Vector-borne Disease Prevention

Vector Control Program Goal

To prevent the spread of disease from vectors to humans.

A vector is an organism (e.g. fly, tick, mosquito, etc.) that transmits disease germs. The main vectors of concern in Boulder County are prairie dog fleas, which can carry plague, and mosquitos, which can carry Western Equine Encephalitis, St. Louis Encephalitis, and West Nile virus.

Animals in Your Residence and What You Can Do About It

Skunks

Some favorite skunk hideouts are foundations of houses or basements. The most effective control for skunks is to bury wire mesh 18"underground around these structures, or use sheet metal or concrete to seal access points. Skunks don't like loud noise or light; therefore, you can also try to shine a light into their hiding places.

Remember, animals are attracted to food and harborage. If you eliminate these, you should eliminate the problem.

TIP: If a skunk is living under your house or building, put a nylon stocking full of mothballs under your house and attach a long string to it (so you can get it back). Cover the ground at the entrance with soil or flour. Close the entrance with hardware cloth once you see tracks showing the animal has left (best to check in a.m.). If no more tracks appear, permanently seal the hole.

Bats

Bats carry rabies and should not be handled. Rabies is almost invariably a fatal and acute viral disease. Bats can find their way into houses, causing odors, noise, and nuisance conditions. Bats can fit through cracks 1/4" wide. The best prevention is to ensure all cracks around your structure are well sealed. If bats are found, the only way to rid them is to seal off their entrance to your residence when they are out foraging at night.

Do not attempt to handle bats with bare hands; open doors and windows so they can fly out. If bitten or scratched by a bat, contact your physician or local medical emergency clinic and Boulder County Public Health at (303) 441-1564.

Clean the injured area with soap and water immediately and apply alcohol or iodine. If the bat is not "captured," you will need preventative treatment immediately. Make a reasonable attempt to capture the bat, taking precautions with heavy gloves or tongs and do not damage the bat's head.

If your pet catches a bat or you find one in your house, contact Boulder County Public Health at 303-441-1564 to determine if testing is necessary.

Bats flying around outside are not a problem, as they consume lots of nuisance insects, such as mosquitoes, and they make good neighbors.

Raccoons

Raccoons can carry rabies. They often opt for chimneys and attics as substitutes for den sites. Adequate prevention consists of making sure garbage is properly stored, eliminating easy access such as overhanging limbs, and ensuring chimneys are in good repair with no cracks. NEVER feed raccoons or attempt to scare them with bare hands. Please remember they are wild animals.

Squirrels

If a squirrel gets in your house, block off the room it is located in and allow it only one exit through a door or window and wait for it to leave. If you have a squirrel in your fireplace, close the damper immediately. Then slightly open the damper and use a fishing net to capture the squirrel. Cover the net with a board and take the squirrel outside. Remember, squirrels can carry plague, and all direct contact should be avoided.

Ticks

The Vector and Cause

Colorado Tick Fever, common in spring and early summer in Boulder County, is caused by a virus. It is spread from animals to humans by a tick bite.

Rocky Mountain Spotted Fever, although rare in the western states, is also spread by ticks.

Symptoms and Treatment

Colorado Tick Fever is an acute, but usually not severe illness. Symptoms include fever, chills, muscle ache, and headache, usually occurring three to six days following a bite. There is no effective treatment, and complete recovery usually takes two to three weeks.

Rocky Mountain Spotted Fever begins with a chill and rapidly rising fever, beginning three to ten days after the bite of an infected tick. It is commonly associated with a rash spreading over the entire body. Prompt treatment by a physician will reduce disability and death.

Control and Prevention

• Become aware of tick-infested areas and use caution during tick season.
• When avoidance is impractical, search for ticks on your body often.
• Remove ticks promptly and carefully without crushing them. Grab the tick with tweezers, and lightly back the tick out of the skin, being careful not to pull too hard.
• Repellants containing diethyltoluamide (DEET) applied to CLOTHING are most effective. DEET contains chemicals which should not be applied to the skin. Wash all clothing after using DEET.

