Occupational Issues in Laboratory Animal Handling Raj Puri, MD, MPH - PDF document

Occupational Issues in Laboratory Animal Handling Raj Puri, MD, MPH Clinical Assistant Professor of Medicine, Section of Occupational Medicine Director of Strategic Health Initiatives & Innovation Stanford University Disclosure  I have no financial interests and nothing to disclose Outline I. Introduction II. Oversight and Ethics III. Animal handling: definition and techniques IV. Unique Occupational hazards in lab animals V. Cases VI. Summary

Introduction  Occupational safety and health considerations are primary concerns of animal care and use program management regardless of the size of the program or facility  Hazard identification must be undertaken  Job hazard analysis (JHA) or job safety analysis (JSA) – subsequent risk assessment  Mitigation of identified hazards should follow the broadly accepted approach using the “hierarchy of controls” strategy Roles and Responsibilities of Overseers  Strong, institutional commitment to safe and compassionate conduct of research  Team-based approach – At a minimum, occupational safety and health management team is composed of a veterinarian with experience and training in the species – Facility manager – Safety and health specialist  Animal care and use committee or oversight body – ensuring an effective occupational safety and health program – AAALAC accreditation (nonprofit and voluntary), every 3 years

Ethical and legal responsibility • Careful handling so not to suffer from unnecessary pain • Providing good care towards the health and well-being of animals • Animal awareness of the handler’s presence before attempting to restrain them, particularly if the animal is initially asleep • Reduces stress for the animal and decreases risk to bite injuries Types of Animals Used in Labs History What is Animal Handling?  Definition: – Term describing how humans work with, respond to, and interact with animals within their surroundings – Includes all species, and all parts of production  Types of workers doing the handling – Researchers eg performing injections, surgeries, etc – Staff eg animal technicians, census techs, etc

Specifics of Animal Handling 1 ?  Holding and restraining  Oral feeding  Subcutaneous and Intraperitoneal injections  Blood collections eg tail veins, etc  Husbandry practices eg including sanitation, diet, and adequate space  Health monitoring and record keeping  Species interactions, in the same room or area  Cages with bedding, cage changing and dumping soiled bedding in cage wash area  Surgeries and anesthesia administration • 1 AAALAC international 2020 PPE examples Hazards PPE Source: NIH ‐ Animal Research Advisory Committee, Guidelines for personnel protection in animal facilities, 2016 Types of lab animals  Large – Monkeys, pigs, dogs and cats  Small – Rodents (mice and rats), rabbits and frogs

Lab animal use  • “In Vivo” experiments when the whole intact animal is used  • “Ex Vivo” experiments when only a part of the animal is used – organ (e. g. heart, uterus, trachea. etc. ) – tissue (e. g. skeletal muscle) or cells (e. g. blood cells) Mice  Most common mammal among laboratory animals  Characteristics – Mice are small weighing about 18 -30 g. – Very sensitive and consume small doses of drugs – Can be easily handled – Highly exploring and mobile – Drugs are best injected intraperitoneal or intravenously into one of their superficial tail veins Mouse handling  1) Typically restraining by the tail – Mice may be picked up by grasping the base of the tail – Do not grasp the tip of the tail, as this may cause the skin to be stripped off – Only used for brief restraint e.g. transferring animals from cage to cage – Never suspend the mouse for prolonged periods of time by its tail  2) Forceps Restraint – Picked up with rubber tipped forceps  gently grasping the animal by the scruff of the neck or the base of the tail  short-term procedures such as transferring animals to a new cage  Never suspend the animal for a prolonged period of time with the forceps.

