OHSP APPENDIX V

Zoonoses
While zoonotic risks (transmission of disease from animal to man) do exist, the risk is relatively small in a conditioned, colony-born population of laboratory rodents and rabbits. However, the risk of acquiring zoonotic disease increases substantially if an individual is immunocompromised. Development of allergies is by far the greatest risk posed by rodents and rabbits. Fish pose even lesser risk.

Personal protective equipment, safe and proper handling of animals and good hygiene helps to minimize scratches and bites, splashes, and direct contact with and inhalation of with fur, saliva, urine or other fluids, which may result in transmission of disease to man. The risk of aerosol transmission of a zoonotic agent can be minimized by the use of approved respirator masks.

The following are zoonotic disease that can be transmitted from rodents:

• Lymphocytic choriomeningitis (LCM) - an arena virus which has been eliminated from most vendor colonies through breeding and viral screening; reservoir - mice and hamsters; transmission - direct contact with tissues including tumor, feces, urine, and aerosol inhalation; symptoms in humans - mild to severe flu.

• Leptospirosis (Leptospira spp.) - bacteria; reservoir - rats, mice, voles, hedgehogs, gerbils, squirrels, rabbits, hamsters, reptiles, dogs, sheep, goats, horses, standing water; transmission - direct contact with urine or tissues via skin abrasions or contact with mucous membranes; aerosol inhalation and ingestion; symptoms in humans - mild to severe flu, death.

• Rat bite fever: - bacteria (Streptobacillus moniliformis or Spirillum minus); reservoir - rats; transmission - bite of infected rat; symptoms in humans - fever, lymphadenopathy, swelling at site of wound.; incubation period usually 1-3 days, up to 6 weeks- may cause arthritis in untreated patients; treatable with penicillin

• Hantavirus Infection: reservoir - wild mice and rats; transmission - aerosol inhalation; symptoms in humans - fever, headache, myalgia and petechiae and other hemmorhagic symptoms, including anemia, gastrointestinal bleeding etc.

• Salmonella spp. and Campylobacter spp. - rodents; transmission - fecal/oral; symptoms in humans - diarrhea, dysentery.

The following are zoonotic disease that can be transmitted from rabbits:

• Pasteurella multocida: bacteria in the oral cavity or upper respiratory tract of rabbits - rabbit bite or scratch; symptoms in humans - local inflammation around the bite or scratch, possibly leading to abscess formation with systemic symptoms.

• Cryptosporidiosis: extracellular protozoal organism, cryptospordium - waterborne or fecal-oral transmission; symptoms in humans - no symptoms to mild enteritis to marked watery diarrhea; self-limited infection lasting a few days to 2 weeks.

• Other Potential Disease Associated with rabbits but not commonly associated with laboratory rabbits: Brucella suis biotype 2, Cheyletiella infestation, Francisella tularensis, Plague, Q-fever, Trichophyton mentagrophytes.

• Allergic Reactions to Rabbits: major glycoprotein allergen in rabbit fur; minor allergenic components in saliva and urine

The following are zoonotic disease that can be transmitted from zebrafish (Danio rerio).

Potential Zoonotic Diseases
Aside from food poisonings, the overall incidence of transmission of disease-producing agents from fish to humans is low. There are, however, a number of agents that are found in fish and aquarium water that have the potential to be transmitted to humans. In general, humans contract fishborne disease through ingestion of infected fish tissues or aquarium water, or by contamination of lacerated or abraded skin. An important feature of many bacterial and protozoal organisms is their opportunistic nature. The development of disease in the human host often requires a preexisting state that compromises the immune system. If you have an immune-compromising medical condition or you are taking medications that impair your immune system (steroids, immunosuppressive drugs, or chemotherapy) you are at-risk for contracting a fishborne disease and should consult your physician. The following is a list of known and potential fishborne zoonoses.

• Mycobacterium - Organisms in the genus Mycobacterium are nonmotile, acid-fast rods. Two species, M. fortuitum and M. marinum, are recognized as pathogens of tropical fish. Humans are typically infected by contamination of lacerated or abraded skin with aquarium water or fish contact. A localized granulomatous nodule may form at the site of infection, most commonly on hands or fingers. The granulomas usually appear approximately 6-8 weeks after exposure to the organism. They initially appear as reddish bumps (papules) that slowly enlarge into purplish nodules. The infection can spread to nearby lymph nodes. More disseminated forms of the disease are likely in immunocompromised individuals. It is possible for these species of mycobacterium to cause some degree of positive reaction to the tuberculin skin test.

• Aeromonas spp.- Aeromonad organisms are facultative anaerobic, gram-negative rods. These organisms can produce septicemia in infected fish. The species most commonly isolated is A. hydrophilia. It is found world wide in tropical fresh water and is considered part of the normal intestinal microflora of healthy fish. Humans infected with Aeromonas may show a variety of clinical signs, but the two most common syndromes are gastroenteritis and localized wound infections. Again, infections are more common and serious in the immunocompromised individual..

• Other Bacteria and Protozoa - Below is a list of additional zoonotic organisms that have been documented in fish or aquarium water. Human infections are typically acquired through ingestion of contaminated water resulting in gastroenteritis symptoms or from wound contamination...

Gram-negative Organisms: Plesiomonas shigelloides, Pseudomonas fluorescens, Escherichia coli, Salmonella spp., Klebsiella spp., Edwardsiella tarda
Gram-positive Organisms: Streptococcus, Staphylcocccus, Clostridium, Erysipelothrix, Nocardia
Protozoa: Cryptosporidium

Special Considerations
Animal care and use personnel are advised to inform the OHS providers of pregnancy, illness, or decreased immunocompetence. The OHS providers will evaluate individuals on a case-by-case basis and with due consideration to the risks associated with laboratory animal exposure and modify their OHS surveillance, training, and program participation as needed to ensure their health and safety in the laboratory animal research environment.