Plague

The Vector

Plague is a bacterial disease transmitted by the fleas of rodents and is widespread in the western United States. It is firmly established in rock squirrels, prairie dogs, wood rats, and other species of ground squirrels and chipmunks. It is also seen in fox squirrels and is introduced to tree squirrels common in city parks and Front Range residential areas. Wild rabbits may also become involved in the plague cycle.

Cause

The bacteria is transmitted to people through a flea bite and direct contact with infected animals. Fleas generally do not infect other animals unless their natural host (animal) is no longer available. Rock squirrels are the most significant plague host in Colorado. Domestic cats and dogs can contract plague by catching and eating infected rodents and rabbits or by being bitten by infective fleas. They can then carry infected fleas home to their owners or, especially with cats, serve as a direct source of infection.

Symptoms and Treatment

Symptoms include sudden onset of fever and chills, severe headache, muscle aches, nausea, vomiting, and general feeling of systemic (whole body) illness. Extreme pain and swelling in the lymph node is suggestive of bubonic plague.

Treatment with antibiotics is effective during the early stages of the disease. If diagnosis and appropriate treatment are delayed, life-threatening complications may follow. Consult your physician as soon as you experience these symptoms.

Control and Prevention

Rodent control should be carried out by a licensed professional. Poisoning of colonies should be avoided, because it releases fleas to the environment, causing additional risk to people. Infected colonies will be posted with warning signs, and access to pets should be restricted.

• Do not feed or entice any rodent or rabbit.
• Eliminate rodent harborage, such as piles of lumber, broken cement, and trash or weeds.
• Keep foundations in good repair, and trim back overhanging trees from the roof and windows.
• Keep away from rodent-infested areas when camping.
• Avoid contact with all sick or dead rodents.
• Report instances of sick or dead rodents in the county to Boulder County Public Health at (303) 441-1180.
• While hiking, treat pants, socks, shoe tops, and shirts with insect repellant.
• Keep all dogs leashed, and restrict cats from roaming in rodent-infested areas.
• Report all bites from wild carnivores and cats to Public Health at (303) 441-1180.
• If onset of illness occurs within 2-6 days after activities in the outdoors, report it to your physician.

Hantavirus

Information taken from the Colorado Department of Public Health & Environment brochure

Hantavirus is caused by a virus that is primarily carried by deer mice. The virus is shed in the urine, saliva, and feces of infected mice. People may become infected by breathing in the dust of dried feces from mice nests or surfaces contaminated with mice droppings. Hantavirus Pulmonary Syndrome (HPS) begins one to six weeks after exposure to rodent feces; however, many patients will not give a history of rodent exposure. The early symptoms of HPS include fever, myalgia, nausea, vomiting, and diarrhea that persists from one to seven days before advancing to the cardiopulmonary phase of the illness.

Deer mice are very common in rural areas throughout the U.S., but they are not usually found in cities or suburbs. Mice do not seem to be affected by hantavirus they carry, and household pets do not transmit the virus. Insects also do not appear to be carriers. Hantaviruses are not spread from one person to another; there have been no cases where the disease has spread among family members or health care workers.

What activities could put you at risk?

• Living in buildings infested with rodents.
• Cleaning barns, outbuildings, or grain storage areas.
• Working in confined spaces infested with rodents.
• Clearing shrubbery or doing hand-plowing.

What clean-up tips should I use?

• DO NOT sweep or dry vacuum rodent droppings until the droppings have been sprayed with disinfectant solution.
• Open windows and doors that allow fresh air to flow.
• Spray droppings and nest material with disinfectant and allow to soak for 10 to 15 minutes before cleaning.
• Clean up with a mop, sponge, or wet vacuum.
• Spray or wet clean carpets with a disinfectant.
• Clean bedding and clothing with hot, soapy water.

Animals Killed on Roads

If a deer is killed on a city or county road, call the State Division of Wildlife at (303) 291-7546.

Boulder County is not responsible for dead animals on the roadway. If you see a dead animal on the road, please call Colorado Animal Disposal at (303) 989-9319.

Boulder County does not endorse any private companies.

For more information, call 303-441-1564.