Mouse handling  3) Two-Handed Method Technical procedures: injection and blood collection – Place the mouse on a rough surface while holding the tail firmly  Note: Smooth surface will frighten the mouse because it cannot get a foothold. This may cause it to turn around and bite in its attempt to escape. Grasp the nape gently and firmly with your free hand and lift the mouse – Scruff can be grasped between the thumb and forefinger whilst maintaining a grip on the tail Mouse handling  4) One-handed method – Purpose: injections, ear tagging – Place the mouse’s tail between the last two fingers of the hand that is holding the nape Unique Hazards in Care and Use of Lab Animals  A. Allergen exposure  B. Physical hazards  C. Environmental Hazards  D. Zoonotic diseases  E. Hazardous material exposure

Allergens  May develop allergic reactions to an animal protein – found in dander, hair, urine, and saliva – animal allergens carried through air and surfaces – tend to stick to fur, dander, bedding, and dust – those who develop allergy do so within the first 12 months of contact with an animal at home or in the workplace – earliest symptoms consist of upper airway and skin complaints e.g. nasal congestion or stuffiness, runny nose with nasal drainage, sneezing, red and irritated eyes, skin itching, and hives  mean time to onset of nasal symptoms is seven months from the first exposure – advanced cases consist of lower airway findings, e.g. cough, wheeze, SOB, asthma, and in rare circumstances, anaphylaxis Allergen Risk  workers at greatest risk to laboratory animal proteins are those with a hx of allergic reactions to household pets  those at increased risk include those with hx of asthma, seasonal sinus issues, eczema, and other allergies  risks can be minimized by engineering controls, e.g. air containment devices (e.g., biological safety cabinets and chemical fume hoods) and waste handling equipment (e.g., HEPA-filtered bedding dump stations)  respiratory exposures can be controlled by housing animals in filter- topped cages and working in a well-ventilated area, such as a room with nonrecirculating room air or near a fume hood Allergen Risk  standard operating procedures promoting frequent washing of hands with soap and water – alcohol-based hand rubs can be used but they are not effective for allergens and not a substitution for hand washing with soap  disposable respirator, such as an N-95, or other negative-pressure respirator, such as a PAPR

Laboratory Animal Allergy (LAA)  Laboratory animal allergy (LAA) is the manifestation of an IgE- associated sensitization to animal proteins – a common cause of occupational allergy and asthma – a condition that historically afflicted up to 20% of a highly trained workforce  conventional open cages – evidence of an exposure–response relationship between airborne rat urinary proteins and LAA has long been established  increasing risks of IgE sensitisation and LAA at higher levels of exposure  evidence for allergy to mouse proteins is less clear Laboratory Animal Allergy (LAA)  Risks of LAA are highest in the early years of employment and an estimated 95% of individuals who develop LAA do so in the first 3 years of exposure  Most studies found no association between smoking and sensitization to, primarily, rats but also other laboratory animal allergens  Atopy was strongly associated with sensitization to mice (Palmberg, 2015; Krop et al, 2011)  Survey study of 750 workers by Feary et al. (2019) demonstrated: – LAA can be “largely prevented” in modern research units using individually ventilated cages (IVCs) to contain aeroallergen exposure and use of respiratory protection  Asymptomatic sensitization is well recognized  may reflect a permanent state or transition phase from immunological Individually Ventilated Cages (IVC)

LAA diagnosis and treatment  Medical evaluation  Hx and PE: nature, severity and pattern of symptoms, temporality  spiro/PFT’s  performed before the beginning of the workweek and towards the end of the shift  decline of at least 20% of the FEV 1 or 25% of the FEF 25-75 is considered significant  symptomatic employee may be given a peak flow meter  serologic testing in occ clinic eg urine, epithelium, and salivary (mouse/rat/rabbit)  daily lower respiratory symptoms may require short- and long-acting beta- receptor agonist bronchodilator therapy and possibly inhaled corticosteroids  Referral to allergist, if needed  Eliminating exposure to allergens is the treatment of choice, if possible  Fitted for N-95 mask  OTC antihistamines eg Zyrtec, Allegra, Claritin prior to exposure LAA Job options  reducing the airborne allergen through engineering controls  modifying work practices – job or task rotation initiatives – review personal respiratory protection equipment to enhance comfort and practicality for worker Physical Hazards  MSK injuries (ergo): Strains, sprains, back injuries a. Caused by awkward postures (collecting blood/tissue samples, or administering multiple vaccinations)  highly repetitive motions, hand force (when restraining animals), heavy, frequent, or awkward lifting b. Slips, trips and falls: might occur when walking on uneven or wet surfaces (spills), PPE can limit your range of motion predisposing to fall