Boulder - West Nile virus (WNV) has been detected in two dead birds and one mosquito pool, according to test results received today. The birds, both magpies, were collected late last week - one in Lafayette, near the intersection of 109th Street and Jasper Road, and the second in Longmont, north of Highway 66 near Hover Road. The mosquitoes that tested positive were trapped on City of Boulder Open Space near the Boulder Reservoir. Laboratory confirmation was provided by the Colorado Department of Public Health and Environment (CDPHE). Fifty-nine specimens (39 birds, 16 mosquito pools and 4 horses) have tested positive for the virus in Colorado this summer, but this represents the first cases identified in Boulder County.

WNV first arrived in Colorado late last summer when 380 horses, 138 birds, and 14 humans tested positive for the virus. Boulder County escaped last season without a human case, but did have five birds and three horses test positive. All of last year's human cases have either already recovered or are still recovering.

The virus' return to Colorado this year was marked after a dead magpie found on June 4th in Fremont County subsequently tested positive. Heath Harmon, coordinator of Boulder County Public Health's Communicable Disease Control Program, said the reappearance of the West Nile Virus in Boulder County comes as no surprise.

"We expected to see the virus again this year, based on the patterns observed throughout the eastern U.S." Harmon said. "It was that expectation that prompted Boulder County Public Health (BCPH) to work closely with local municipalities to promote awareness among the county's residents to take precautions that will prevent exposures to mosquitoes and reduce the risk of severe illnesses caused by the West Nile virus."

Boulder County Public Health has implemented a surveillance program that monitors WVN activity throughout the county. The program tracks the testing of birds, mosquitoes, chickens, horses, and humans using geographic mapping systems (GIS). "The intent is to closely monitor the virus' activity by location and time, so that we can identify areas in the county where the risk to human infection may be high," Harmon said.

Joe Malinowski, coordinator of the BCPH Consumer Protection Program, said mosquito control has also become a priority in reducing the risk of infection by WNV. "The key to mosquito control is to identify mosquito-breeding areas and eliminate the mosquito larvae before they can hatch into the adult mosquito," said Malinowski. "Spraying pesticides to kill adult mosquitoes is seen as a last line of defense, and only makes up approximately 2% of control efforts."

CDPHE's laboratory in Denver and five regional public health laboratories are accepting birds for testing of West Nile Virus if they meet certain conditions. Not all dead birds are eligible or will be accepted for testing. To be eligible for WNV testing, a dead bird must meet the following criteria:

1. The bird must be a member of the corvid family. This includes crows, ravens, magpies, and jays.

2. The bird must have been dead less than 48 hours.

3. An exact location of where the bird was found must be available.

Birds such as sparrows, starlings, pigeons, finches, robins, small blackbirds, and songbirds will not be accepted for testing. Also, birds that are dried out, smelly, or infested with maggots cannot be tested and will be rejected. If multiple birds have already been sent in for testing from one area, additional birds from that area may not be needed.

Malinowski said if a bird meets the testing criteria, residents should contact Boulder County Public Health at 303-441-1180, or the local animal control agency for the area where the bird was located. Boulder County Public Health or animal control agency will determine if the bird is needed for testing and will advise the citizen on how the bird should be collected and submitted for testing. If the bird does not meet the criteria or is not needed for testing, the carcass should be disposed of in the trash.

Although the virus can cause serious illness, most infections are mild and go unnoticed, noted Harmon. "If symptoms are present, they usually include fever, headache, body aches, and occasionally a skin rash and swollen lymph glands. Severe infections are rare, but may cause headache, high fever, neck stiffness, disorientation, muscle weakness, paralysis, and in few cases, death."

"Individuals of all ages should take precautions to reduce the risk of being infected; however, persons over the age of 50 are at the greatest risk for developing severe illness and should be particularly prudent about protecting themselves. Persons experiencing more severe symptoms should contact their health care provider immediately," said Harmon.

Additional information about West Nile virus, mosquito prevention, and the mosquito control efforts throughout the county can be found at www.bouldercountymosqutio.net <http://www.bouldercountymosqutio.net>.

The Four "Ds" for Mosquito Prevention

DRAIN standing water around the house weekly since it's where mosquitoes lay eggs. This includes tires, cans, flowerpots, clogged rain gutters, rain barrels, puddles, garden equipment, pool covers, plastic sheeting, pet dishes, and kid's toys. DUSK & DAWN are when mosquitoes are most active, so limit outdoor activities. DEET is an effective ingredient in mosquito repellants. Apply a repellant containing 10-35% DEET to exposed skin or clothing. Always use less than 10% DEET on children, and always read the label and follow product directions. DRESS in long sleeves and pants while in areas where mosquitoes are active.