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Stanislaus COE |  AR  4319.44, 4119.44,4219.44  Personnel

Prevention Of The Exposure To Hantavirus   

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Hantavirus is a family of virus found in rodents. These viruses have caused serious health problems in other parts of the world. The Hantavirus that we are concerned about is unique to North America. It attacks the lungs resulting in a disease termed Adult Respiratory Distress Syndrome (ARDS). Typical cases seem similar to the flu: high fever, muscle aches, cough and headache. These symptoms typically develop 1-2 weeks after exposure, but could be up to six weeks.


Rodents, especially the deer mouse, are the primary host of Hantavirus, although recent research has shown that other small mammals can be infected as well. Infected rodents shed Hantavirus in their saliva, urine, or droppings. Infection can occur when saliva, urine or droppings from an infected rodent are inhaled as an aerosol produced directly from the rodent or when the dried material is distributed in such a way that creates dust that is inhaled. Infection can also occur when the rodent excreta are introduced into a cut, abrasion or mucus membrane. People have also become infected after a rodent bite.

Insects, such as mosquitoes and fleas, are not known to be sources of infection. Person to person transmission has not been associated with any Hantavirus outbreak, including the 1993 outbreak in the Four Corners area of the United States.


This risk is low for persons who do not have direct rodent contact and who do not live or work in dwellings heavily contaminated with rodent droppings. However, approximately 33% of the infections are believed to be related to an occupational exposure. While health precautions apply to all employees, the occupational risk for SCOE staff would be for maintenance staff, housekeeping and custodial staff, and staff working in buildings with evidence of rodent infestation.

Risk reduction includes specific recommendations for:

1. Eliminating rodents and their excreta inside buildings.

2. Preventing Hanatvirus exposure while cleaning up rodent contaminated areas.

3. Minimizing risk while performing fields duties.

This policy is based on the assumption that all contact with wild rodents and their excreta are infected or contaminated.

Prevention Of Disease

The best current approach for disease prevention and control is risk reduction through environmental practices that deter rodents from colonizing the home and work environment. It is likely that the greatest risk of becoming infected is through the inhalation of aerosols of excreta, saliva, or urine produced directly by rodents. The risk is more likely to occur indoors:

* First step is to keep rodents out of buildings

* Buildings already infested require that the infestation be abated and cleaned up.

Level One-Routine Office Situation


1. Do not use vacuum cleaners or sweep with dry brooms, which will create dust.

2. Spray dead rodents, rodent nests, droppings or other items that have been contaminated by rodents with one to five dilution of house hold bleach in a water solution. Soak the material thoroughly and place in a plastic bag. Seal, place in a second plastic bag and dispose of in the regular trash.

3. Disinfect countertops, cabinets, drawers, and other durable surfaces by washing with a solution of detergent, water and disinfectant. Allow to air dry.

Level Two-Industrial Exposure

Industrial exposure of SCOE employees are those who have unpredictable or incidental contact with rodents or their habitation, such as maintenance workers and groundskeepers.

General Safety Procedures:

* Wear plastic or rubber gloves when handling dead rodents, contaminated traps, or when cleaning up rodent material.

* Avoid direct contact with rodents. Avoid startling rodents, especially in confined spaces such as attics or crawl spaces. Rodents typically urinate when startled, thus creating and aerosol mist that can be inhaled.

* Protective goggles should be worn if contact of material with the eye is anticipated. The use of appropriate respiratory protection (facemask) should be considered when contaminated material might become aerosolized.

* Rodent debris should be thoroughly wetted with a 1-5 dilution of household bleach in water to reduce formation of dust aerosols. Debris should be WIPED up and placed in double plastic bags for disposal. Do not use vacuum cleaners or sweep with dry brooms that will create dust.

* Persons involved in the cleanup should wear gloves, protective goggles, and disposable facemasks that will provide protection from exposure to dust.

* Spray dead rodents, rodent nests, droppings or other items that have been contaminated by rodents with the disinfectant solution. Soak the material thoroughly and place in a plastic bag. Seal, place in a second plastic bag, and dispose of it in the trash.

* Disinfect countertops, cabinets, drawers, and other durable surfaces by washing with a solution of detergent, water, and disinfectant. Allow to air dry.

Level Three: Heavy Rodent Infestation

* The following are special precautions for cleaning buildings with heavy rodent infestations (e.g. piles of feces or numerous dead animals). These precautions may also apply to vacant dwellings that have attracted numbers of rodents while unoccupied. Rodent infestation can be determined directly from the observation of animals or indirectly from the presence of rodent droppings in closets, cabinets, or on the floors. The same precautions should be used as for Level Two with the addition of the following:

* Wear appropriate ate protective clothing including gloves, coveralls, boots, lab coats, coveralls, goggles, and an appropriate respiratory protection device such as HEPA air filter or a powered air purifying respirator (PAPR) with HEPA filters.

* All field staff shall complete appropriate respiratory use training prior to participating in any cleanup work. Eating, drinking, and smoking is prohibited in areas where respirators are in use.

* Cleaning, buildings with heavy rodent infestation:

1. Dwellings should be aired-out for at least 30 minutes before wetting and wiping up debris.

2. Wear disposable coveralls, hair covering, rubber boots or disposable foot covers, plastic or rubber gloves, protective goggles, and an appropriate respiratory device.

3. Dispose of rodents and rodent material.

4. Protective gear decontamination procedure:

Spray each worker with a 20% bleach solution, from the neck down, taking care to avoid the face.

5. Remove disposal coveralls, head cover, foot covers, respirator and gloves.

6. Decontaminated gear and be bagged and disposed of in regular trash.

7. Wash hand with soap and water for at least 15 seconds after removing gloves, Shower with soap and water as soon as possible after removing protective gear.

* Recommended supplies for cleanup: Rubber gloves, goggles, portable sprayer, spray bottles, disinfectant such as 20% household bleach, respirators with a HEPA (High Efficiency Particulate Air) filters, buckets, trash bags, garbage cans, snap traps, disposable coveralls, rubber boots, disposable hair covering, and duct tape.

* Before opening a "decontaminated" area, make sure, by frequent inspections and re-decontamination and trapping, that area is rodent and rodent debris free.

Staff Inservice

This Hantavirus policy represents the Stanislaus County Office of Education's (SCOE) recommendations for minimizing the likelihood of human exposure to Hantavirus infected rodents. The Director of Health Services in cooperation with SCOE supervisors shall provide information and training on a regular basis to appropriate staff regarding this policy including the risk of disease and protective measures. After the initial inservice program in 1998, only new staff will be inserviced unless the policy changes or new information is forthcoming.


approved: February 4, 2003 Modesto, California