City Targeting Mosquitoes

Jun 13, 2007 - 16:27:43 CDT.

Relief is on the way for area residents who are tired of swatting one blood-sucking, potentially-disease-carrying mosquito after another and who are ready to proclaim the mosquito as Public Enemy No. 1. That’s because the City of Fredericksburg has begun to fight back against the recent infestation brought on by an unusually rainy Spring season. And, officials are urging residents to do the same because it takes a true community effort to defeat the flying pests.

As of the end of last week, workers within the city’s street department and the parks and recreation department began distributing “Mosquito Dunks” (larvicide treatments) at the source of the problem -- stagnant pools of water where mosquitoes breed and the “wigglers” grow and develop into the winged hunters that often bombard unsuspecting victims of all ages at outdoor parties, picnics and ballgames. The donut-shaped larvicide discs are designed to float and provide sustained release for long-term control of mosquito larvae.

“The primary areas that we’ll be looking at to treat are the parks and also some of the regional detention ponds that aren’t privately owned by citizens,” reported City Manager Gary Neffendorf, who added that while spraying is the most effective way to treat mosquitoes already in the air, the city hasn’t done that since the 1970s because the Mosquito Dunks are a safer route, environmentally-speaking.

In addition, over the past few days, city crews have been canvassing public-access areas in search of areas where rainwater has collected so that they may clear those areas out and eliminate potential mosquito breeding spots.

“The best thing we can do is look for ponding water. We turn to the trash cans and empty them as well as buckets -- anything that can have standing water in it,” Neffendorf said.

“We’ve always looked at mosquito control as a safety and welfare issue and so we’ve always done something to try to control it,” he added.

The health and safety is also at the forefront of city/county sanitarian officer Kelli Olfers’ mind. “With the wonderful rains we have had this spring, unfortunately that brings large numbers of mosquitoes to our area. Gillespie County residents can protect themselves by draining standing water around their homes, limiting the time spent outdoors between dusk and dawn and keeping themselves covered with clothing, as well as using a recommended repellent on exposed skin,” she added.

In addition, homeowners are reminded to repair screens to help keep mosquitoes from entering indoors to find their prey.

What’s at stake is more than just itchy whelps and painful bites from feeding female mosquitoes. (Males only feed on nectar, plant juices and other sources of liquid carbohydrates.) The blood-drinkers can carry and spread a number of diseases, including encephalitis, dengue fever, yellow fever and malaria, which has been recognized by the Centers for Disease Control (CDC) as a major international public health problem responsible for one million deaths annually.

More recently, the mosquito has become synonymous with the infamous West Nile Virus, from which 33 fatalities were reported in Texas last year alone, according to the Texas Department of State Health Services.

“West Nile virus first appeared in Texas in June 2002 and has since moved across the state,” said Joe Garrett, a veterinarian with the zoonosis control division at the Texas Department of Health (TDH). “We probably should consider West Nile virus endemic to the state now.”

Mosquitoes get the West Nile virus by biting infected birds and then can spread the virus by biting people or animals. The TDH Laboratory annually tests mosquitoes and dead birds (generally jays, crows and hawks) as a way of actively tracking the virus to alert affected communities that they may need to take precautions to protect themselves, Garrett said.

“Currently the risk of someone here contracting a disease such as West Nile virus is relatively small, but protecting yourself from bites is the key to preventing any mosquito-borne disease,” Mrs. Olfers said.

Worldwide, there are 2,700 species of mosquitoes, including one aptly named “Tormentor”. Of that population, only about 100 carry diseases.

The most serious manifestation of West Nile Virus infection is fatal encephalitis (inflammation of the brain). According to the CDC, about one in 150 people infected with WNV will develop severe illness characterized by headache, high fever, neck stiffness, stupor, disorientation, coma, tremors, convulsions, muscle weakness and paralysis. Milder cases involve fever, headache, body aches and occasionally a skin rash on the trunk of the body and swollen lymph glands.

Most people (80 percent) infected by a WNV-carrying mosquito will not develop any symptoms at all.

Still, the risk of severe illness and death does exist and is highest for those 50 years of age and older.

The incubation period for West Nile virus is three to 14 days. Mild symptoms may last a few days while symptoms of more severe illness may last several weeks and neurological effects may be permanent and even fatal.

Currently, there is no vaccine available to combat West Nile Virus in people and no specific treatment given for the infection other than supportive therapies for fever or pain.

Still, “people can, however, do a great deal to protect themselves, their families and their communities,” said Dr. Eduardo Sanchez, while formerly serving as the Texas Commissioner on Health. “Reducing exposure to mosquitoes is one of the most important things.”

He urged people to remember the four “D”s --

•Dusk to Dawn. Stay indoors from dusk to dawn, times when mosquitoes likely carry infection are most active.

•Dress. Be sure to wear long sleeves and pants, particularly while outside in mosquito-infested areas.

•DEET. Apply insect repellent that contains the ingredient DEET. Read and follow label instructions. Spray both exposed skin and clothing.

•Drain. Get rid of standing water in the yard or neighborhood. Old tires, flower pots, clogged rain gutters, leaky pipes and faucets, birdbaths, cans, bottles, old pieces of plastic and wading pools can all be prime breeding sites for mosquitoes.

For more information about West Nile Virus, visit the TDH website at www.tdh.state.tx.us or the CDC website at www.cdc.gov/ncidod/dvbid/westnile/index.htm.

In addition to causing health problems in the human population, mosquitoes can be deadly for horses and be a big source of heartworm troubles in dogs. Heartworms lead to circulatory problems with symptoms such as coughing, labored breathing and general loss of vitality in advanced stages. Pet owners are reminded to treat their dogs for heartworms regularly.