Division of Environmental Health and Sustainability

Frequently Asked Vector Control Questions

In order to provide quick responses to your questions, we have prepared this list of frequently asked questions. You may find the answer you seek without waiting for a response from our staff. If your question is not answered by this list, please feel free to send us a note.

How do I get a license to apply pesticides?

Contact the Colorado Department of Agriculture Plant Industries Division at (303) 239-4179 for pesticide licensing/certification information.

What is Hantavirus pulmonary syndrome (HPS)?

HPS is a severe viral infection characterized by respiratory distress. The disease begins with a prodromal, or early, stage characterized by fever, headache and severe myalgia (muscle pain) especially in the lower back. Within 1-5 days the person develops a cough, shortness of breath and difficulty breathing. Once these breathing difficulties appear the disease may rapidly progress to severe respiratory and cardiac failure, during which the patient requires intubation and advanced life-support assistance.

Where does HPS occur?

This disease is a public health problem in the western hemisphere, and cases have been found throughout the Americas. The case fatality is high and effective treatment is not yet available. The disease currently has a case fatality rate of approximately 40%.

What causes Hantavirus pulmonary syndrome?

Where do these rodents live?

The combined distributions of the New World rats and mice cover all of North, Central, and South America. Therefore, HPS is not just a problem in the Southwestern U.S. Since the discovery of Sin Nombre virus, HPS cases have been recognized in 30 states of the U.S., in Canada, and six countries in Latin America.

Who can get HPS?

How can one get HPS?

The infected rodents excrete the virus in their urine, droppings, and saliva. These droppings contaminate dirt and dust that when disturbed becomes airborne. People get infected by inhaling airborne particles of the virus or by direct contact with rodents, their droppings, or nests.

What is the incubation period?

The incubation period varies widely, but ranges from 1 to 6 weeks, with an average of 2-3 weeks.

What are the symptoms?

The early symptoms include fever, headache, myalgia (muscle pain), severe abdominal, joint and lower back pain, nausea and vomiting. A cough and shortness of breath usually develop 1 to 5 days after the onset of symptoms. The primary symptom of HPS is difficulty in breathing due to fluid build-up in the lungs. This can quickly progress to respiratory failure.

How is HPS treated?

Currently there is no effective drug treatment for HPS. When hantavirus infection is suspected or confirmed, early admission to a hospital where careful monitoring, treatment of symptoms, and good supportive therapy can be provided is important. If you have had exposure to rodents and experience symptoms mentioned above, it would probably be helpful to mention the exposure to your physician. A quick diagnosis helps the physician take the appropriate measures in managing the patient.

How can HPS be prevented?

Avoid rodent contact by taking the following measures:

1. Always limit food sources that will attract rodents both inside and outside the home. Keep pet food and livestock feed in rodent-proof containers. Clean-up spillage from bird feeders.

2. Limit possible nesting sites in or near the home. Keep grass and vegetation near homes trimmed short. Store firewood above ground and away from the house. Remove wood and junk piles, abandon vehicles, equipment and other sources of shelter from the property.

3. Prevent rodent entrance into the home. Seal all holes or cracks 1/4 inch or larger with steel wool, caulking, metal screening or flashing. Insure weather seals under doors are in good repair and fit tightly when the door is closed.

4. If rodents are present in the home, eliminate them by using "snap-traps" baited with a peanut butter/oatmeal mix. Trapping success will be increased if food sources have been eliminated and entrances to the building sealed to keep new mice from moving in. Continue trapping efforts as long as rodent presence is suspected in the home.

5. Use a solution of household bleach (1 cup bleach/gallon of water) to disinfect rodents carcasses before handling. Spray the rodent and trap and allow to sit for 5-10 minutes Wear rubber gloves when handling trapped rodents. Disinfect the gloves and the trap afterward.

6. Air out rodent infested buildings or areas at least 30 minutes before cleaning. Do not sweep or dry vacuum rodent contaminated surfaces which may stir up the dust and allow potentially contaminated dust to be breathed in. Spray contaminated materials with the bleach solution and allow it to soak in 5-10 minutes before cleaning them with a mop, sponge or wet (shop) vacuum. Wear gloves.

7. In heavily rodent infested areas or situations where ventilation and/or wet clean-up can not be effectively done, use a respirator with a high efficiency particulate air (HEPA or N-100 equivalent) filter.

8. When camping or sleeping outdoors, avoid disturbing or sleeping near rodent droppings and/or burrows. Sleep in tents with floors, above ground or on a ground cloth, not directly on the ground.

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