Hazards Associated with Laboratory Animals EMD 545b Lecture #11.

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