Mosquito hunters headed to mountains |

Mosquito hunters headed to mountains

Veronica Whitney

Efforts to ward off West Nile virus, the disease that killed 62 people in Colorado last year and sickened one person in the valley, will intensify in the mountains this spring and summer.Following a tougher policy, crews will target mosquito habitats and breeding grounds and trap adult insects. County officials also plan to continue an education campaign against the disease, which encourages residents to wear insect repellent that contains the chemical DEET, considered effective in warding off bug bites. Additionally, Eagle County has signed a $154,000-contract with a Golden-based company that will search for mosquitoes carrying the virus in Eagle County.”The fact is, very few people wear insect repellent,” said Ray Merry, director of environmental health for Eagle County. “This is a small price to show the public that we’re being extremely responsible.”County officials said they expect more cases of the disease during this summer, West Nile virus’ second in the mountains. Throughout the country, the disease has been more severe the second year it has spread in an area.Eagle County reported its first human case of West Nile virus last August when a blood sample obtained from an Edwards’ woman tested positive for West Nile fever, the most common and milder form of the mosquito-born disease. West Nile virus is a mosquito-borne disease that can cause the brain and spinal cord to swell. Mosquitoes spread this virus after they bite infected birds and then bite people, other birds and animals. It is not spread by person-to-person contact and there is no evidence that people can get the virus by handling infected animals.Although no more human cases were reported in 2003, two horses died of West Nile virus in Eagle County in the fall. The new program in Eagle County will include:• Mapping and surveying of mosquito infestations.

• Surveillance of breeding sites.• Trapping adult mosquitoes and sending them for testing. Depending on any evidence of the virus, spraying could be recommended. “It’s a very effective program,” said Ed Fleming, an aquatic biologist who will spearhead the West Nile program in Eagle County. Fleming has contracts with five different clients on the Front Range, where the virus hit the hardest last summer, he said. “In Boulder, we killed 95 million of larvae last year,” he said. “There were habitats where we would have to do larva control every week.”The culex tarsalis mosquito is the primary carrier of West Nile virus, but isn’t common above 8,000 ft., Fleming said.”We don’t know if the culex tarsalis is prevalent here,” Fleming said. “But we will gain knowledge of what habitats and species there are.”Information gathered during the study will likely be shared with the towns in the county. The study should be the most intensive part of the county’s prevention campaign, Merry said. “We will have education; surveillance, and abatement of larvae,” he said. “Hopefully, we won’t need to spray.”In Garfield County, county officials have hired a company to do a similar job this year. So far, the company has mapped about 650 sites there where the insects are likely to breed.Last year, Colorado had the most cases of West Nile virus in the country with 2,947. That included 2,325 cases of fever, 389 of meningitis and 233 of encephalitis, according to the Colorado Department of Public Health and Environment. Most of the cases in Colorado were among people aged 45 to 49.The Centers for Disease Control and Prevention reports there were 9,858 cases and 262 deaths in the United States last year.

Although there’s no West Nile vaccine for humans, there is one available for horses and local veterinarians recommend horse owners vaccinate their horses.Veronica Whitney can be reached at 949-0555, ext. 454 or at ==========================================West Nile virus factsThe symptoms• People with mild infections may experience fever, headache, body aches, skin rash and swollen lymph glands – this is called West Nile fever. • People with more severe infections may have high fever, headaches, neck stiffness, stupor, disorientation, tremors, occasional convulsions and paralysis; and some fall into comas – this is called West Nile encephalitis. If you have any of these symptoms, contact your doctor.

How do humans get West Nile?The principle route of human infection is from the bite of an infected mosquito. The majority of the people who get infected with the virus have no illness or at most, have an infection similar to a mild flu with fever, headache and fatigue.Only certain species of mosquitoes carry the virus. The culex tarsalis is the only mosquito that carries the virus in Colorado. The culex tarsalis mosquito will feed on anything, including horses, birds and humans.Health officials believe one reason the disease is spread so rapidly in Colorado last summer is because of the culex tarsalis’ feeding habits.Prevention• Avoid outdoor activities – such as gardening – at dusk and dawn when mosquitoes are most active.• If outside during the periods when mosquitoes are most active, cover up by wearing long-sleeved shirts, pants, shoes and socks.• Use mosquito repellents with the chemical DEET. Products with 10 percent or less DEET are recommended for children.• Eliminate standing water in tires or similar water-holding containers as these may serve as mosquito-breeding sites. Change the water in birdbaths at least weekly.Source: Colorado Department of Public Health and Environment. On the Web:

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