Hazards Associated with Laboratory Animals
EMD 545b
Lecture #11
Physical Hazards
Ergonomic issues
Strained postures
Heavy lifts
Repetitive motion
Slips/Trips/Falls
Noise/Heat in Cage Washing Rooms
Bites
Risks of Work with Research Animals
Risks of Work with Research Animals
Risks of Work with Research Animals
Zoonoses
Infectious diseases capable of being transmitted from
animals to humans
Dogs and Cats – Rabies Virus
Feral animals represent the greatest risk
Acquire animals documented free of disease
Pre-exposure immunization required for exposed personnel (3 shot series)
Titers after vaccination and at 2 year intervals
Post bite evaluation for need for Rabies booster, wound prophylaxis, tetanus
Dog or Cat - Bites
Infections common
Organisms are Staph, Strep, Pasturella, anaerobes
C. canimorsus
Proper wound care/ tetanus immunization
Appropriate antibiotic prophylaxis
CatsCat scratch disease--Bartonella henselae
Toxoplasmosis---T.gondii
Especially important in immunocompromised/pregnant workers
Prevention--good hygiene
May offer temporary transfer to pregnant women without immunity to Toxoplasma
Yersinia pestis--fleas from cats/ rodents in southwest
Dog and Cat
Dermatomycosis--ringworm
Gastrointestinal infections---Salmonella, Campylobacter, Shigella,
Prevent by prompt recognition and isolation of ill animals
Rodents
Rat Bite Fever-Spirillum minor, Streptobaccilis moniliformis
Leptospirosis
Lymphocytic choriomeningitis
Sheep--Q fever (Coxiella burnetti)
Aerosols from urine, feces, birth products
Persists in environment
Nonspecific viral symptoms but serious illness in those with pre-existing liver or valvular heart disease
Sheep
Hepatitis Viruses
Hepatitis A:
Enteric (oral/fecal spread).
No chronic carrier state
Reservoir is man, but occasionally NHP’s.
Vaccine available- not routinely recommended for NHP workers.
Hepatitis Viruses
Hepatitis BBloodborne
Low mortality (1 % case fatality rate)
Up to 10% of those infected become chronic carriers with high incidence of cirrhosis and liver cancer.
Reservoir is man, chimps are susceptible.
Vaccine available, but only indicated for potential human BBP exposure.
Hepatitis Virus
Hepatitis CBloodborne.
Disease is milder vs. hepatitis B, but higher rate of chronic carriers.
Reservoir is man, chimps are susceptible.
No vaccine, but treatment within weeks of infection can prevent chronic disease.
Tetanus
Caused by exotoxin of Clostridium tetani
Uncommon : 1995-1996, 124 U.S. cases reported.
Case fatality rate proportional to age (2.3% in ages 20-39, 18% for >60) and availability of adequate medical care.
Reservoir is intestines of most animals, including humans and NHP’s
Tuberculosis
Reservoir is man and rarely NHP’s, badgers, and other mammals.
NHP’s are susceptible.
Screening is done by intradermal challenge with purified protein from M. bovis. Positive tests indicate previous infection. Chest x-rays are then required to r/o active disease.
Enteric Infections
Viral:Hepatitis A and E
Possibly rotaviral gastroenteritis
Bacterial:Campylobacter jejuni and coli (NHP’s may be a reservoir).
Salmonella (NHP’s may be a reservoir)
Shigella (man is reservoir, but outbreaks have been reported in NHP colonies).
Bacterial Infections from Bite Wounds
>200 species of bacteria in the mouths of many animals, including humans.
Streptococcal species, staphylococcal species, tetanus.
Bite wounds need to be thoroughly cleaned and debrided.
Prophylaxis for moderate to deep bites with Amoxacillin/clavulinic acid (Augmentin).
Non- Human Primates (NHP)
Unique hazards
size intelligencestrength
Zoonotic hazardsherpes B virus (Macaques)SalmonellaTBSIV, STLVendogenous retroviruses
Simian Immunodeficiency Virus (SIV)
NHP’s may be infected with several retroviruses, including simian immunodeficiency virus, simian spumaviruses (foamy viruses or SFV), simian T-lymphotrophic viruses (STLV), and/or simian type D retroviruses (SRV).
