle weakness, and paralysis. It is estimated that 1 in 150 persons infected with the West Nile virus will develop a more severe form of disease.

The symptoms of West Nile virus will usually show up 3 to 14 days after being infected. Symptoms of the mild disease will generally last a few days, whereas, symptoms of the severe disease may last several weeks and the neurological effects may be permanent.

The principle route of human infection with West Nile virus is through the bite of an infected mosquito. Mosquitoes become infected when they feed on infected birds, which may circulate the virus in their blood for a few days. The virus eventually finds its ways into the mosquito’s salivary glands. During subsequent blood meals, the virus may be injected into humans and animals, where it can multiply and possibly cause illness.

Additional routes of infection have become apparent during the 2002 West Nile epidemic. It is important to note that these other methods of transmission represent a very small proportion of cases. These include organ transplants, blood transfusions, laboratory works becoming infected from percutaneous inoculation (pierced through the skin) and one case of transplacental (mother-to-child) WNV transmission. There is one case still being studied to see if a newborn got West Nile virus from his mother’s breast milk.

West Nile virus is NOT transmitted from person-to-person. For example, you can not 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.

There is no documented evidence of animal-to-person transmission of West Nile virus. Normal veterinary infection control precautions should be followed when caring for a horse suspected of this or any viral infection.

There is no evidence that a person can get the virus from handling live or dead infected birds. However, persons should avoid barehanded contact when handling any dead animals and use gloves or double plastic bags to place the carcass in a garbage can.

There is no scientific evidence indicating that people can be chronically infected with West Nile virus. What remain in a person’s body for long periods of time are antibodies and "memory" white blood cells (T-lymphocytes) that the body produces to the virus. These antibodies and T-lymphocytes last for years, and may last for the rest of a person’s life providing future immunity to West Nile virus. It is assumed that this immunity will be lifelong; however, it may wane in later years.

Preventive measures that you and your family can take:

1. Protect yourself from mosquito bites:

• Apply insect repellent sparingly to exposed skin. The more DEET a repellent contains the longer time it can protect you from mosquito bites. A higher percentage of DEET in a repellent does not mean that your protection is better – just that it will last longer. DEET concentrations higher than 50% do not increase the length of protection. Choose a repellent that provides protection for the amount of time that you will be outdoors.
  
  
• Repellents may irritate the eyes and mouth, so avoid applying repellent to the hands of children.
  
  
• Whenever you use an insecticide or insect repellent, be sure to read and follow the manufacture’s DIRECTION FOR USE, as printed on the product.
  
  
• Spray clothing with repellents containing permethrin or DEET since mosquitoes may bite through thin clothing. Do not apply repellents containing permethrin directly to exposed skin. If you spray your clothing, there is no need to spray repellent containing DEET on the skin under your clothing.
  
  
• When possible, wear long-sleeved shirts and long pants whenever you are outdoors.
  
  
• Place mosquito netting over infant carriers when you are outdoors with infants.
  
  
• Consider staying indoors at dawn, dusk, and in the early evening, which are peak mosquito biting times.
  
  
• Install or repair window and door screens so that mosquitoes cannot get indoors.

2. Help reduce the number of mosquitoes in areas outdoors where you work or live, by draining sources of standing water. In this way, you reduce the number of places mosquitoes can lay their eggs and breed.

• At least once or twice a week, empty water from flower pots, pet food and water dishes, birdbaths, swimming pool cover, buckets, barrels, and cans.
  
  
• Check for clogged rain gutters and clean them out. Remove standing water from flat roofs.
  
  
• Remove discarded tires, and other items 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.
  
  
• Drill holes in the bottoms of recycling containers.
  
  
• Check around faucets and air conditioner units and repair leaks or eliminate puddles that remain for several days.
  
  
• Aerate ornamental pools or stock with fish.
  
  
• Clean and chlorinate swimming pools when not in use.
  
  
• Check around construction sites or do-it-yourself improvements to ensure that proper back filling and grading, to prevent drainage problems.
  
  
• Alter the landscape of your property to eliminate standing water. Keep in mind that during warm weather, mosquitoes can breed in any puddle of water.
  
  
• Consider using larvicides when standing water cannot be eliminated.

Note: Vitamin B and "ultrasonic" devices are NOT effective in preventing mosquito bites.