Mouse Specific Occupational Health & Safety Risks

Someone working in a facility with mice could potentially be exposed to any zoonotic disease agent affecting wild rodents. In practice, however, these conditions are very rare. Modern laboratory animal facilities pay particular attention to vermin control, thereby reducing the likelihood of infection of laboratory mice by their wild counterparts. However, there is always the potential for breaks to occur.

The major health risk to individuals working with rodents is the development of an allergy. Conditioned, colony-born rodents are generally docile, but may occasionally inflict injury such as a bite or scratch. Staff assigned to rodent areas should be trained in handling techniques and protective clothing requirements prior to beginning hands-on work.

Recommended Preventative Measures

• Training on proper mouse handling techniques is available through CLAC

• Follow any posted Personal Protective Clothing requirements

• Wash hands after handling animals or related equipment

• When seeking medical advice for any illness, inform your physician that you work with rodents.

To reduce the risk of exposure to allergens when rodents are transported to or used in laboratories, staff are advised to adhere to the following practices:

• Dust masks should be worn at all times when working with rodents; whenever there is a risk of aerosol transmission of a zoonotic agent, approved respirator masks (e.g., Type N95 by 3M company) should be worn instead of dust masks

• Perform procedures in a laminar flow hood whenever possible

• Minimize wearing protective clothing such as lab coats outside of animal areas

• Use disposable supplies whenever possible

• Sanitize lab work areas after animal work.

Response to Injury

For all incurred injuries incurred when working with rodents:

• Wash any injured site with soap and water for at least 5 minutes

• Control bleeding by applying direct pressure with a sterile gauze or bandage

• Cover wound with clean bandage (do not apply ointment or spray)

• Seek advice from emergency room physician.

Specific Mouse Risks

Lymphocytic choriomeningitis:

Lymphocytic Choriomeningitis Virus LCMV is an arenavirus commonly associated with hamsters, but does infect mice. In 1965, during an outbreak in hamsters, 23 human cases were recorded. Now rare in laboratory animal facilities, LCMV has been eliminated from most vendors through breeding and viral screening of their colonies.

Reservoir/source of infection to people: Wild mice worldwide are the reservoir of infection to laboratory and pet rodents. Mice and hamsters are the only animals known to develop latent infection; experimentally transplanted tumors are the other source of infection to mice; • Transmission: Contact with tissues including tumor, feces, urine, and aerosolization of all of the above; • Disease in people: Flu-like symptoms, mild to severe.

Leptospirosis:

Leptospira spp. are bacteria found in many animals but are most commonly associated with livestock and dogs. Transmission from laboratory rodents to people has been reported.