Non Human Primates
B virus--Cercopithecine herpesvirus 1
Hepatitis A
Hepatitis B
Other exotic agents--Marburg, Ebola, Simian immunodefeciency virus
Non Human Primates
Screen workers for risk factors
Enroll in serum banking is recommended
Prompt recognition and treatment of injuries
B Virus (Cercopithecine Herpesvirus 1)
Naturally occurring infection seen only in genus Macaca (rhesus, cynomolgus, pig-tailed, others).
Very high prevalence of captive macaques >2.5 years old have been infected. 20% for animals < 2.5 years old.
Infected monkeys may have mild or no symptoms
B Virus (Cercopithecine Herpesvirus 1)
Human disease is rare and has been identified in about 50 cases and well-documented in 26 cases.~70% case fatality rate in humans
Potentially infectious material: ocular, oral, genital secretions
Central nervous system tissue and CSF
Primary cell cultures from macaque kidneys
Transmission of CHV-1
Route of Exposurebites and scratchesneedlestick injuries with contaminated needles or scalpels, often during surgeryeye and mucous membrane exposure to body fluids or particulates from animalmost recent death (12/10/97) attributed to an unknown particle which entered the eye of a researcher at Yerkes Primate Center during observation without PPE
Exposures to Non-Human Primates
Immediate Response:Mucous membrane: flush in an eye wash or potable water for a minimum of 15 minutes.
Skin exposures: Wash with soap and water or antiseptic for 15 minutes Consider dilute solutions of bleach (Dakin’s solution) for skin and wounds.
Safe Handling of Non-Human Primates
Full-length leather gloves and appropriate PPE
Squeeze-back cages
Behavioral conditioning or training
Handling NHPs
ABSL-2 requiredRestraint required
squeeze-back cagespole and collarsprimate chairs
Cover long hair and remove all jewelry.
Protection of NHP workersGloves
appropriate to useGowns/coverallsFace protection
gogglesface shieldsurgical mask or respirator
Otherhead and beard coversshoe covers/boots
NHP Facilities: Access Control and Staff Training
Training (more extensive & periodic)
Personnel must enroll in med surveillance program
Restricted/controlled access
Animal BSL2 containment conditions
Written emergency response plans
Laboratory Animal Allergy
10% of those without previous history will develop allergy to lab animals
70% of those with pre-existing allergies will develop a new allergy
Overall risk is 30%
Allergies
Symptoms---upper respiratory irritation, can progress to asthma and anaphylaxis
Screen with personal and family history
Allergy ScreeningPersonal history of allergies/ atopy/eczema strongly associated with increased risk
Family history of allergy also important
Only test in case of pre-existing symptoms when patient plans on working with that species
Periodic screen by history for development of new allergies in high risk patients
Common allergy sources
Rats/ Mice--major allergens in urine/saliva
Cats--sebaceous glands, hair, saliva
Dogs--saliva, hair, skin
Rabbits--fur,saliva, urine
Birds--droppings
Bedding
Note non occupational sources of exposure
Prevention of Lab Animal Associated Allergies
Employee selection
Biosafety cabinets
Filter top cages
Ventilated cage racks
Choice of bedding
Animal density
Proper humidity
Personal protective equipment
Treatment of Lab Animal Associated Allergies
Prevention is preferred
Education of employees
Proper use of personal protective equipment
Re-assign employees when needed
Medical treatment to reduce symptoms
Risk Factors for Development of LAA
Exposure to allergensdurationfrequencyintensity
Previous allergic conditionsOther predisposing conditions
illnessimmunocompromisedpets
Routes of exposure for LAAs
Routes of exposure for LAAs
LAA: Exposure Control
Engineering controls: enclosure dilution ventilation
Administrative controlsreduce time with animalsreduce density of animalshousekeeping practices
Personal protective equipmentrespirators and clothing
Medical surveillance (screening and ongoing monitoring)
LAA: Exposure Control
Administrative Considerations
The key elements in the review and approval of animal experiments
Institutional Animal Care and Use Committee (IACUC)Institutional Biosafety Committee (IBC)Environmental Health and Safety/ Biosafety Officer (BSO)Director of Veterinary Services
Communication and coordination is important
work together to review protocols
Administrative Considerations
Consider unique aspects of each protocolIACUC/IBC assignment of:
locationcontainment level
All handlers must be informed of:medical surveillance requirementsspecific risks of species, agentsigns/symptoms of infectioncontainment protocol selectedemergency response procedures